The Great Big Biology Review Book
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The Great Big Biology Review Book
In preparation for the Missouri
HONORS BIOLOGY
End of Course Exam
Spring
If you find this packet, please return it to:
Student Name: _____________________________
Student Phone Number: ___________________________
Biology Teacher: ___________________________
Biology 250 Missouri End of Course Exam (EOC)
Prioritized CLE Mastery Tracking
|CLE |Topic(s) |Page in Review |Review Questions Completed |Mastery Quiz Passed |
| | |Packet | | |
| | | |Date |Signature |Date |Signature |
|3.1.B.a |Cells divide and differentiate |4 | | | | |
|3.1.C.b |Structure and Function of Cell |6 | | | | |
| |Organelles | | | | | |
|3.2.A.c |Organelle Interactions |9 | | | | |
|3.2.B.a |Interrelatedness of Photosynthesis and |11 | | | | |
| |Cell Respiration | | | | | |
|3.2.B.b |Factors affecting Photosynthesis and |14 | | | | |
| |Cell Respiration | | | | | |
|3.2.F.a |Selectively Permeable Membrane |16 | | | | |
|3.2.F.b |Transmembrane Movement |18 | | | | |
|3.2.F.c |Importance of Water |21 | | | | |
|3.3.B.a |Chemical and Structural Properties of |23 | | | | |
| |DNA | | | | | |
|3.3.B.b |DNA/Proteins/Characteristics |25 | | | | |
|3.3.B.e |Cause and Effects of DNA Mutations |27 | | | | |
|3.3.C.a |Mitosis |29 | | | | |
|3.3.C.b |Meiosis |31 | | | | |
|3.3.C.c |Fertilization |33 | | | | |
|3.3.D.a |Advantages and Disadvantages of |35 | | | | |
| |Asexual/Sexual Reproduction | | | | | |
|3.3.E.a |Genotype leading to Phenotypic Variation|37 | | | | |
|3.3.E.b |Punnett Squares and Genotype/Phenotype |39 | | | | |
| |Probability | | | | | |
|4.1.A.a |Organismal Interactions and Symbiosis |41 | | | | |
|4.1.A.b |Cooperative and Competitive Interactions|44 | | | | |
|4.1.B.a |Biotic and Abiotic Limiting Factors |46 | | | | |
| |Affecting Carrying Capacity | | | | | |
|4.1.D.a |Impact of Environmental Events |48 | | | | |
|4.2.A.c |Flow of Energy in Food Webs |50 | | | | |
|4.3.B.b |Reproduction and Species Survival |53 | | | | |
|4.3.C.a |Adaptation and Variation |55 | | | | |
|4.3.C.c |Environmental Factors and Natural |57 | | | | |
| |Selection | | | | | |
|Common Biology Terms Glossary |59 |
|EOC CRIB SHEET |61 |
How to use this review guide…
This review guide is designed to help you prepare for the Biology End-of-Course Exam (EOC). The Missouri Department of Education has created a list of things you need to learn in Biology called Course Level Expectations (CLE for short). The EOC will test your knowledge of some of these CLEs. This review guide focuses on the chosen, or prioritized, CLEs that are tested on the EOC.
This review guide goes through each CLE tested on the EOC. For each CLE, the key Vocabulary terms are listed and defined. Then, a brief Overview of topic is given. Often drawings or diagrams are included to help you visualize the concept. The CLE is then summarized in the Must Know section that helps you focus in on what you absolutely must remember. Finally, Review Questions are given so that you can quiz yourself and find out how well you know that CLE. Answers to the review questions are available from your teacher. When you have completed all of the review questions for a CLE, your teacher will sign off that CLE in the Review Questions Completed section on the table on the previous page.
Once you have studied, reviewed, and quizzed yourself on a CLE, you can take the EOC Mastery Quiz for that CLE. This quiz has questions on it that are very similar to the End of Course Exam and will give you a good idea of how you will do on the EOC. In order to show that you are “EOC Ready” you need to score an 80% or better on the mastery quiz. Once you have scored an 80% or better on the mastery quiz for a CLE, your teacher will sign off that CLE in the Mastery Quiz Passed section on the table on the previous page.
A Word on “Studying”….
Many students think that studying means looking at your notes or a review guide for five or ten minutes while you are texting a friend, talking to your mom, watching TV, and/or eating a snack. That is NOT studying. Studying means you are actively working hard to memorize and understand the material so well that you can tell anyone about it from memory. If you really understand and know something, the way you need to know and understand the material for the Biology EOC, you will be able to explain it, with all the details and examples, without using your notes or book to someone who has no idea what you are talking about. Think about Mrs. Selimovic and Mr. Coppedge. When you ask them a question about Biology they can almost always explain the answer to you without looking it up. That’s because he studied Biology really hard for a long time. Now, you don’t have to know as much as Mrs. Selimovic or Mr. Coppedge, which is great because we only have weeks until the EOC, not years like they did. BUT, you do need to STUDY (for real-zees) the material in this review guide so you are prepared for the EOC. Here are some easy ways to study…
• Make flashcards for each of the vocabulary terms. Then, quiz yourself on the terms any time you have a few extra minutes at the bus stop/ride, in line at the store, before you go to bed, etc.
• Use the EOC CRIB SHEET (last page of this review packet). You can tear it off and carry it around with you. Read over it again and again and again until you can repeat everything on it back to someone without looking.
• Go over the review questions for 5 different CLEs every day. There are 35 CLEs so that means you will make it through all of the review questions in a week. Keep doing this every week until the EOC.
• Form a study group with people you trust and who you know take learning seriously. Quiz each other by asking them the review questions from this packet and others questions that you come up with on your own.
|3.1.B.a |Recognize cells both increase in number and differentiate, becoming specialized in structure and function, during and after embryonic development |
Key Vocabulary
• Organism- any living thing (ex. Plant, animal, bacteria)
• Differentiation- the process by which cells undergo a change in their structure and function and become a certain type of cell that has specialized function(s)
• Embryo-developing organism from the time the fertilized cell implants in the uterus until the cells noticeable differentiate
Overview
All living things, no matter how big they grow to be, start as just a single cell. Cells have a limited size that they can grow to be and that’s still really, really small. So the only way that an organism can get bigger is by increasing the number of cells. It’s kind of like building a wall. You can’t make bricks bigger so the only way to get a taller, longer wall is to add more bricks. As cells grow, they also become specialized through the process of differentiation. During differentiation, cells change in both their shape/structure and in their function (the job they do). Having cells that do different jobs allows the organism to have many different processes, reactions, and actions taking place all at the same time. The production of new cells and the differentiation of these cells occur both during embryonic development (what we call pregnancy in mammals like humans) as well as after. Below is a diagram showing the differentiation of cells into all the different types of cells that make up bones.
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Must Know
• Cells are the smallest living thing and are referred to as the building blocks of life because they make up all other living things.
• Organisms increase in size by increasing their number of cells
• Cells differentiate into different types of cells so that many different reactions can occur at the same time
• Cell formation and differentiation occurs both during and after embryonic development.
Review Questions
1. How does an organism increase its size?
a. It produces more cells c. It increases the number of cells and the size of those cells
b. Its cells grow larger d. The number of cells increases while the size of each cell decreases.
1. Which of the following most accurately describe the result of cell division without differentiation?
a. The organism increases in size, but has only the simplest functions occurring within it
b. The organism has more complex reactions occurring within it but remains constant in size
c. The organism has both increased size and reaction/process complexity
d. The organism will perform only the simplest of reactions while also decreasing in size
2. What is cellular differentiation?
a. The selection by scientists of certain types of cells for certain drugs
b. The changes in the structure and function of a cell to become a certain type of cell
c. The growth of cells in size
d. The ability of the body to change cells from one type to another depending on the body’s need at any particular time
3. Which of the following best explains how growth in wallabies occurs?
a. Female wallabies donate a large number of their own cells to form the baby wallaby.
b. Male and female wallabies both donate large numbers of their own cells to form baby wallabies.
c. The single cell formed by the fusion of a sperm and an egg divides and each of those cells divide and then those cells divide (and so on) increasing the number of cells in the developing wallaby
d. Wallabies are born with all of the cells they need for their lives. They grow in body size by increasing the size of those cells through the consumption of nutrients.
4. Why is cellular differentiation important?
a. It allows the organism to increase the size of its cells
b. It allows the organism to regulate the size that it grows to
c. It allows simple functions to occur simultaneously inside of an organism
d. It allows complicated functions to occur simultaneously inside of an organism
5. Which of the following is an example of cellular differentiation?
a. The different types of tissues found in humans (brain, heart, lung, stomach, etc)
b. The large size of an elephant
c. The fact that elephant and mouse cells are similar in size
d. The fact that all bacteria cells in a colony are almost identical
6. Which of the following is an example of cell differentiation?
a. Epidermal cells dividing to form more epidermal cells
b. Epithelial cells dividing to form parenchymal cells which in turn divide to form cells of the endocrine and exocrine systems
c. Parietal cells producing hydrochloric acid to aid in food digestion
d. Epithelial cells undergoing apoptosis once they have reached the end of their lifespan
7. Which of the following would most likely result in certain death for a multi-celled organism?
a. An increase in nutrients
b. A decrease in disease
c. An inability to undergo further cell division
d. A limit on cell sized based on nutrient requirements of cells
8. When does cellular division occur?
a. Only before an organism is done with embryonic (before birth) development
b. Only after an organism is done with embryonic development
c. Mainly after the embryonic stage of an organism, but some during
d. Throughout the entire lifetime of that organism
|3.1.C.b |Describe the structure of cell parts (e.g., cell wall, cell membrane, cytoplasm, nucleus, chloroplast, mitochondrion, ribosome, vacuole) found in |
| |different types of cells (e.g., bacterial, plant, skin, nerve, blood, muscle) and the functions they perform (e.g., structural support, transport of |
| |materials, storage of genetic information, photosynthesis and respiration, synthesis of new molecules, waste disposal) that are necessary to the |
| |survival of the cell and organism |
Key Vocabulary
• Organelle- membrane-bound structure that is specialized to perform a certain job in the cell
• Cell Wall- only in PLANT cells. Rigid structure that gives support, protection, and shape
• Cell Membrane- phospholipids membrane surrounding a cell. Controls what can enter and exit the cell
• Cytoplasm- jelly-like substance found inside cells. Organelles are suspended in it.
• Nucleus- organelle that contains a cell’s DNA and controls/regulates the processes inside the cell
• Chloroplast- only in PLANT cells. Site of photosynthesis. Converts energy from the sun into chemical energy.
• Mitochondrion (plural: mitochondria)- organelle that supplies energy for the cell. Site of cell respiration
• Ribosome- organelle that connects amino acids to make proteins
• Vacuole- organelle that stores materials needed by the cell. Larger in plants where they hold lots of water
• Lysosomes- organelle that contains enzymes that break down dead/damaged cell parts (Cell Lysol)
• Endoplasmic Reticulum- network of membranes that processes, activates, and distributes proteins
• Golgi Bodies (aka Golgi Apparatus)- stacked membrane organelles that package and deliver proteins (UPS/Postal Service of cell)
Overview
All organisms are made up of cells. Some organisms may be just one cell while others may have hundreds of trillions of cells. There are two categories of cells. Prokaryotic cells are less complex and are found in single-celled organisms. Eukaryotic cells are much more complex and make up organisms with many cells.
Organelles are small structures that make up cells. Organelles are surrounded by their own membranes. Because they are separated from each other, each organelle can have its own processes occurring without affecting the others. This allows a cell to have many complex reactions and processes occurring all at the same time. Each organelle has a specific job or role that is necessary for the cell to survive.
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Must Know
• Name and function of each organelle defined above and locate it in a diagram
• Organelles work together to make a cell function, but are not consider living by themselves
Review Questions
1. Plant cells have an additional structure beyond their plasma cell membranes that animal cells lack. One function of this additional structure is to
a. perform active transport. c. enable the cell to undergo phagocytosis.
b. provide structure and protection. d. trap sunlight in order to convert it to energy.
2. In animal cells, the endoplasmic reticulum serves as a channel for the transport of materials through the cell. The outer surface of the endoplasmic reticulum may be smooth or rough. Which cell structures, which build proteins cause the outer surface of endoplasmic reticulum to appear rough?
a. The ribosomes b. The transport protein c. The mitochondria d. The Golgi body
3. Many complex reactions are occurring simultaneously in cells and these reactions must be regulated. Which structure is primarily responsible for directing all processes and reactions in a plant cell?
a. Chloroplasts b. Lysosome c. Mitochondria d. Nucleus
4. Because plants lack the internal structural support of bones like many animals have, the support and structure in plants comes primarily from the
a. Cell wall b. Cell membrane c. Nucleus d. Ribosome
5. Proteins play a vital role in creating channels through which material can move into and out of the cell. Which of the following organelles produces the proteins in the membrane of the endoplasmic reticulum and in other places around the cell?
a. Mitochondria b. Ribosomes c. Nucleus d. Vacuoles
6. If an analogy were to be made between the function of different cell organelles and the services provided by different companies, which organelle might be considered the FedEx of the cell?
a. Mitochondria b. Endoplasmic Reticulum c. Golgi Bodies d. Cell Wall
7. Plant cells are classified as producers because they are able to utilize non-organic (not from living things) energy such as sunlight and heat to produce energy stored in molecules that living organisms can use. Plants also use the energy they produce to power the functions of their cells. Which pair of organelles below are responsible for these functions within a cell?
a. Golgi Bodies and Lysosomes c. Vacuoles and Cell Wall
b. Mitochondria and Cytoplasm d. Chloroplasts and Mitochondria
8. Because of the large number of molecules moving into and out of the cell and the numerous processes occurring within it, excess waste and non-functioning cellular components can build up in the cytoplasm. Which organelle is primarily tasked with providing clean up services for the cell?
a. Golgi Bodies b. Lysosomes c. Vacuoles d. Ribosomes
9. DNA is the chemical molecule that contains all of the genetic information that directs the formation of the structure and regulates the functions of cells. In which organelle is DNA found?
a. Nucleus b. Lysosomes c. Cell Membrane d. Endoplasmic Reticulum
10. The cell lacks internal support structure that the skeletal system provides in humans. Instead, molecules and organelles are suspended in a jelly-like substance known as the
a. Nucleus b. Ribosomes c. Chloroplasts d. Cytoplasm
11. Plant cells have a complex series of reactions occurring in them that capture sunlight and convert that light energy into chemical energy. These reactions occurring in which of the following organelles and is unique to plant cells?
a. Cytoplasm b. Mitochondria c. Chloroplasts d. Ribosomes
12. Muscle cells demand a large amount of energy to keep functioning, especially muscles cells that are constantly contracting like the muscle cells that make up the heart. Muscle cells that have a high-energy demand also have a greater number of mitochondria in them. What reaction is occurring inside these mitochondria?
a. Lipid Production b. ATP Production c. Protein Synthesis d. Cellular Contro
| |Explain physical and chemical interactions that occur between organelles (e.g. nucleus, cell membrane, chloroplast, mitochondrion, ribosome) as they |
|3.2.A.c |carry out life processes |
Key Vocabulary
• Interaction- Two or more things that have an affect of each other
Overview
Each organelle within a cell has a specific role or job. However, what occurs in one organelle affects, or is affected by, what is occurring in another cell. There are many interactions between two or more organelles that allow cells to function properly.
One such interaction is the between the nucleus, ribosomes, and endoplasmic reticulum of a cell. DNA within the nucleus directs the ribosomes to make certain proteins. Those proteins leave the ribosomes and go to the endoplasmic reticulum. The endoplasmic reticulum folds the proteins into their active shape and then distribute the proteins throughout the cell.
A second interaction would be the interrelated functions of chloroplasts and mitochondria. See CLE 3.2.B.a for thorough description of this interaction.
The cell membrane directly impacts the functions of all organelles since it regulates what can enter and exit the cell, therefore regulating what molecules are available to each organelle and allowing the products and wastes generated by organelles to exit the cell.
Must Know
• DNA (nucleus) ( RNA ( Protein (ribosome) ( Protein Folding (Endoplasmic Reticulum)( Traits
• Photosynthesis (chloroplasts) ( Cell Respiration (mitochondria)
Review Questions
1. Which is an organelle that performs cellular respiration and is paired with its correct function?
a. chloroplast- converts light energy into chemical energy
b. chloroplast- converts chemical energy into light energy
c. mitochondrion- converts energy found in glucose into energy for use by the cell
d. mitochondrion- converts cellular energy into glucose chemical energy
2. Glucose produced by chloroplasts is used by which of the following structures?
a. Nucleus b. Mitochondria c. Cell Membrane d. Cell Wall
3. Proteins made within the ribosomes & endoplasmic reticulum are packaged & shipped out of the cell by the:
a. Nucleus b. Golgi Bodies c. Cell wall d. Cytoskeleton
4. In the cell membrane there are special tubes that pump large molecules into the cell. These pumps
require ATP in order to work. From which structure will these proteins get their ATP?
a. Cytoskeleton b. Golgi Bodies c. Chloroplasts d. Mitochondria
5. The following cell structures are located within cells that make proteins.
• Nucleus
• Ribosome
• Endoplasmic Reticulum (ER)
Which description best explains the relationship among these cell structures in making a protein?
a. Nucleus makes protein ( protein winds through the ER ( protein folds into its active shape
b. Nucleus directs ER to assemble the protein ( ribosomes surround protein ( protein folds into its active shape.
c. ER creates proteins ( DNA in the nucleus codes for ribosomes to surround protein ( protein folds into its active shape
d. DNA in nucleus codes for protein ( protein assembled in ribosomes and moves to ER ( protein folds into its active shape in the ER
|3.2.B.a |Explain the interrelationship between the processes of photosynthesis and cellular respiration (e.g., recycling of oxygen and carbon dioxide), |
| |comparing and contrasting photosynthesis and cellular respiration reactions (Do NOT assess intermediate reactions) |
Key Vocabulary
• Products- Chemicals/molecules that are formed/made during a reaction
• Reactants- Chemicals/molecules that are used up during a reaction (ingredients)
• Photosynthesis- Reaction occurring in chloroplasts that uses sunlight to turn carbon dioxide and water into sugar (glucose) and oxygen
• Cellular Respiration- Reaction occurring in mitochondria that turns sugar (glucose) and oxygen into ATP, carbon dioxide and water.
• Mitochondria- Organelle found in both plant and animal cells and is the location of cell respiration.
• Chloroplasts- Organelle found only in plant cells and is the location of photosynthesis
• Sugar (Glucose)- molecule composed of carbon, oxygen, and hydrogen
• Carbon Dioxide- molecules composed of one carbon molecule and two oxygen molecules
Overview
One of the most important interactions in cells is the one between mitochondria and chloroplasts. Mitochondria are found in all cells. Cell respiration occurs inside of mitochondria. The Chloroplast is found only in plant cells and is the location of photosynthesis.
Both cell respiration and photosynthesis are chemical reactions that have multiple reactants and products and molecules that shared between the reactions. It is important to keep straight which role each molecule is playing in a certain reaction.
In photosynthesis, sun activates a reaction between carbon dioxide and water (reactants). This reaction produces sugar and oxygen. This sugar and oxygen is either used by the plant or released into the air (carbon dioxide) and consumed by another organism (sugar).
In cell respiration, the sugar and oxygen produced by photosynthesis enters the mitochondria. Inside the mitochondria, a reaction occurs and the sugar and oxygen are converted in ATP, carbon dioxide, and water. The carbon dioxide is released to the environment where it is take up by plants and used in photosynthesis. ATP is used by the cell to power all of its functions.
Important Chemical Reactions
Photosynthesis
Sunlight + 6 CO2 + 6 H2O -> C6H1206 + 6 O2
Cell Respiration
C6H1206 + 6 O2 -> 6 CO2 + 6 H2O + 36 ATP
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Must Know
• Photosynthesis uses sunlight, carbon dioxide, and water and produces oxygen and sugar (only in plants)
• Cell Respiration uses oxygen and sugar and produces carbon dioxide, water and ATP (occurs in plants and animals)
• The products of Photosynthesis are the reactants of Cell Respiration and some of the products of Cell Respiration are reactants in Photosynthesis. Both Oxygen and Carbon Dioxide are recycled in the combined processes of Photosynthesis and Cell Respiration.
Review Questions
1. Which of the following correctly explains how carbon in our bodies moves through the environment?
a. Carbon is released from our bodies in the form of carbon dioxide. The carbon dioxide is taken up by plants which covert it to sugars. Other organisms, like humans, eat the plants and convert the sugars into energy and carbon dioxide.
b. Carbon is only released when our bodies are decomposed by microorganisms.
c. Carbon is taken up by our bodies and released as oxygen. Oxygen is then taken up by plants, converted into carbon dioxide. The plants release the carbon dioxide which is then absorbed by humans to produce energy.
d. Carbon cannot move through the environment since it is only found in humans.
1. Why is it necessary for both photosynthesis and cell respiration to occur simultaneously?
a. The products of photosynthesis are the reactants of cell respiration and visa versa.
b. The products of photosynthesis and cell respiration combine to form gases necessary for sustaining life on earth.
c. Both reactions produce oxygen, which results in the correct levels of oxygen for survival.
d. Both reactions eliminate carbon dioxide thus reducing global warming gases.
2. How do plants contribute to the carbon cycle?
a. Plants are necessary for converting sugars into large amounts of carbon dioxide.
b. Plants are necessary for using energy from the sun to convert carbon from carbon dioxide into a form (sugars) that usable by other organisms.
c. Plants increase the amount of carbon dioxide, there by reducing the need for oxygen.
d. Plants prevent the carbon cycle from being disrupted by decreasing the amount of sunlight
3. Which of following best explains how plants and animals exchange gases with their environment?
a. Plants make oxygen while animals produce carbon dioxide that is used by plants
b. Animals make oxygen used by plants and plants make carbon dioxide used by animals
c. Plants capture oxygen and produce carbon dioxide while animals use oxygen as well.
d. Plants produce carbon dioxide that mixes with glucose produced by animals.
4. What process removes carbon dioxide from the atmosphere?
a. Cell Respiration b. Decomposition c. Assimilation d. Photosynthesis
5. Which of these best explains the difference between the way animals and plants exchange gases with their environment?
a. Animals use only photosynthesis, while plants use both photosynthesis and respiration.
b. Animals use only respiration, while plants use both photosynthesis and respiration.
c. Animals use both photosynthesis and respiration, while plants use only respiration.
d. Animals use both photosynthesis and respiration, while plants only use photosynthesis.
6. A plant is placed in a sealed chamber and the chamber is filled with air that has the normal mix of atmospheric gases. Which of the following would accurately describe the concentration of carbon dioxide and oxygen for the several days following the chamber being sealed?
a. The concentration of carbon dioxide would increase while the concentration of oxygen would decrease
b. The concentrations of both carbon dioxide and oxygen would decrease
c. The concentration of oxygen would increase while the concentration of carbon dioxide would increase
d. The concentrations of both carbon dioxide and oxygen would increase
7. Which of the following will contribute the atmospheric levels of carbon dioxide?
Cell Respiration b. Electrophoresis c. Photosynthesis d. Protein Synthesis
8. Plants are an ideal model of the relationship between photosynthesis and cellular respiration since both reactions occur within each plant cell. Which of the follow accurately describes how these two reactions interact inside of a plant cell?
a. Sugars and oxygen produced by photosynthesis in chloroplasts is used by mitochondria, which also produces glucose and oxygen.
b. Carbon Dioxide and water produced by cell respiration inside mitochondria is used by photosynthesis in chloroplasts to make carbohydrates (sugars) and oxygen.
c. Proteins made by photosynthesis in chloroplasts are used to make oxygen and sugar by cell respiration inside mitochondria.
d. Water and carbohydrates are produced by photosynthesis and used by cellular respiration to make oxygen and carbon dioxide before being shipped to the mitochondria.
|3.2.B.b |Determine what factors affect the processes of photosynthesis and cellular respiration (i.e., light intensity, availability of reactants, temperature)|
Key Vocabulary
• Temperature- How much heat is in a given area or object
• Humidity- amount of water molecules in the air
• Concentration- the amount of a certain type of molecule in a substance compared to the total amount of the substance
• Light Intensity- power or brightness of a light
Overview
Because cell respiration and photosynthesis are interrelated, a change in one reaction will eventually affect the other. Within certain limits, an increase in photosynthesis will lead to an increase in cell respiration and vise versa. Likewise, a decrease in cell respiration may lead to a decrease in photosynthesis.
Other factors affecting photosynthesis and respiration include the availability of the reactants. Increases in temperature, water (including in the air), light intensity, nutrient availability and the concentration of gases (oxygen and carbon dioxide) will lead to increases in which ever reaction requires them as a product. However, there is a limit, that once reached, more of the reactants with either have no effect or may begin to have a negative affect (i.e. if sun intensity increases too much, the plant will be burned).
Must Know
• The availability of light, water, carbon dioxide, and oxygen affects photosynthesis and cell respiration.
• Generally an increase in water, light, and carbon dioxide will increase the rate of photosynthesis
• An increase in organic molecules (sugar) and oxygen will increase the rate of cell respiration
Review Questions
Use the description to answer the questions.
Deforestation is the result of the removal of trees and large brush from forested areas resulting in large areas that are completely without trees. Deforestation is often the result of cutting trees to make wood and paper products or clearing trees to make open areas suitable for farmland. Deforestation results in the loss of many plant and animal species. It also results in the sun shining directly on the soil, which can dry it out, and the soil having a higher exposure to rain and wind resulting in higher rates of erosion.
1. What impact would deforestation have on the availability of gases for other organisms?
a. Deforestation would have not impact on the availability of other gases.
b. Deforestation would result in an increase in oxygen levels
c. Deforestation would result in a decrease in oxygen levels and an increase in CO2 levels.
d. Deforestation would result in a stabilizing of both oxygen and carbon dioxide levels
2. How might the lack of trees affect small vegetation found on the forest floor?
a. Without trees, more sunlight reaches the forest floor resulting in higher rates of photosynthesis in small plants found there
b. Deforestation would have no impact on vegetation on the forest floor.
c. Deforestation would result in higher levels of oxygen being available of forest floor plants
d. Deforestation would result in lower levels of carbon dioxide near the forest floor.
3. What is the likely result if the area that has been deforested also experiences a drought?
a. The atmosphere concentration of oxygen would increase.
b. The atmosphere concentration of carbon dioxide would increase
c. The rate of photosynthesis would increase
d. The rate of cellular respiration would increase.
4. How might deforestation contribute to global climate change (which is the increase of carbon dioxide in the atmosphere)?
a. Deforestation would result in less photosynthesis occurring. This results in less CO2 being used up thereby increasing atmosphere levels of carbon dioxide.
b. Deforestation would result in increased usage of oxygen which results in more carbon dioxide
c. Deforestation has no impact on CO2 and therefore no impact on global climate change
d. Deforestation results in an increase in photosynthesis, resulting in higher levels of CO2
5. Dewayne went camping. It rained & got all of his gear wet. When he got home, he stretched the tent out in his yard to dry in the sun. He got busy & left it there for a couple of days. When he folded up the end he noticed that the grass had turned yellow& looked like it was drying. What might have caused the grass to start to die?
a. The tent smothered the grass and prevented any carbon dioxide from getting to it.
b. The tent trapped the oxygen next to the grass and since plants can’t use O2, they die.
c. The tent prevents sunlight from reaching the grass. This cuts down on the amount of photosynthesis occurring resulting in less O2 and sugars available for the plant to use for survival
d. The tent traps moisture against the grass and causes the grass to begin to drown.
6. Which of these would lead to a lower rate of cellular respiration in a plant?
a. An increase in the amount of oxygen in the air
b. A decrease in the amount of oxygen in the air
c. An increase in the amount of carbon dioxide in the air
d. A decrease in the amount of carbon dioxide in the air
7. How would a drop in temperature most likely affect the process of cellular respiration and photosynthesis?
a. The rates of both cellular respiration and photosynthesis would decrease
b. The rates of both cellular respiration and photosynthesis would remain constant
c. The rate of photosynthesis would increase and the rate of cellular respiration would decrease
d. The rate of photosynthesis would decrease and the rate of cellular respiration would increase.
8. Which of the following best describes what happens first when the amount of sunlight decreases?
a. The rates of both cellular respiration and photosynthesis would decrease
b. The rates of both cellular respiration and photosynthesis would remain constant
c. The rate of photosynthesis would increase and the rate of cellular respiration would decrease.
d. The rate of photosynthesis would decrease and the rate of cellular respiration would remain constant.
9. Four plants are each placed inside a different sealed glass chamber. Each plant receives the same amount and type of fertilizer, soil, water, and sunlight. Two of the chambers have extra carbon dioxide pumped into them while the other two have normal air pumped into them. Which of the following results would be expected to be observed first?
a. An increase in photosynthesis in the plants receiving normal air.
b. A decrease in photosynthesis in the plants receiving normal air.
c. An increase in photosynthesis in the plants receiving air with elevated carbon dioxide levels
d. A decrease in photosynthesis in the plants receiving air with elevated carbon dioxide levels
|3.2.F.a |Explain the significance of the selectively permeable membrane to the transport of molecules |
Key Vocabulary
• Membrane- barrier/divider between two areas
• Molecule- a group of two or more atoms held together by bonds
• Permeable- Almost any type of molecule can cross through
• Selectively (semi-) permeable- only certain molecules are allowed to cross/pass
• Impermeable- no molecules are allowed to cross/pass
Overview
Membranes are vital to the survival of organisms as they allow all levels of an organism (organelle, cell, tissue, and organ levels) to separate areas to keep reactions, substances, and process from interfering with one another. The primary purpose of a membrane is to regulate what molecules may enter or exit a particular area.
A membrane is said to be permeable if it allows molecules to cross it (go through it). If no molecules are able to cross a membrane is it call impermeable. Semi (or selectively) permeable membranes, such as cell membranes, allow some molecules to cross while preventing other molecules from crossing. This helps regulate what is available to the various reactions occurring in the cell.
Inside of, going through, and connected to the membrane are other molecules including proteins and carbohydrates. These molecules help support the membrane as well as provide channels and pumps that help move molecules across the membrane.
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Must Know
• Cell membranes are phospholipids bilayers.
• A cell membrane is semi- or selectively permeable, which means that it regulates which molecules can go through it. This allows cells to maintain different conditions inside of the cell compared to the conditions surrounding the cell.
Review Questions
1. What is the main function of a selectively permeable (semipermeable) cell membrane?
a. Storage of water c. Break down molecules within the cell
b. Storage of chemicals d. Regulate what enters and leaves the cell
2. Why are semi- or selectively permeable membranes important?
a. They allow only certain materials to cross the membrane
b. They allow all materials to cross into and out of the cell freely
c. They prevent dangerous chemicals of any kind from entering the cell and prevent anything from leaving the cell
d. They keep all material from entering or leaving the cell.
3. If a cell membrane was impermeable instead of selectively permeable, which of the following would most likely happen to a cell?
a. The cell would continue to function normally.
b. The cell would have an increased chance of survival since there would be no chance of potential harmful compounds entering the cell.
c. The cell would have a decreased chance of survival since waste CO2 would build up in the cell and the amount of carbohydrates and O2 in the cell would decrease.
d. A prediction is not possible based on the information presented.
4. Which of the following is an example of a semipermeable membrane?
a. Waterproof wrapping for a house b. Cell membrane c. Glass window d. Both b & c
5. The cell membrane of red blood cells will allow water, oxygen, carbon dioxide and glucose to pass through. Because other substances are blocked from entering, this membrane is called
a. Perforated b. Semipermeable c. Permeable d. Non-conductive
6. A bag is filled with blue food coloring, water, and starch and then sealed. The bag is placed into a jar of normal tap water. After 24 hours of soaking, the water in the jar is now a blue color. However, tests on the water indicate that there is no starch in the water. Which of the following best explains the results of this experiment?
a. The bag acted as an impermeable membrane because it prevented any molecules from entering or leaving the bag.
b. The bag acted as a semipermeable membrane because it allowed certain molecules to pass through its walls while preventing other molecules from crossing
c. The bag acted as a permeable membrane because it allowed molecules to cross through its walls
d. The bag acted as a semipermeable membrane by allowing molecules to pass freely into and out of the bag.
7. Why are semipermeable membranes necessary for a cell to survive?
a. They allow nutrients to enter the cell and products and waste to leave
b. They keep all material from entering the cell.
c. They allow the concentration of solutions inside the cell to be the same as the solution surrounding the cell
d. They make it possible for material to move freely into and out of the cell
|3.2.F.b |Predict the movement of molecules across a selectively permeable membrane (i.e., diffusion, osmosis, active transport) needed for a cell to maintain |
| |homeostasis given concentration gradients and different sizes of molecules |
Key Vocabulary
• Homeostasis-maintenance of constant, internal conditions in an organism
• Concentration gradient- Concentration of a molecule is higher in one area than in another
• Diffusion- Molecules move from an area of higher concentration to an area of lower concentration
• Osmosis- Water molecules move across a membrane from an area of high water concentration to an area of low water concentration
• Active Transport- transport of molecules across a membrane that requires energy
• Passive Transport- transport of molecules across a membrane that does not require energy
Overview
Homeostasis is when an organism maintains constant conditions inside the body. If the conditions change, the organism will respond to bring things back to the normal status. Examples of homeostasis include body temperature, blood sugar, and blood pressure. Many reactions and processes in our bodies require a certain concentration of molecules. Changes in the concentration of these molecules can result in a change in homeostasis.
The movement of molecules across a membrane sometimes requires energy. When energy is required for transporting molecules it is called active transport. Large molecules that can’t fit through the membrane or molecules that are trying to go against the concentration gradient are moved by active transport. Movement of smaller molecules or movement along the concentration gradient do not require energy and therefore considered to be passive transport. As an analogy, active transport is like swimming up a river. You have to use a lot of energy to go against the current. Passive transport is like floating down a river. You don’t have to use any energy you just passively “go with the flow”.
Think of a concentration gradient as like a slide. It is easy (passive) to go along with the concentration gradient or down the slide. Going back up the slide or going against the concentration gradient, requires energy (active).
Diffusion is one way that the concentration of molecules can remain balanced. Diffusion is a form of passive transportation and is the movement of molecules besides water. Diffusing molecules move along a concentration gradient which means they move from an area of high molecule concentration to an area of low concentration.
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Osmosis is one way that amount of water in and around cells remains balanced and is a type of passive transport. Osmosis is the movement of water from an area of high water concentration to an area of low water concentration. You must remember that concentrations represent how much of a solution is made up of a certain molecule. For example, a 30% NaCl solution means that the solution is 30% NaCl and 70% water. Most of the time, you will need to figure out what the concentration of water is before determining where the water molecules will move.
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Must Know
• Concentration refers to how much of a substance is in a solution
• Passive Transport is the movement of molecules along a concentration gradient (toward a lower concentration)
• Diffusion is the movement of molecules (besides water) to an area of lower concentration
• Osmosis is the movement of water toward an area of lower water concentration
Review Questions
1. A cell requires energy to move materials from an area of low concentration, across the cell membrane, to an area of high concentration. This process is called:
a. Osmosis b. Active Transport c. Diffusion d. Facilitated Diffusion
2. The diagram below shows a semipermeable membrane (like that of a cell) dividing tow containers and the concentration of solutions on either side of the membrane.
Which of the following best describes how the molecules will move?
a. Water molecules will move from side A to side B. c. NaCl will move from side B to side A
b. Water molecules will move from side B to side A. d. NaCl will move from side A to side B
3. A molecule can easily pass through the selectively permeable membrane of an animal cell. Which of these most likely describes the molecule.
a. The molecule is very small and charged c. The molecule is very small and not charged
b. The molecule is very large and charged d. The molecule is very large and not charged
4. While cleaning a saltwater aquarium, students placed the aquarium plants (which have salt water in their cells) in a container of distilled water (water with no salt in it). What effect will this have on the plants?
a. The plant cells will separate c. The plant cells will swell
b. The plant cells will shrink d. The plant cells will remain the same
5. What will happen if an animal cell that has a salt concentration of 1% is placed in a 25% saltwater solution?
a. It will shrink because water moves toward areas of higher solute concentration.
b. It will burst because water moves toward areas of higher solute concentration.
c. It will burst because water moves toward areas of lower solute concentration.
d. It will shrink because water moves toward areas of lower solute concentration.
6. While eating grapes, Quandria thought the skin of the grape probably acted similarly to a cell membrane. She decided to test this out. She found the mass of three grapes. She then soaked each grape in a different solution for 24 hours. She then dried the grapes and reweighed them. She recorded the results of her experiment in the table below:
| |Grape Soaked in Water |Grape Soaked in Grape Juice |Grape Soaked in Sugar Water |
|Mass Before Soaking |10.5g |9.9 g |10.2g |
|Mass After Soaking |11.4g |9.8 g |7.4g |
Which of the following best explains the results of this experiment?
a. The masses of the grapes changed as a result of water following its concentration gradient
b. The masses of the grapes changed as a result of sugar following its concentration gradient
c. The masses of the grapes changed due to water undergoing diffusion
d. The masses of the grapes changed due to sugar undergoing osmosis
7. In the lungs, the movement of oxygen into blood (low oxygen concentration) from the air (high oxygen concentration) can best be explained by which of the following processes?
a. Active Transport b. Diffusion c. Endocytosis d. Osmosis
8. Which molecule would be least likely to diffuse across the phospholipids bilayer of a cell membrane?
a. Large molecules such as Glucose c. Sodium Ions (Sodium with a positive charge)
b. Small non-polar molecules like Oxygen d. Sodium Bicarbonate
|3.2.F.c |Explain how water is important to cells (e.g., is a buffer for body temperature, provides soluble environment for chemical reactions, serves as a |
| |reactant in chemical reactions, provides hydration that maintains cell turgidity, maintains protein shape) |
Key Vocabulary
• Turgidity-pressure on cell wall from the water within the cell. Higher turgidity means firmer cells.
• Fresh Water- water that has a salt concentration of less than 1%
Overview
Water is really important to all living organisms. Without fresh, liquid water, life would not be able to exist on earth.
One way that water is necessary for life is that it provides support within our cells. Just like a water balloon doesn’t compress as much as a balloon filled with air, the water in our cells keeps the cells firm yet flexible. Scientists describe this firmness as turgidity. Because of its density, water also creates pressure that helps molecules retain their shape. The pressure on proteins dissolved in water helps the proteins keep their shape.
Another way that water is important is that it can absorb and release a large quantity of heat. This helps regulate your body’s temperature as the water evaporates to cool you off when you are hot or is retained to help insulate you in the cold.
Because of the properties of the atoms that make up water and the characteristics of the bonds between them, many molecules can be dissolved in water. Because of this, water serves as a molecule “metro” carrying molecules of all kinds throughout organisms (remember that the blood carrying substances throughout your body is 90% water and that plants require water to move nutrients up through their stems and leaves). It also allows water to be an idea environment for chemical reactions to occur in.Water itself can also serve as a reactant and play a role in the reaction (such as in photosynthesis).
Must Know
• Fresh, liquid is necessary for life.
• Water provides support, temperature regulation, molecule transport, and an environment for reactions and acts as a reactant.
Review Questions
1. How does the presence of water in cells affect the temperature of the human body?
a. It moderates/regulates the body temperature c. It decreases the body temperature
b. It increases the body temperature d. It has no affect on body temperature
2. Which of the following accurately describes what happens to cells that do not have enough water in/available to them?
a. They become thirty
b. Important chemical Reactions may not occur correctly.
c. The cell membrane may become less firm and the cell may shrink in size.
d. Both B and C.
3. Why is water important to cells?
a. All proteins are made up of water
b. The main component of DNA is water
c. Water creates an acidic environment in cells
d. Water serves as a reactant in many chemical reactions and helps the cell remain firm and strong
4. Water is very important to cells because of the type of molecule that it is. Which of the following highlights one reason why water is important to cells?
a. Water washes the inside of the cell.
b. Many different types of materials can dissolve in water, which makes it easier to move materials around and into/out of the cell.
c. Water boils at a high temperature, so cells aren’t damaged by heat.
d. Water removes impurities from the genetic code of cells,which keeps mutations from forming.
5. How are the cells of organisms affected differently by substances that easily mix into water than by substances that do not mix easily into water?
a. Substances that cannot mix into water are harmful to cells.
b. Substances that cannot mix into water do not store any energy for cells
c. Substances that can mix into water can be delivered to cells through the blood
d. Substances that can mix into water can help cells release heat through evaporation.
6. Fresh carrots are firm and crunchy. However, carrots that have been left in the refrigerator for a while start to become flexible and can be squeezed slightly. Which of the following best describes the changed in carrots?
a. As water from the air enters the carrots, the extra water makes them soggy.
b. The cold air causes carrots to shrink and they become more flexible
c. The change in temperature from the warmer ground to the cold frig causes changes to the carrots
d. The carrots begin to dry out and the loss of water causes the carrot cells to become less firm
7. Which of the following correctly describes how water helps regulate body temperature?
a. Water can absorb heat when we are hot and helps insulate our bodies when we are cold
b. Water generates heat by moving through our cells
c. Water absorbs heat when we are cold and holds heat in when we are hot.
d. Water does not play a role in regulating body temperature.
|3.3.B.a |Describe the chemical and structural properties of DNA (e.g., DNA is a large polymer formed from linked subunits of four kinds of nitrogen bases; |
| |genetic information is encoded in genes based on the sequence of subunits; each DNA molecule in a cell forms a single chromosome) (Assess the concepts|
| |– NOT memorization of nitrogen base pairs) |
Key Vocabulary
• DNA- DeoxyriboNucleic Acid. Molecule found in all organisms that stores genetic information
• Nitrogen Base- nitrogen-containing molecules found in DNA
• Phosphate Sugar Backbone- structural support of DNA to which nitrogen bases bond
• Nucleotide- molecule made of a phosphate, a sugar, and a nitrogen base linked together
• Chromosome- long strand of DNA that has been tightly coiled up forming a compact bundle of DNA
Overview
DNA (DeoxyriboNucleic Acid) is a long strand made up of smaller molecules joined together. Phosphate and sugar molecules join together to form the backbones of DNA. Nitrogen bases bond with the backbone on one side and another nitrogen base on the other, thereby connecting two backbones together. The tension on the molecules caused by the bonds between them results in the whole strand twisting. This pulling on molecules gives DNA the “twisted ladder” shape that is called a double helix.
[pic] [pic]
A nitrogen base paired with a sugar and a phosphate molecule forms a nucleotide and there are only four types of nucleotides in DNA. The order of the nucleotides determines what information is being carried by the DNA (just like the order of the letters in this sentence determines what words are being formed) and therefore, different orders of nucleotides result in different information being carried.
Must Know
• The DNA in every cell of an organism is identical to the DNA in every other cell.
• DNA is made up of four different nucleotides linked together to form a long, double-stranded molecule.
• Nucleotides are made of nitrogen bases bonded to phosphate sugar molecules.
• As the molecule twists and turns on itself, it coils up to form a chromosome.
• The order of the nucleotides determines what information is being carried by that segment of DNA.
Review Questions
1. Tissue samples taken from the heart and stomach of a grasshopper would be expected to have the same
a. Cell size and shape
b. Metabolic rates
c. Number of mitochondria
d. DNA
2. What is the most accurate statement about the molecule presented below?
[pic]
a. It represents a basic structure of the units that make up DNA
b. A strand of DNA is composed of 4 versions of this molecule
c. It represents the structure of a nucleotide
d. All of the above
3. The chromosome structure of a cell accounts for genetic variation based on the order of its:
a. Sugar Groups
b. Nitrogen Bases
c. Hydrogen Bonds
d. Phosphate Groups
4. The twisted shape of a double helix molecule results from
a. The tension on the bonds between molecules
b. The phosphate molecules have a rounded shape
c. The unequal lengths of the two phosphate sugar backbones
d. A specific order of nucleotides being present
5. How many different nucleotides are used to make DNA?
a. 2
b. 4
c. 23
d. 46
6. Which of the following are true about DNA?
a. Contains the genetic instructions used in the development and functioning of all known organisms
b. Often compared to a set of blueprints, or a recipe, or a code
c. Is a long term storage of genetic information
d. All of the above
7. The order of ________________ making up DNA determines what information is stored on there
a. Sugar groups
b. Nitrogen bases (nucleotides)
c. Hydrogen groups
d. Phosphate groups
8. Which of the following accurately describes the structure of DNA?
a. DNA has sugar bases hydrogen bonded to phosphate molecules.
b. DNA is composed of phosphate sugar backbones connected by nitrogen bases
c. DNA is composed of nitrogen-phosphate backbones connected by sugar bases
d. DNA is composed of nitrogen-sugar backbones connected by phosphate bases with hydrogen bonds.
|3.3.B.b |Recognize that DNA codes for proteins, which are expressed as the heritable characteristics of an organism |
Key Vocabulary
• Protein- molecule made of amino acids linked together
• Trait- characteristic that is heritable (ex. eye color, ear lobe attachment)
• Heritable- a trait that passes from the parents to the offspring by DNA
Overview
DNA is often referred to as a blueprint for the body. This can be a helpful analogy. DNA itself doesn’t form the structures or control the functions of our bodies just like the blueprints for a house don’t make up the walls or floors or lights or plumbing. However, both DNA and blueprints both give the directions or instructions for how structures should be put together. The blueprints tell the builders and contractors how to assemble the building, how big it should be, what materials to use, what shape it should have. Similarly, DNA ultimately directs the ribosomes on how to assemble amino acids to make proteins. These proteins then form the structures of our bodies, regulate chemical reactions, and control what traits (characteristics, how we look and act) will be expressed (seen).
Because DNA is passed on to an organism’s offspring, the traits that are coded for by the DNA can get passed on to the offspring and the offspring can express those traits (Like a home builder passing on the blueprint to his son so that the son can build the same type of house).
The central dogma (rule) of biology is DNA into RNA into Proteins. DNA is found in the nucleus of every cell. The DNA is transcripted (copied) into a different form of genetic code called RNA. The RNA travels from the nucleus out to the ribosomes. The ribosomes translate (convert) the RNA into proteins by connecting amino acids according to the directions of the RNA (which is the directions stored in the DNA).
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To continue our construction analogy, the DNA is the blueprints sitting in the office (nucleus). The directions in the blueprints are read and copied down by the contractor (RNA). The contractor carries this information to the construction workers (ribosomes) and tells them what kind of structure to build. The construction workers use different materials (different amino acids) and put them together to form parts of a building like walls, floors, windows, lights, and plumbing (different proteins).
Must Know
• DNA codes for proteins, which leads to the expression of traits in our bodies.
• Because DNA is passed on to an organism’s offspring, traits coded for by DNA can be passed on to the offspring who may express those same traits.
• Traits that are inherited by offspring through DNA from the parents are called heritable traits.
• Transcription makes RNA based on the DNA. Translation uses RNA to guide the formation of proteins.
Review Questions
1. Cells secrete enzymes (a type of protein) that have been assembled based on the code within the DNA. Which of the following accurately describes the processes involved?
a. DNA is transferred directly into enzymes
b. DNA undergoes transcription, which forms RNA. RNA then is translated into amino acids
c. DNA is replicated and then transcribed into enzymes
d. DNA is translated into RNA and then replicated into DNA-enzyme hybrid molecules
2. The following cell structures involved in protein synthesis are located within cells:
- Nucleus
- Endoplasmic Reticulum (ER)
- Ribosomes
Which of the following best explains the relationship between these structures?
a. The nucleus makes proteins-proteins wind through the ER-proteins are activated
b. Nucleus directs ER to assemble proteins- ribosomes surround proteins- proteins are activated
c. ER creates protein-DNA in the nucleus codes for ribosomes to surround proteins- proteins are activated
d. DNA in the nucleus codes for proteins- proteins are assembled in the ribosomes and then shipped to ER-proteins are activated in the ER
3. Which of the following best describes the interaction between RNA and DNA during protein synthesis?
a. RNA carries the code to the nucleus where DNA translates the code into a protein
b. DNA travels to the ribosome where RNA translates the code into proteins
c. RNA carries the code form the DNA in the nucleus to the ribosomes for protein synthesis
d. DNA travels to the cytoplasm while RNA remains in the nucleus
4. The process of transcription during which DNA is copied into RNA occurs in the
a. Cell membrane
b. Cell cytoplasm
c. Cell nucleus
d. Outside of the cell
5. Genetic in the cell usually flows in one species direction. Which of the following best represents this flow?
a. DNA ( Protein ( RNA
b. Protein ( RNA ( DNA
c. RNA ( Protein ( DNA
d. DNA ( RNA ( Protein
6. Amino Acids link together to form proteins. In which cellular organelle would this process occur?
a. Mitochondria
b. Chloroplasts
c. Ribosomes
d. Nucleus
7. Six generations of field mice have had a distinct ear shape. This ear shape is seen in each generation because it is most likely
a. A heritable trait
b. A random mutation
c. The result of certain environmental conditions that have remained constant
d. A parasitic infection spread through the population causes the ears to become deformed.
|3.3.B.e |Identify possible external causes (e.g., heat, radiation, certain chemicals) and effects of DNA mutations (e.g., altered proteins, which may affect |
| |chemical reactions and structural development) |
Key Vocabulary
• Mutation- change in the sequence (order) of nucleotides in DNA
Overview
When thinking about mutations, it is important to remember what DNA is exactly. DNA is a long strand of nucleotides joined together. Each of the four possible nucleotides is like a letter and so the order of the nucleotides determines what trait is being coded for (just like the order of letters determines what word is being spelled). Mutations occur when there is a change in the order of nucleotides. If the order of the nucleotides changes, then the trait being coded for could possibly change as well just like changing the order of letters changes what word is being spelled.
Mutations can occur in several ways. A frame shift occurs when how the letters are grouped together changes. A point mutation results when just one nucleotide is changed. Mutations can also occur if nucleotides are added or deleted. The diagram below uses the English alphabet to exemplify each of these mutations. Remember that each three-letter word represents a different amino acid and that the amino acids together form a protein (just like the words together form a sentence). Notice how even a slight change in the nucleotides and their orders can result in a big change in the meaning of the sentence. In the same way, even slight changes in our DNA can have a big impact on what proteins are formed in out bodies.
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Mutations can randomly occur or can result from various environmental factors. Random mutations are like little mistakes made during the replication and transcription of DNA. Think about if you had to copy an entire text book word for word. You would probably make at least a few mistakes. Environmental factors such as UV rays from sunlight, exposure to harmful chemicals or overexposure to normally safe chemicals, and radiation can also cause mutations to occur in DNA. Thankfully, organisms have special molecules that are constantly checking the DNA for mutations and are correcting them or replacing that strand of DNA. This prevents many of the mutations that occur from ever affecting which proteins are made.
Must Know
• Mutations are caused by a change in the order of nucleotides in DNA.
• Mutations can occur for several different reasons including random mistakes in copying DNA and changes caused by heat, radiation, UV rays, and chemicals.
• If not corrected, mutations can lead to different proteins being assembled by the ribosomes.
Review Questions
1. Which of these best describes the initial change caused by a DNA mutation?
a. A change in the order of nucleotides
b. A change in the production of enzymes
c. A change in the number of nucleosomes within a cell
d. A change in the number of hydrogen bonds between the bases
1. A strand of DNA is exposed to intense heat. Which of these best describes what will happen to the strand of DNA?
a. The chemical bonds of the DNA molecule will be broken
b. More nitrogen base pairs will add on to the DNA molecule
c. The chemical bonds of the DNA molecule will be strengthened
d. The nitrogen base pairs in the DNA molecule will switch places.
2. Which of the following would result in a mutation occurring?
a. A nucleotide being added to the strand of DNA
b. A nucleotide being removed from the strand of DNA
c. Two or more nucleotides switching places
d. All of the above will result in a mutation
3. Mutations may result in which of the following?
a. Changes in appearance
b. Changes in immunity to disease and disorders
c. Changes in the viability of offspring (the chance that the offspring will survive)
d. All of the above
4. What is the most common affect of a mutation?
a. Mutations have no affect.
b. Mutations cause cells to maintain their normal functions under all conditions.
c. Mutations cause different sequences of amino acids to be assembled resulting in different proteins being formed.
d. Mutations cause the correct sequence of amino acids to be assembled resulting in the correct formation of proteins by ribsomes using RNA.
|3.3.C.a |Recognize the chromosomes of daughter cells, formed through the processes of asexual reproduction and mitosis, the formation of somatic (body) cells |
| |in multi-cellular organisms, are identical to the chromosomes of the parent cell |
Key Vocabulary
• Daughter Cell- cell(s) produced by division of a cell/nucleus
• Mitosis- Cell division when a diploid cell divides and forms two diploid cells
• Somatic Cell- cell that makes up the body of an organism (besides sex cells/gametes)
• Chromosome- long strand of DNA that contains genetic information
• Asexual Reproduction- new members of a species are produced from a single parent
Overview
All organisms start as just a single cell. While many stay as a single cell, all of the organisms we can see with our eyes are made up of more than one cell. Many of them are made up of millions, billions, or even trillions (like humans) of cells. Organisms by increaing the number of cells while the size of the cell remains pretty much the same. The cells that make up our bodies are called somatic cells and each somatic cell has exactly the same number of chromosomes as all of the other somatic cells in that organism.
Asexual Reproduction is when new members of a species are produced from a single parent. This can occur in several ways. Binary fission is when a single-celled organism copies its DNA and then divides forming two identical daughter cells. Each of the daughter cells is identical to the parent cell and to each other. Some multi-cellular organisms asexual reproduce through a process called budding. In budding, the new organism forms as part of the parent organism. As the offspring grows, it eventual breaks off of the parent organism and forms a new organism. This type of reproduction is possible because of mitosis.
[pic] [pic]
Mitosis is cellular division in which the DNA is replicated and two genetically- identical daughter cells are produced. Mitosis produces the somatic cells that make up organisms. Mitosis allows organisms in increase the number of cells (and thus their size) as well as produce the cells needed to replace dead cells. The daughter cells produced through mitosis have the exact same number of chromosomes as the parent cell.
[pic]
Must Know
• All organisms are made up of somatic cells, which are the cells that make up organisms’ bodies.
• Mitosis produces two daughter cells that have the same number of chromosomes as the parent cell.
• Asexual reproduction, which can involve mitosis, also produces daughter cells/offspring that are genetically identical to the parent cell.
Review Questions
1. Which term best describes the type of cell division in which parent cells produce daughter cells with the same number of chromosomes as the parent cell?
a. Meiosis
b. Spermatogenesis
c. Oogenesis
d. Mitosis
1. Mitosis occurs in which of the following types of organisms?
a. Only in sexually reproducing organisms.
b. Only in asexually reproducing organisms
c. In both sexually and asexually reproducing organisms
d. It depends on the species of organism.
2. The cells produced by mitosis in a particular organism each have 30 chromosomes. How many chromosomes did the parent cell have?
a. 15
b. 30
c. 60
d. 90
3. The number of chromosomes found in a cell after mitosis is
a. Dependent upon the type of cell
b. Half the number of chromosomes as found in the original cell
c. Twice the number of chromosomes as found in the original cell
d. The same number of chromosomes as found in the original cell
4. A cell with 46 chromosomes undergoes mitosis three times. How many chromosomes will each daughter cell have?
a. 23
b. 46
c. 92
d. 20
5. An organism with 4 chromosomes reproduces asexually. The cells that formed the new organism will have how many chromosomes?
a. 1
b. 2
c. 4
d. 8
6. Mitosis directly plays a role in each of the following processes in a human except
a. An increase in the organism’s size
b. The organism replacing dead or damaged cells
c. The organism developing into a full grown adult version of the organism
d. The organism reproducing
|3.3.C.b |Recognize that during meiosis, the formation of sex cells, chromosomes are reduced to half the number present in the parent cell |
Key Vocabulary
• Sexual Reproduction- process by which two gametes fuse and the offspring have DNA from both parents
• Meiosis- cell nucleus division that divides a diploid cell to form haploid cells. Necessary for sexual reproduction
• Sex Cell- cell involved in sexual reproduction (gamete)
• Gamete- sex cell (female=egg; male= sperm)
• Diploid- cell that has two copies of each chromosome (one from each parent)
• Haploid- cell with only one copy of each chromosome
• Sperm- male gamete/sex cell
• Egg- female gamete/sex cell
Overview
Many organisms that we are familiar with (including ourselves) reproduce sexually. Sexual reproduction is the production of new offspring from the joining of gametes from two parents. Gametes are sex cells (sperm and egg) and they are different from somatic cells. Sex cells are only involved in reproduction and do not make up any of the structures in an organism. Sex cells are formed through a process called meiosis.
Somatic cells are diploid. This means that they have two copies of each chromosome. During meiosis, a somatic cell is divided. Unlike mitosis, meiosis results in 4 daughter cells, each with half the normal number of chromosomes. These cells are called haploid because they have only one copy of each chromosome. Therefore, the gametes of an organism have half the number of chromosomes that somatic cells of that organism have.
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Must Know
• Sexual reproduction is the production of offspring from the fusion of gametes from two parents.
• Meiosis is cell division that results in daughter cells with only one copy of each chromosome (haploid).
• The haploid cells produced by meiosis are called gametes (aka sex cells, sperm (male) or egg (female))
Review Questions
1. Most cells in the human body undergo the process of mitosis. Some specialized human cells undergo the process of meiosis. Which of the following describes the difference between these two processes in humans?
a. Mutations do not occur during mitosis but they do occur during meisois
b. Mitosis results in half as many chromosomes as meiosis produces in each cell.
c. Mitosis does not usually result in variation between offspring and parent while meiosis usually does
d. Meiosis creates new body cells and mitosis produces sex cells.
2. Each body cell of a goat contains 60 chromosomes. The number of chromosomes in a goat egg cell, produced by meiosis, will be
a. 15
b. 30
c. 60
d. 120
3. If the sperm cells of an organism contain 40 chromosomes, how many chromosomes does a kidney cell in that organism have?
a. 10
b. 20
c. 40
d. 80
4. After meiosis, a daughter cell has 26 chromosomes. How many did the parent cell have?
a. 104
b. 52
c. 26
d. 13
5. A parent cell has 16 chromosomes. After meiosis, each daughter cell would have
a. 2 chromosomes
b. 4 chromosomes
c. 8 chromosomes
d. 16 chromosomes
6.
7. Meiosis is distinguished by the fact that parent cells that were diploid divide to form daughter cells that are
a. Haploid
b. Diploid
c. Haploid or diploid depending on the species
d. Haploid or diploid depending on whether or not that species reproduces sexually or asexually
8. How are the cells produced by mitosis and the cells produced by meiosis different?
a. Cells produced by mitosis have two copies of each chromosome while the daughter cells in meiosis only have one copy
b. The cells of mitosis have one copy of each chromosome while the cells produced by meiosis have two copies of each chromosome
c. Mitosis produces cells while meiosis doubles the amount of DNA present in a cell
d. Meiosis produces cells that make up the structures within an organism while mitosis produces cells necessary for sexual reproduction
9. Which of the following is true?
a. Meiosis is necessary for sexual reproduction to ensure that the correct number of chromosomes is maintained when sperm and egg fuse.
b. Meiosis is necessary for asexual reproduction to ensure that the correct number of chromosomes is maintained when budding or binary fission occurs.
c. Meiosis is not necessary for sexually reproduction or asexual reproduction
d. The role of meiosis is dependent on the species
|3.3.C.c |Explain how fertilization restores the diploid number of chromosomes |
Key Vocabulary
• Fertilization- sperm and egg fuse together forming a diploid cell
Overview
We know from the overview in 3.3.C.b that sexual reproduction involves the two haploid gametes fusing together. We also know that those gametes are formed through meiosis and that each gamete has only one copy of each chromosome instead of the two copies that diploid somatic cells have.
Fertilization is the process that restores the diploid number of chromosomes so that the cell can go through mitosis. Fertilization is when the gamete from a male (sperm) and the gamete from the female (egg) fuse together. Because each gamete is carrying one copy of each chromosome, when they join together they form a cell that has two copies of each chromosome (one copy from each parent).
[pic]
Must Know
• Fertilization joins two haploid gametes to form a diploid zygote (cell).
• Fertilization is necessary for the diploid number to be restored. The diploid number must be restored in order for the cell to go through mitosis.
• Fertilization results in cells that have two copies of each chromosomes (one copy from each parent)
Review Questions
1. When a cell with half the normal number of chromosomes is generated during meiosis, how can it eventually have the normal number of chromosomes?
a. By undergoing the six phases of mitosis
b. By forming two distinct nuclei during cell division
c. By combining with a gamete from an organism of the same species
d. By releasing young cells during exocytosis
2. What is the result of the fertilization of an egg by a sperm cell?
a. It restores the diploid number of the chromosomes.
b. It deletes polypeptide chains in the chromosomes
c. It gives offspring more chromosomes than the parents
d. It gives offspring fewer chromosomes than the parents
3. Two gametes, each containing 32 chromosomes fuse during fertilization. How many chromosomes will the zygote cell contain?
a. 32
b. 64
c. 96
d. 138
4. The cell resulting from fertilization has 12 chromosomes. How many chromosomes does each cell of the organism’s parents have?
a. 4
b. 6
c. 12
d. 24
5. What would occur at fertilization if gametes were diploid instead of haploid?
a. The resulting embryo would have twice the normal number of chromosomes
b. The resulting embryo would have the correct number of chromosomes
c. The resulting embryo would have half the normal number of chromosomes
d. The resulting embryo would have four times the normal number of chromosomes
6. An adult organism has 20 chromosomes and reproduces sexually. After fertilization, an embryo of this same species would have how many chromosomes?
a. 10
b. 20
c. 40
d. 80
7. If fertilization fails to occur, a sperm or egg cell will be left with how many chromosomes?
a. The gamete would have twice the normal number of chromosomes
b. The gamete would have the correct number of chromosomes
c. The gamete would have half the normal number of chromosome
d. The gamete would have four times the normal number of chromosomes
|3.3.D.a |Describe the advantages and disadvantages of asexual and sexual reproduction with regard to variation within a population |
Key Vocabulary
• Asexual Reproduction- new members of a species are produced from a single parent
• Sexual Reproduction- - process by which two gametes fuse and the offspring have DNA from both parents
• Genetic Variation- difference in the genetic code between individuals
Overview
All organisms must reproduce in order for their species to continue. However, organisms can reproduce in different ways. Remember that sexual reproduction requires two parents and the offspring have chromosomes from both parents and that asexual reproduction has only one parent and that the offspring have the exact same DNA as the parent. Both types of reproduction have their advantages and disadvantages.
Because only one parent is involved, asexual reproduction can occur very quickly. In fact, some types of bacteria can reproduce as quickly as every 10 minutes. This quick reproduction rate allows many offspring to be generated in short period of time. However, because there is only one parent, the offspring are identical to the parent cell and to themselves. This makes the organisms more likely to be negatively affected by an environmental change. Because they are all identical, if one of them is affected, they are all affected.
Sexual reproduction has the opposite situation. The disadvantage of sexual reproduction is that is occurs much more slowly (as long as three years in some shark species) and that it requires a lot more energy, time, and caring for young than asexual reproduction. Unlike in asexual reproduction though, sexual reproduction involves combing the DNA from two different organisms, resulting in offspring that have genetic variation when compared to each other and to their parents. This increases the likelihood that at least some of the members of that species will be able to survive and or respond to some form of environmental change.
|Type of Reproduction |Advantage |Disadvantage |
|Asexual |Occurs very quickly |All offspring are genetically identical. Results in lower |
| | |genetic variation and increased susceptibility to |
| | |environmental changes |
|Sexual |Offspring are not genetically identical. Genetic variation in |Takes a long time. Requires a lot of parental investment of |
| |the offspring results in increased probability of |time, energy, and resources |
| |surviving/responding to an environmental change | |
Must Know
• Asexual and sexual reproductions have different advantages and disadvantages.
• Asexual reproduction occurs very quickly but has little genetic variation between offspring.
• Sexual reproduction occurs much more slowly but there is great genetic variation between offspring.
Review Questions
1. A plant nursery grew only one type of tomato plant. All of their tomato plants died from the same disease. Which of the following was most likely true about the tomato plant population?
a. They had a lot of resistance to disease
b. They had too few plants to fight the disease
c. They had too much variation in their genes as a result of sexual reproduction
d. They had too little variation in their genes as a result of asexual reproduction
2. Which statement best describes an advantage of asexual reproduction for a population of organisms?
a. A population can increase in number more rapidly
b. A population can develop greater genetic diversity
c. The population can maintain the same number of organisms
d. The population can adapt more quickly to a changing environment.
3. Which of the following is a disadvantage of sexual reproduction?
a. Only one parent is necessary
b. All of the offspring are genetically identical to the parent
c. Reproduction takes longer and requires more parental care and investment
d. The offspring are genetically similar, but not identical to their parents.
4. Which of the following would be an advantage of sexual reproduction over asexual reproduction?
a. The offspring and parent are genetically identical
b. All offspring are genetically identical
c. There is genetic variation between parents and offspring
d. Reproduction occurs very quickly
5. What is a disadvantage of asexual reproduction?
a. All offspring are genetically identical and therefore can be easily wiped out by a negative environmental change.
b. All the offspring are genetically different. Therefore they can’t all take advantage of the same resource, even when there is lots of that resource available.
c. Asexual reproductions require two parents to reproduce.
d. Asexual reproduction often takes a long period of time.
6. Why might asexual reproduction be more advantageous for pathological bacteria (bacteria that makes us sick) than sexual reproduction?
a. Sexual reproduction allows for the bacteria to produce offspring with a great deal of genetic variation that allows immune system to attack it and destroy it more quickly.
b. Asexual reproduction allows the bacteria to reproduce more quickly and therefore they are able to multiply before the body’s immune system can kick in.
c. Asexual reproduction results in all offspring being genetically identical and therefore less susceptible (lower chance of being impacted by) to antibiotic medication
d. Sexual reproduction requires genetic information from two parents and because of the high amount of bacteria in the stomach, it would take awhile for a bacteria cell to find another one of the correct species
|3.3.E.a |Explain how genotypes (heterozygous and homozygous) contribute to phenotypic variation within a species |
Key Vocabulary
• Gene- certain segment of DNA that codes for a particular trait (protein)
• Allele- a version of a particular trait that occurs on a certain section of a chromosome
• Heterozygous- There are two different alleles for the same trait
• Homozygous- Both alleles for a trait are the same
• Dominant- allele that is expressed when the two alleles are different
• Recessive- allele that is only expressed when both alleles for a trait are recessive
• Genotype- combination of all the alleles in an organism that codes for that organism’s traits
• Phenotype- The physical characteristics of an organism caused by that organism’s genotype
Overview
DNA is found in very long strands that coil up and form chromosomes. Different sections of the DNA carry the codes for different traits (hair color, earlobe shape, hairline, etc). Each section of DNA that carries the code for a certain trait is called a gene. There are many genes on a single strand of DNA. Each gene can have more than one version and different versions of a particular trait are called alleles. For example, the same segment on one chromosome may code for red flowers while the same segment on a different homologous chromosome may code for white flowers. Both segments code for the same trait (flower color) and are thus the same gene. However, because they code for different versions of the same trait (one is for red, one is for white), they have different alleles.
Remember that for every chromosome in a somatic cell there are two copies, one from mom and one from dad. This means that for each trait, there are two alleles (one on each chromosome) for the same gene. The chromosome from mom may have the same allele as dad or they might have different alleles. The combination of alleles (coded for by a certain order of nucleotides) is called an organism’s genotype. The genotype determines the phenotype, which is the set of physical characteristics the organism has.
Frequently there are two versions (alleles) of gene. A dominant allele is the allele that will be expressed (the organism will show that physical trait) when at least one of the two alleles is that version. A recessive allele is the version that is expressed only when both alleles are recessive. In other words, if both alleles are the same (which is called homozygous), then that version of the trait will be expressed. If the organism has one dominant allele and one recessive allele (which is called heterozygous), then the trait of the dominant allele will be expressed. The table below shows this and includes an example where the allele for red flowers is dominant to the allele for white flowers and “F” represents that dominant allele.
|Genotype |Allele Combination |Phenotype |Example |
|Homozygous Dominant |FF |Dominant |Red Flowers |
|Heterozygous |Ff |Dominant |Red Flowers |
|Homozygous Recessive |ff |Recessive |White Flowers |
Must Know
• Each organism carries two alleles (two versions) of each gene.
• If both alleles are the same, then the trait they code for will be expressed.
• If the alleles are different, then the dominant allele’s trait will be expressed.
Review Questions
1. In a certain insect, round wings (R) are dominant to pointed wings (r). Which cross will produce the greatest number of genotypic and phenotypic possibilities?
a. rr x rr
b. Rr x Rr
c. Rr x RR
d. RR x RR
2. Which of the following genotypes will result in the same phenotype for both individuals?
I. RR
II. Rr
III. rr
a. I and II
b. I and III
c. II ad III
d. All three will result in the same phenotype.
3. Which of the following individual genotypes indicate two different phenotypes?
a. Rr and Rr
b. rr and rr
c. RR and Rr
d. RR and rr
4. How are genotype and phenotype different?
a. Genotype is the combination of alleles and phenotype is the expression of the alleles.
b. Phenotype is the combination of alleles and genotype is the expression of the alleles.
c. Phenotype is the dominant characteristics while genotype is the recessive characteristics.
d. Phenotype is the recessive characteristics while genotype is the dominant characteristics.
5. Which cross will result in offspring that are genotypically and phentypically identical?
a. FF x Ff
b. FF x ff
c. Ff x Ff
d. Ff x ff
6. If the genotype changes, does the phenotype necessarily change?
a. It may. Depending on the genotype, the phenotype may change or it can remain the same.
b. It will always change. No genotypes have the same phenotypes.
c. It will never change. All genotypes have the same phenotypes.
d. It cannot be determined. Genotype does not determine the phenotype.
|3.3.E.b |Predict the probability of the occurrence of specific traits, including sex-linked traits, in an offspring by using a monohybrid cross |
Key Vocabulary
• Genetics- study of genes, heredity patterns, and the variation of traits in organisms
• Monohybrid Cross- mating between organisms where only one trait is followed
• Punnett Square- Tool for predicting the probability that certain genotypes will occur in a cross
• Probability- the percent chance that a certain event or trait will occur
Overview
Over the last several hundred years, scientists have made many important discoveries about how the molecular code inside each of our cells determines how out bodies look and function and this study has developed into its own field of study. Genetics is the study of genes, patterns of heredity (which traits offspring get from each parent), and large amount of variation seen in the traits of organisms. One of the earliest interests of scientists studying genetics was predicting what type of offspring would be produced by a cross (mating) between two parents who each had certain traits. They started by first looking at only one characteristic at a time, which is called a monohybrid cross.
By understanding the role of dominant and recessive alleles and that two different genotypes (homozygous dominant and heterozygous) could produce the same phenotype (dominant), scientists figured out tools that could help them predict what type of offspring would be produced by the cross between certain parents. A Punnett Square is one such tool and allows scientists (and us) to predict the probability (percent chance) that offspring of cross between certain parents will have certain traits.
It is important to remember when using a Punnett Square that each parent carries two alleles for each trait. However, those alleles will be found in different sperm or eggs since each sperm or egg carries only one allele. This is why the alleles from mom and dad are split up when using a Punnett Square.
Using a Punnett Square Calculating Probability from Punnett Square
Example Cross: Aa x AA
1. Copy one set of alleles across the top. 1. Count the number of squares with each type of
genotype.
2. Copy the other set of alleles along the side. Homozygous Dominant ( )= 2
Heterozygous ( )= 2
Homozygous Recessive ( )= 0
2. Divide each count by 4.
Homozygous Dominant = 2/4
3. Copy the alleles down each column. Heterozygous= 2/4
Homozygous Recessive = 0/4
3. Covert each fraction to a percentage
Homozygous Dominant = 2/4 = 50%
Heterozygous= 2/4 = 50%
4. Copy the allele across each row. Homozygous Recessive = 0/4 = 0%
Remember that both homozygous dominant and
heterozygous will result in the same phenotype.
Therefore, 100% of offspring in this example will
Must Know
• Punnett Squares are used to predict which genotypes (and therefore phenotypes) the offspring of a particular set of parents will have.
• You must know how to use Punnett Squares and calculate the probability of offspring traits from them.
Review Questions
1. If both parents are homozygous dominant for a trait, what is the probability that an offspring will be homozygous recessive?
a. 0%
b. 25%
c. 50%
d. 75%
2. Predict the probability of the occurrence of tall (dominant trait) pea plants from a monohybrid cross between heterozygous tall pea plants.
a. 25%
b. 50%
c. 75%
d. 100%
3. Using the cross above, what is the probability of having plants with the heterozygous genotype?
a. 0%
b. 25%
c. 50%
d. 75%
4. If a homozygous recessive individual is crossed with a heterozygous individual. What is the probability of having a heterozygous offspring?
a. 0/4
b. 1/4
c. 2/4
d. 4/4
5. Which genetic cross will result in all offspring having the same genotype and phenotype?
a. RR and rr
b. Rr and rr
c. RR and Rr
d. Rr and Rr
|4.1.A.a |Explain the nature of interactions between organisms in predator/prey relationships and different symbiotic relationships (i.e., mutualism, |
| |commensalism, parasitism) |
Key Vocabulary
• Predator- An animal that hunts, kills, and eats another animal for food.
• Prey- An animal that is hunted, killed, and eaten by another animal for food.
• Predation- Predators hunting other animals for food and prey attempting to escape/prevent being eaten.
• Symbiosis- Long term relationship between members of two or more different species
• Mutualism- Interaction between members of two different species where both species benefit from the interaction
• Parasitism- Interaction between members of two different species where one species benefits and the other suffers from the interaction
• Commensalism- Interaction between members of two different species where one species benefits and the other neither benefits not suffers from the interaction
• Resource- something that an organism requires for survival
•
Overview
Organisms (living things) are constantly interacting with one another. We see this every day when we see humans talking with one another, cats chasing mice, and different kinds of birds trying to eat the same food. Thanks to the Discovery Channel we also get to witness interactions from other parts of the world such as lions chasing down gazelles, goby fish living amongst the spines of sea urchins, and cattle egrets riding around on buffalo. Biologists use special terms to describe these interactions.
Predation is when one species (the predator), hunts, kills, and eats another species (the prey) for food. The size of the prey population is affected by the number of predators, which in turn is affected by the number of prey. A change in one population will most likely lead to a change in the size of the other population.
Symbiosis is different from predation because symbiosis occurs between organisms over a long period of time and most often neither organism involved dies because of symbiosis, at least not directly because of the symbiotic interaction. There are three types of symbiosis: commensalism, mutualism, and parasitism.
In commensalism, one organism benefits while the other organism neither benefits nor suffers. The relationship between gobies and sea urchins are an example of this. Gobies are small fish found all over the world. Sea urchins also live in the ocean and have long spines, kind of like the quills of a porcupine. Because they are small, gobies can fit between the spines of the sea urchin. This provides protection for the goby but the sea urchin neither benefits nor suffers from the goby hiding between its spines.
In mutualism, both organisms benefit from the interaction. An example of this is cattle birds and African Buffalo. The cattle birds follow behind the buffalo and eat the bugs that are attracted to the buffalo, its dung, or are disturbed by the movements of the buffalo. The buffalo benefits by having the ticks, mosquitoes, and other insects eaten and removed from its hide.
In parasitism, one organism benefits while the other organism suffers. Any parasite is an example of parasitism, but the one we are most familiar with is a mosquito drawing blood out of us. The mosquito benefits (receives nutrients and energy) from the human and the human suffers (itching, swelling, potential to contract disease.
Must Know
• Symbiosis, which is a long term relationship between two species, is different from predation which occurs only once because the prey dies.
• Predation is when a predator hunts, kills, and eats a prey for food.
• Mutualism is when both species benefit from the interaction.
• Parasitism is when one species benefits (the parasite) and the other suffers (the host).
• Commensalism is when one species benefits while the other neither benefits nor suffers.
Review Questions
1. A community of organisms is studied and several interactions were observed and recorded.
|Interaction |Impact on Organism X |Impact on Organism Y |
|A |Harmful |Harmful |
|B |Beneficial |Harmful |
|C |Beneficial |No Effect |
|D |Beneficial |Beneficial |
Which interaction could be an example of mutualism?
a. Interaction A
b. Interaction B
c. Interaction C
d. Interaction D
2. Based on the table in question #1, which interaction could be an example of parasitism?
a. Interaction A
b. Interaction B
c. Interaction C
d. Interaction D
3. Pilot fish and sharks often live together. The pilot fish eat parasites off the shark while gaining protection from predators. What type of relationship do pilot fish and sharks share?
a. Mutualism
b. Commensalism
c. Parasitism
d. Predation
4. Golden orb-weaver spiders are know for spinning very large and complex webs. Insects of all kinds fly into the web and are caught. The orb-weaver spider then feeds on them. This is an example of
a. Parasitsim
b. Mutualism
c. Commensalism
d. Predation
5. Which of the following best illustrate the concept of parasitism?
a. Anacondas, large snakes found primarily in South America, which kill and eat fish, birds, and small and medium-sized mammals.
b. Tiny mites that live at the base of human eye lashes and eat microscope bugs that fly near a humans face; however, they offer not benefit nor harm to humans.
c. Tsetse flies, large biting flies found in Africa, feed on the blood of living vertebrate mammals such as humans and livestock.
d. Hummingbird hawkmoths collect nectar from colorful flowers. In doing so, pollen collects on the hawmoth. When the hawkmoth moves on to another flower, some of the pollen is deposited on that flower, which is necessary for the flowers to reproduce.
6. Researchers in India have found that if a golden jackal is expelled from its pack, it will sometimes join small groups of Bengal tigers. The jackal will follow after the tigers and eat whatever is left of the prey killed by the tigers since it is difficult for the jackal to hunt and kill prey on its own. The tigers tolerate the jackals, however it appears no benefit or harm comes to the tigers as a result of the jackal’s presence. The relationship between lone jackals and tigers is an example of which of the following?
a. Predation
b. Parasitism
c. Commensalism
d. Mutualism
7. Many species of orchids (a type of flower) are epiphytic plants. This means that they live on another organism. In some cases, orchids live on trees but do not harm or help the trees in any way. What type of symbiosis does orchids and trees share?
a. Amensalism
b. Commensalism
c. Mutualism
d. Parasitism
8. Tapeworm eggs live in fleas. A cat or dog may eat a flea and ingest the tapeworm eggs, which will then hatch inside the dog or cat. Adult tapeworms hook on to the intestines of the animal and feed on nutrients from digested food. The host animal is not killed, but suffers from a lack of nutrients. What type of relationship is this?
a. Parasitism
b. Commensalism
c. Predation
d. Mutualism
9. Ant lions are small insects that dig funnel-shaped depressions in sandy areas. They hide in the dirt at the bottom of the funnel. When an ant climbs into the funnel, the ant lion feels the dirt shift and lunges out to grab the ant, shaking it death and then eating it. The relationship between the ants and ant lions is an example of
a. Commensalism
b. Predation
c. Mutualism
d. Parasitism
10. Cuckoo are species of birds that have been known to lays their eggs in the nests of other species of birds, sometimes pushing the eggs of the other bird out of the nest to make room for its own eggs. The Cuckoo then leaves the other bird to incubate it’s eggs and raise its young for them. Cuckoos have been known to attack the host bird if it tries to push the cuckoos eggs out of the nest. This type of interaction is an example of which of the following types of organismal interaction?
a. Mutualism
b. Commensalism
c. Parasitism
d. Predation
|4.1.A.b |Explain how cooperative (e.g., symbiotic) and competitive (e.g., predator/prey) relationships help maintain balance within an ecosystem |
Key Vocabulary
• Cooperation- two or more organisms working together and both organism benefit
• Competition- two or more organisms trying to use the same resource
• Interspecific- between members of different species
• Intraspecific- between members of the same species
• Ecosystem- all the living and non-living factors that are found in a particular area
Overview
Organisms of all kinds are constantly interacting with members of the same species and members of different species that occupy the same ecosystem. An ecosystem is all of the parts (both living and non-living) that are found in a particular area. For example, the ecosystem of the polar bear includes snow, ice, open water, tundra plants, arctic foxes, hares, seals, fish, walruses, and whales.
Interactions between organisms can be cooperative or competitive. In cooperative interactions, two or more organisms work together and all participants benefit from the interaction. In competitive interactions, to or more organisms are attempting to use the same resource and often only one will be able to while the other loses out.
Interactions, whether competitive or cooperative, that occur between members of the same species are considered intraspecific. Two polar bears trying to eat the same seal is intraspecific competition while elephants working together to protect their young from a predator is an example of intraspecific cooperation. Interactions occurring between members of different species are called interspecific. An arctic fox and a polar bear both trying to catch the same baby seal is an example of interspecific competition. Groupers (large fish) working with moray eels to hunt fish is an example of interspecific cooperation.
Must Know
• Interspecific means between members of different species while intraspecific means between members of the same species.
• Cooperation is when organisms work together; competition is when organisms try to use the same resource.
Review Questions
1. Asian long horned beetles, an invasive species in North America, feeds on living trees. How will they affect the population of plant eating birds that feed on and nests in the trees.
a. The bird population will remain the same.
b. The bird population will decrease due to increased competition for resources
c. The bird population will increase due to the presence of the beetles
d. The bird population will first increase and then decrease.
2. The Canadian Lynx and the snowshoe hare (similar to white rabbit) have a predator/prey relationship. Studies have shown that during years with less vegetation, the lynx population falls. Lynx do not eat vegetation. Hares, however, do eat vegetation. How can the change in the lynx population be explained?
a. With less vegetation, the hare is more visible and the lynx can find the prey with greater ease
b. Less vegetation leads to an increase in the number of lynx births and fewer resources to be shared
c. Less vegetation indicates that a large predator, which can eat the lynx, has moved into the habitat
d. Less vegetation means less food for the hares to eat. As the hares starve to death, there is less food for the lynx to eat.
3. The graph above shows the Mexican Grey Wolf population in a part of New Mexico from 1880-1900. Which of the following could cause the decrease from 1882-1888?
a. The number of animals that eat Mexican Grey wolves increased.
b. The number of wolves killed by humans increased.
c. A disease that affected the wolves spread between packs
d. All of the above.
4. Wolves, as predators in the forest, eat deer. Scientists have noticed that when deer populations decrease, it is several months before the wolf populations also decrease. Why is this the case?
a. The wolves aren’t hungry for a while
b. It takes some time before the wolves begin to leave the area or die of starvation in response to the decline in the deer population.
c. The deer have lots of babies right before the population drops so there is some food for the wolves to eat.
d. Wolves catch deer and store the bodies in the ground to eat later.
5. Rabbits introduced into Australia over 100 years ago have become a serious pest to farmers. The rabbit population has increased so much that they now have displaced many native species of plant eaters. What is the most logical explanation for the increase in the rabbit population?
a. The rabbit experience a high fatality rate
b. There are few effective predators eating the rabbits
c. There is an increase in species that compete with rabbits
d. Rabbit reproductive success has decreased
6. Two male dogs are fighting over access to a female dog. This is an example of what type of competition talked about in class?
a. Predator/Prey Competition
b. Interspecific Competition
c. Intraspecific Competition
d. Non-specific Competition
7. A population of rabbits lives in a forest. During the last several years, there has been little change in the number of rabbits in this population. Which of these would most likely cause the number of rabbits to decrease?
a) a decrease in disease
b) a decrease in habitat resources
c) a decrease in competition
d) a decrease in predation
|4.1.B.a |Identify and explain the limiting factors (biotic and abiotic) that may affect the carrying capacity of a population within an ecosystem |
Key Vocabulary
Biotic- any part of the environment that is, or was, living
Abiotic- factors in the environment that not, and have never been, living (temperature, water, soil)
Habitat- The biotic and abiotic factors that make up the area an organism lives in
Niche- the unique combination of factors (biotic and abiotic) that an organism needs to survive; the role an organism plays in the environment.
Carrying Capacity- number of individuals that can be sustained by the resources of an environment
Population- all the members of a species in a particular area
Overview
The components or parts of any environment can be divided into two categories, biotic and abiotic. The abiotic factors of an environment are anything that has never been living. This includes things like dirt, water, gases, rocks, and chemicals. Biotic factors are those parts of the environment that are or were living. Biotic factors include plants and animals, and anything that comes from plants or animals.
Any organism has an area where it lives because that area has the necessary biotic and abiotic factors for that organism to survive. Many times, the general ecological characteristics required by an organism are shared by many other species. The area with this combination of general requirements is called an organism’s habitat. However, because of interspecific competition, organisms cannot all use the same parts of the habitat. Instead each species occupies a different niche. A niche is the unique combination of factors from the habitat that a species actually uses for survival and is the job or role that a species plays in the environment. So while a barn owls, field mice, deer, woodpeckers, and raccoons may all be found in the same woodland habitat, they each have a different part of the habitat they depend upon for survival.
Population refers to how many members of a particular species live in a given habitat. For example, the population of Yellowstone National Park bison is about 3000 animals. That means that 3000 bison live in the area that makes up Yellowstone. The size of the population depends on how much of the resources required by that species is available, how many competitors those resources have to be shared with, and how many predators are present. The largest population that can be sustained (continuously supported) based on the available resources and amount of competition and predation is called the carrying capacity. If the amount of available resources increases or competition and predation decrease, then the carrying capacity will increase. The carrying capacity will decrease if the amount of competition and/or predation increase or if the amount of resources decrease.
Must Know
• Habitat is where an organism lives; niche is the specific role the organism has or part of the habitat it uses.
• Carrying capacity is the maximum number of individuals of a species that a habitat can support.
• Biotic is anything that is or was living. Abiotic aspects of the environment were never living.
Review Questions
1. Which change would most likely increase the size of a population of sunfish living in a lake?
a) The amount of available food.
b) The number of sunflower fish predators.
c) A drought causes most of the lake to dry up.
d) Runoff from nearby factory enters the lake.
1. A type of lichen grows under water on rocks in the ocean. Which of these factors in the lichen’s environment is abiotic?
a) a fish feeding on algae
b) the water currents around the rocks
c) the algae found on the same rocks
d) the organisms living on the ocean floor
2. A land developer wants to control a population of hawks. He decides to solve the problem by clearing out the land’s fields. How will this action most likely control the population?
a) The population of hawks will increase due to decreased competition.
b) The hawks will experience more crowding and the population will decline.
c) There will be fewer predators of the hawks, so their population will increase.
d) The food supply of the hawks will decrease, causing the population of hawks to decrease.
3. Which of the following abiotic characteristics would affect a population of fish’s ability to grow and reproduce?
a. The amount of zooplankton and phytoplankton (tiny water plant and animals that are a fish food source) in the fish’s habitat
b. The population size of other fish species
c. The population size of predatory fish species
d. The temperature of the water in the fish’s habitat.
4. Deer share the open plains with other grazing animals and predators. Which of the following would lead to a decrease in the deer population?
a. A reduction in the predator population
b. An increase in the number of other grazing animals
c. A reduction in the grazing animal population
d. An increase in restrictions on the hunting of deer
5. Which of the following is a biotic factor that would be directly responsible for limiting the size that a polar bear population can grow to?
a. The amount of sunlight the polar bear habitat receives.
b. The availability of seals (which the polar bears eat) in the bears’ habitat.
c. The numbers of inches of annual snow fall.
d. The availability of minerals during the summer months.
8. Lions and hyenas both live on the African Plains. Lions hunt and kill large game (zebras, elephants, water buffalo, gazelle). Hyenas mainly scavenge, feeding off the left over dead bodies of animals killed by predators or disease. Lions and hyenas have coexisted in the same habitat for a long period of time. How does this affect the carrying capacity of the African Plains?
a. Because lions and hyenas utilize the same resources, there is a lower carrying capacity than there could be.
b. Because lions and hyenas utilize different parts of the same resource, more species are supported thus increasing the carrying capacity.
c. The carrying capacity is lower because the large game animals are being killed.
d. Carrying capacity only measures plant species; predators and scavengers do not affect it.
|4.1.D.a |Predict the impact (beneficial or harmful) a natural or human caused environmental event (e.g., forest fire, flood, volcanic eruption, avalanche, acid|
| |rain, global warming, pollution, deforestation, introduction of an exotic species) may have on the diversity of different species in an ecosystem |
Key Vocabulary
Diversity- a broad variety; many different kinds
Acid Rain- rain that contains pollutants that cause the rain to be more acidic than normal
Deforestation- the removal of trees from an area of the forest
Overview
By using your understanding of the various relationships between organisms, you can predict the impact that different environmental changes will have. Be sure when analyzing questions addressing this issue, be sure to careful read the entire question and all of the answer choices and think through what is the most logical outcome.
Review Questions
1. If a fire burns down most of a forest, what would most likely happen to the biodiversity of this community immediately after the fire?
a. The biodiversity will increase since more species will be present after the fire
b. The biodiversity will decrease since more species will be present after the fire
c. The biodiversity will increase since fewer species will be present after the fire
d. The biodiversity will decrease since fewer species will be present after the fire
2. An isolated population of fritillary, a species of butterfly, lives in a damp meadow. The fritillary larvae feed only on a species of plants that lives in the meadow. One summer, a virus wipes out the violet plants. As a result of the absence of violets, the fritillary population will most likely
e. Increase
f. Decrease to a level near extinction
g. Switch to a different type of food
h. Evolve immediately into a new species of butterfly
3. A gardener has a flower garden that is infested with aphids (a small bug that only eats the leaves of plants causing the plants to die). He buys 100 ladybugs to put in his garden. Ladybugs are natural predators of aphids. What will be the result of introducing the ladybugs into the garden?
a. The ladybugs will eat the flowers instead of the aphids
b. The aphids will eat the ladybugs instead of the flowers.
c. An increase in predators (ladybugs) will cause an increase in prey (aphids).
d. An increase in predators (ladybugs) will cause a decrease in prey (aphids).
5. A farmer plants the same type of wheat, which requires a large amount of nitrogen in order to grow successfully, in his fields for 12 straight years. He plants no other crops in his fields during this time. Which of the following is more likely to occur
a. The farmer will be able to keep growing wheat without adding any extra nitrogen.
b. The amount of wheat that the farmer is able to grow each year will get smaller and smaller if he adds nitrogen to the soil in the form of fertilizer.
c. The amount of wheat that the farmer is able to grow each year will stay about the same if he adds nitrogen to the soil in the form of fertilizer.
d. The amount of oxygen in the soil will decrease as nitrogen levels decrease.
6. Logging (cutting down trees to use for making houses and paper) obviously causes trees to die. What impact can this have on nearby rivers?
a. The roots of trees are important for holding dirt in place. If the trees are cut down and the roots die, then the runoff will carry more dirt into nearby bodies of water, making the rivers dirty and negatively affecting the animals that live in the river.
b. The dead roots and stumps of the trees will fall into the river, making it so that boats can move up or down the river.
c. Since trees grow in the ground and rivers are made of water, what happens to trees has no effect on nearby rivers.
d. Since trees require water, if they die, less water will be taken out of rivers.
7. After humans introduce new animals to an area, often the new species and an existing species must attempt to occupy the same habitat and role in that habitat. What will most likely happen to these two species?
a. Neither of the species will be able to survive in that community
b. Each of the species will start eating new foods and live in different areas.
c. The species will successfully share the resources found in the habitat
d. One species will be more successful while the other species will either not survive or be forced to find a new area to live in or different food resources
8. Naturally occurring forest fires are a regular feature of the forest ecosystem and are beneficial to the health of that ecosystem. Why might this be the case?
a. This is not the case. Fires are always destructive.
b. Fires are beneficial because they drive out invasive animal species
c. Fires are beneficial because they destroy large trees
d. Fries are beneficial because they help clear out the dead plants and trees, returning those nutrients to the soil. They are also result in more sun reaching the forest floor, which allows smaller plants to flourish. This results in an increase in the number of different plants in a forest.
9. Volcanoes can be quite destructive, covering tens, if not hundreds or thousands, of square acres with ash, rock, hardened lava, and soot. What impact does the eruption of a volcano immediately have on the biodiversity of the ecosystems surrounding it?
a. The eruption of a volcano will result in an increase in biodiversity of the area
b. The eruption of the volcano will have no impact on the biodiversity of the area
c. The eruption of the volcano will result in a decrease in biodiversity of the area
d. A prediction in changes in biodiversity as the result of a volcano is not possible
10. Prairies that have been used for a long time to graze animals like cows often become taken over by only a few types of plants that the cows don’t like to eat. When scientists try to restore the prairie, they often burn away the existing plants and plant a large variety of seeds of native species. What effect does this have on the biodiversity of prairie ecosystems?
a. The introduction of a variety of plants result in an increase in the biodiversity.
b. The restoration technique of burning the existing plants and planting new ones decreases the biodiversity.
c. Plants aren’t considered part of the biodiversity of an ecosystem and therefore don’t count.
d. A prediction in changes in biodiversity as the result of restoration efforts is not possible.
|4.2.A.c |Predict how the use and flow of energy will be altered due to changes in a food web |
Key Vocabulary
Consumer- organism that gets its energy from other organisms
Producer- organism that gets energy from abiotic sources (Sun, hot water). Generates it’s own energy.
Decomposer- organism that gets it energy by breaking down dead organisms
Carnivore- organism that gets energy by eating only other animals (eats only meat)
Omnivore- organism that eats both plants and animals
Herbivore- organism that only eats plants
Overview
The flow of energy through an ecosystem is one the biggest factors in determining what kind of (and how many) species are found in the ecosystem. Almost all of the energy on earth comes from the sun. Energy, in the form of sunlight, is captured by organisms like plants and turned into a form of energy that can be used by living things. Organisms that can capture energy from non-living sources and turn it into energy usable by living things are called producers. Energy is then transferred from the producers to the consumers when consumers eat the producers (i.e. energy is transferred to deer when they eat grass) and when consumers eat other consumers (mountain lion gets energy from eating a deer). Energy is then transferred back to the soil to be used by producers when organisms called decomposers breakdown dead organisms into different small molecules.
Scientists use specialized terms to describe where consumers get their energy. Herbivores get their energy by eating only plants. Omnivores get their energy by eating both plants and animals. Carnivores get their energy from eating only meat. The diagram below shows the flow of energy through the various levels of the ecosystem. The arrows indicate the direction of the flow of energy.
Tertiary Consumer
Secondary Consumer
Primary Consumer
Producer
Carnivore
Omnivore
Herbivore
Bobcat
Raccoon
Grasshopper
Grass
Using their knowledge of what different organisms consume, scientists can create food webs. A food web is a diagram that shows how energy flows between organisms in a particular ecosystem. It also allows scientists to predict how changes in the environment will affect the different species found there. It is important to remember that in a food web, the arrow shows the flow of energy by point toward the organism that is consuming the energy. Two examples of a food web (one simple, one much more complex) are shown below. Using the food web, you can determine which organisms will affected most directly by a change in the population size of one organism.
[pic] [pic]
Must Know
• Consumers eat other organisms or energy while producers convert energy from abiotic sources into a form they can use.
• A change in the population size of one organism in a food web will affect the organisms above and below it in the food chain.
• The arrow in a food web indicates the direction that energy is flowing. In other words, it is point toward the animal that is doing the eating.
Review Questions
1. What impact would removing all of the decomposers from an ecosystem have?
a) Organisms would live longer because they would not decompose.
b) Erosion would slow down in the area but increase in areas nearby.
c) There would be less groundwater available to organisms in the area.
d) Nutrients would not be recycled, and life could not exist in that area.
2. Which best describes the interaction between autotrophs and heterotrophs?
a) One competes with the other for access to sunlight and soil.
b) One decomposes the other to release nutrients back into the soil.
c) One helps produce the other in a mutually beneficial relationship.
d) One consumes the other to use energy that originally came from the Sun.
3. In a deciduous forest ecosystem, a white-tailed deer eats tree leaves while a Cooper’s hawk hunts a downy woodpecker. In the ground, earthworms break down leaves. The Cooper’s hawk is classified as a
a) Producer
b) Decomposer
c) Parasite
d) Consumer
4. The figure below shows an energy pyramid for an ecosystem.
Tertiary consumers
Secondary consumers
Primary Consumers
Producers
What happens to the amount of energy in the pyramid as it moves up through the different levels?
a) It increases
b) It decreases
c) It increases and then decreases
d) It decreases and then increases
Use the diagram below to answer the following question.
[pic]
6. What impact would removing all of the producers from this ecosystem have?
a. Consumers would live longer because they wouldn’t have to complete with the producers.
b. Erosion would slow down in that area but increase in areas nearby
c. The consumer populations would decrease due to a lack of resources.
d. Some populations of consumers would increase while other populations decreased.
7. A disease kills off all the insects in the ecosystem above. What species will be least affected immediately?
a. Rabbit
b. Shrew
c. Mouse
d. Deer
8. A group of hunters kill all the deer in the area. Which of the following is most likely to happen?
a. The grass population will decrease
b. The mouse and shrew populations will increase because they have access to more food
c. The snake population will decrease
d. The cougar population will increase
9. The entire mouse population is wiped out by a disease similar to the Plague. Which of the following is most likely to occur?
a. The snake population will still have food and therefore survive
b. The deer population will increase
c. The shrew population will decrease because it is now the sole food source of the snake
d. The rabbit population will decrease
10. A herbicide is used to kill off all of the plants and trees in the area. Besides the plants and trees, which organisms would be affected first?
a. Deer
b. Cougar
c. Shrew
d. Snake
|4.3.B.b |Explain the importance of reproduction to the survival of a species (i.e., the failure of a species to reproduce will lead to extinction of that |
| |species) |
Key Vocabulary
Reproduction- the production of new members of a species
Species- group of organisms that are very similar and can bred and produce fertile offspring
Extinction- all members of a species die and none of that species is left living anywhere in the world
Overview
The term species is widely used by scientists and it is important to know what they mean by it. A species is a group of plants or animals that have very similar characteristics and can mate with one another to produce offspring that are capable of reproducing. There may be differences between members of the same species (humans are all the same species but there are lots of differences between them), but they share the same set of possible traits.
In order for a species to continue, members of that species must reproduce and there must be at least as many births as there are deaths. This may seem like an obvious point, but it is important to think about what this means. If for any reason (genetic mutation, environmental disruption, lack of resources, loss of habitat, small and scattered populations) a species is unable to successfully produce fertile offspring, that species will go extinct when the remaining members die out. Extinction occurs when all members of a species die and there are no members of that species left living anywhere in the world.
Must Know
• Reproduction is necessary for any species to survive.
• Without reproduction, a species will go extinct and there will be no living members of that species left.
Review Questions
1. Which of the following best illustrates natural selection?
a. An organism with favorable genetic variations will tend ot survive and breed successfully
b. A population monopolizes all of the resources in its habitat, forcing other species to migrate
c. A community whose members work together to utilize al existing resources and migratory routes
d. The largest organisms in a species receive the only breeding opportunities
2. The papaya mealybug is a pest (bug) that poses a threat to many tropical plants. Which fate of the mealybug would result from the inability of the species to reproduce?
a. The species would mutate.
b. The species would increase.
c. The species would become extinct
d. The species would continue to thrive.
3. The loulu tree in Hawaii reproduces by a seed encased in (surrounded by) a fruit. Non-native species, such as pigs and rats, eat the fruit as a regular part of their diet, drastically reducing the regeneration rate (how many new trees grow) of the loulu. What most likely would be the outcome for the loulu trees in the next century (100 years) if scientists don’t get involved?
a. They would become extinct
b. They would rebound and thrive
c. They would remain at their current levels
d. They would evolve a new way to reproduce
4. The pseudostem borer is a pest (bug) that poses a threat to banana plants. Which fate of the pseudostem borer would result from the ability of the species to reproduce quickly?
a. The species would mutate.
b. The species would decrease
c. The species would become extinct
d. The species would continue to thrive and take over banana crops.
5. In order for a species to survive, which of the following must be true?
a. More individuals must die than are born
b. More individuals must be born and survive than die
c. Each generation must produce slightly more offspring than the generation before
d. Both b and c
6. The Preebles Jumping Mouse is a species of field mouse that is found near ponds and marshes at lower elevations in Colorado. Human activity in its habitat disrupts the mouse’s breeding behavior and leads to a decline in reproductive success. This decline in reproductive success will most likely lead to which of the following outcomes?
a. The Preebles Jumping Mouse population will increase in areas of human activity
b. The Preebles Jumping Mouse population will remain constant in areas of human activity
c. The Preebles Jumping Mouse population will decrease (and possible go extinct) in areas of human activity
d. It is impossible to predict the effect of human activity on the Preebles Jumping Mouse population
7. The alligator gar is a large fish with a very long snout and narrow body. If changes in the water the gar lives in prevent gar eggs from developing properly, what will most likely be the result?
a. The alligator gar population will grow
b. The alligator gar population in that body of water will go extinct
c. The alligator gar population will adapt to the new water conditions
d. The alligator gar population will stay the same.
|4.3.C.a |Identify examples of adaptations that may have resulted from variations favored by natural selection (e.g., long-necked giraffes, long-eared jack |
| |rabbits) and describe how that variation may have provided populations an advantage for survival |
Key Vocabulary
Evolution- change in species over time. Changes in characteristics of a species so that the descendents are different than the ancestors
Adaptation- inheritable trait that increases survival and reproduction rates of an organism and therefore becomes more common in a population
Variation- differences in traits/characteristics resulting from different combinations of DNA
Natural Selection- Individuals with variations/adaptations that increase survival produce more offspring over time than those without the variation/adaptation
Survival Advantage- some trait, characteristics, or skill that increases an organism’s ability to survive
Overview
Evolution is the change in the characteristics of a species over time leading to the descendents being different (sometimes drastically) from the ancestors. Evolution occurs via a process called natural selection. Natural selection occurs when some members of a species have some characteristics, called survival advantages, that increase their ability to survive and reproduce. Because they are able to reproduce more successfully then other members of the species, more members of the next generation of offspring are carrying the successful traits. Because the offspring have the successful traits, they are able to reproduce more successfully and more of their offspring will have traits that lead to survival advantages. This continues on and on over millions of years. Slowly over time, the which traits are most common in a species change so that the common traits are the ones that allow the species the greatest survival advantage. A characteristic of a species that has changed to match the conditions of the environment and allows an organism to survive and reproduce more successfully in that environment is called an adaptation.
Adaptations result from certain variations in a species allowing that species to survive and reproduce more successfully in a specific environment. Variations are different versions of the same trait and occur because of variations in the DNA of the species.
For example, a hypothetical mouse species lives in a field that is covered with dark green grass all year long. Within the mouse population there is some variation in fur color. So mice have very dark grey coats while some have medium grey coats while others have light brown coats. This variation occurs because there are different versions (remember we call these alleles) for the fur color gene. The mice with the dark coat color are harder for predators to spot because they blend in with the dark green grass. The mice with the light brown coats can hide as well and predators can easily spot them. The medium grey mice get eaten more than the dark coats but not as much as the light coats. Based on how many survive to reproduce, more dark coats are born that next spring then either of the other colors. Because they have the darker color, more of them will survive. This will continue generation after generation until most, if not all, of the mice are the dark grey color. The darker color fur would then be considered an adaptation the mice have for survival.
Must Know
• All species have some variation in traits. Some of these variations lead to better chances of survival than others.
• Variations that lead to a survival advantage for a species will result in more offspring with the successful variations being born. As this process repeats itself, the variations become common in the species and are considered adaptations.
• The process by which variations that lead to increase reproductive success become more common over time is called natural selection.
• Natural selection leads to changes in species over time which is called evolution.
Review Questions
1. In shallow tropical seas, brightly colored clown fish find protection from predators by swimming among the stinging tentacles of sea anemones. Unlike other fish, the clown fish is unharmed by the stinging tentacles. Scientists think the ability of clown fish to remain unharmed among the tentacles is the result of:
a) Succession
b) Parasitism
c) Natural selection
d) Selective breeding
2. A species of finches has been studied on one of the geographically isolated Galapagos Islands for many years. Since the island is small, the lineage of every bird for several generations is known. This allows a family tree of each bird to be developed. Some family groups have survived and others have died out. The groups that survive probably have:
a) interbred with other species.
b) inherited some advantageous variations.
c) found new places on the island to live.
d) been attacked by more predators.
3. A species of flower lives in an environment that has always had an abundance of rain but is now experiencing less rainfall each year. Which variation within the flower population would be beneficial in terms of natural selection?
a) a difference in pollen production which affects reproduction
b) a difference in the color of petals which attract pollinators
c) a difference in the length of the roots use to collect water underground
d) a difference in the length of the stems which changes the height of the plant
4. Geospiza fortis was the only bird species on an island until 20 years ago, when Geospiza Margnirostis arrived. They competed for large seeds as a source of food. Geospiza fortis started eating smaller seeds. The development of which trait would benefit Geospiza fortis in this situation?
a) Brighter feathers
b) A smaller beak
c) A large wingspan
d) Sharper claws
5. How does the graph support the role of natural selection in the survival of different groups of birds?
a) More large beaked birds survive during dry years
b) All birds survived during wet years
c) Fewer birds survived during wet years
d) Medium beaked birds are most successful
[pic]
|4.3.C.c |Explain how environmental factors (e.g., habitat loss, climate change, pollution, introduction of non-native species) can be agents of natural |
| |selection |
Key Vocabulary
Climate Change- term used to describe a long-term change in the average climate of an area
Non-native- species that are not normally found in an ecosystem. Have come from a different environment
Pollution- any substance (solid, liquid, or gas) that is released into the environment and causes damage
Overview
Natural selection is based on some variations in a population increasing the reproductive success of the organisms with those traits compared to organisms that do not have those traits. If an ecosystem or the environment where an organism lives have been stable for a long period of time and not much has changed, then the organisms will be pretty well adapted to that environment and little natural selection will be occurring. However, if an environmental change occurs certain variations allow for increased survival over all other variations, natural selection is very likely to occur.
Anything that causes a disruption to an ecosystem with out completing destroying all of the organisms that live there can lead to natural selection. Low to moderate levels of pollution can have this affect. The introduction of non-native species is a common problem in many environments. Because the organisms native to that area have adapted to the environment, the introduction of another species that may act as either a new type of predator or directly competes with native species for resources will result in other those native species with variations that allow for survival to continue while the other native species may be driven extinct.
One of the most talked about factors that could lead to widespread natural selection (and therefore adaptations) or extinction is climate change. Climate change (frequently referred to as global warming) is a trend in which the climate in a given area is changing as a result of average air temperatures increasing. This change in climate may lead to natural selection, as species with variations that allow them to survive and reproduce are able to adapt to the changes.
To continue with our example from CLE 4.3.C.c, if the change in climate results in drought conditions in the area where the mice live, the grass may be a light brown for most of the year. In this situation, the mice with the light brown coats will be able to blend in better than those with the dark grey coats and therefore will be less likely to be eaten by predators. Over time, it would be expected that this environmental change will drive natural selection resulting in most of the mouse population having the light brown fur.
Must Know
• Changes in the environment can create conditions in which certain variations allow organisms to survive and reproduce more successfully than organisms without those traits. This leads to natural selection and eventually the presence of a new adaptation.
Review Questions
1. Which of the following is the most likely explanation for why a field initially is covered with grass but later becomes overgrown with trees?
a. The trees would reach maturity first and reproduce before the grasses could
b. The trees and grasses are not in competition with each other and both would prosper
c. The shorter grasses would outcompete the taller grass and attempt to take all of the sunlight and water before the trees could grow.
d. The taller grasses would outcompete the shorter grasses for resources but would ultimately have to complete with the trees for sunlight and water.
2. What is a reasonable prediction for how gorillas may respond to the continuing destruction of their habitat?
a. The population will increase.
b. The gorillas with traits that allow them to survive in a large area will survive to reproduce.
c. The gorillas with traits that allow them to survive in a smaller area will survive to reproduce
d. No prediction can be made based on the information provided.
3. An ecosystem experiences increased amounts of acid rain. Why can this cause natural selection in a population of shrubs?
a. The shrubs that can tolerate the acidity will survive and reproduce.
b. The shrubs will be forced to compete for food sources.
c. The shrubs cannot survive without pure water.
d. The shrubs will be eaten by omnivores.
4. Artic mammals have very heavy fur coats to help keep them warm. If global temperatures increase a significant amount over the next 100 years, what might we expect to happen to the coat of Artic mammals?
a. The average fur coat will change color.
b. The average fur coat will get heavier and thicker
c. The average fur coat will thin and become less dense
d. There will be no change in the fur coats
5. A population of insects has 75% green individuals and 25% brown individuals. For several summers, droughts occur in the area and the grass remains brown for most of the year. Given that natural selection is occurring, what is the most likely percentage of brown insects after several summers?
a. 0%
b. 10%
c. 25%
d. 60%
6. What might happen to a native plant population if a non-native animal, such as a pig, is introduced onto an island?
a. Plant species may undergo natural selection in order to minimize the competition between themselves and the other plants.
b. The native population of plants will increase.
c. Those native plants that have a bad taste will make up more and more of the plant population.
d. Those plants that are eaten by the pig will reproduce more often than those that aren’t.
7. The antibiotic penicillin was often used to treat bacterial infections caused by staphylococcus. The table below shows the effectiveness of penicillin in killing of a staph. Infection.
|Year |% of staph. Killed |
|1944 |99.9% |
|1951 |60% |
|1999 |20% |
|2007 |2% |
How does natural selection explain these findings?
a. Each individual bacterium develops antibiotic resistance on its own
b. The mutation rate spontaneously increases to cause this increase in antibiotic resistance
c. Bacteria that are resistant to penicillin are more likely to reproduce and pass on their traits to their offspring
d. Antibiotic resistance only occurs when humans genetically engineer bacteria to have it
Common Biology Terms Glossary
Adenosine Triphosphate (ATP)- cell’s energy molecule. Energy is stored in bonds and is released during chemical reactions inside the cell.
Aerobic- reaction that requires oxygen in order to happen
Amino Acid- small molecules that join together to form proteins
Anaerobic- reaction that does not require energy in order to happen
Antibiotic- chemical that kills bacteria or slows down how quickly it can grow
Appendage- structure attached to the main part of the body (e.g. leg, eye antenna
Autotroph- organism that captures energy from abiotic sources/sunlight and turns it into energy that it can
Bacteria- prokaryotic organisms. One of the three domains of life.
Biodiversity- how many different types of living things are found in one place
Biome- all the organisms (plants, animals, and bacteria) that live in areas with a certain climate
Cancer- any disease that results from uncontrolled cell division
Climate- typical, long-term weather patterns of a particular area
Compound- substance made of atoms of different elements bonded together in a certain way
Data- recorded observations and measurements. Usually numbers (e.g. results of an experiment)
Detritivore- organism that eats dead organisms
Double Helix- Structure of DNA molecules is caused by the tension resulting from the bonds between molecules that make up DNA. Resembles a twisted ladder.
Ecology- discipline within science that studies interactions between living things and between living things and the environment they live in
Element- substance made of only one type of atom.
Estuary- area where a river flows into the ocean
Fossil- preserved remains (or evidence) of an organism from the past
Global Warming- trend of increasing average temperatures worldwide
Hemoglobin- protein in blood cells that allow the blood cells to carry oxygen and other gasses
Heterotroph- organism that obtains its energy by eating other organisms
Hypertonic- solution that has a higher concentration of molecules dissolved in it compared to other solutions
Hypotonic- solution that has a lower concentration of molecules dissolved in it compared to other solutions
Indicator Species- species whose presence in an ecosystem can indicate or give information about other species in the same habitat
Insecticide- Chemical that is used to kill insects
Isotonic- solution that has the same concentration of molecules dissolved in it as other solutions
Lipid- nonpolar molecule made up of carbon, oxygen, and hydrogen molecules bonded together. Ex. fats & oils
Phospholipid- molecule made of a phosphate group, two fatty acids, and a glycerol molecule. Makes up cell membranes
Product- substance that is formed by a chemical reaction
Reactant- Substance that is used and changed during a chemical reaction (“ingredients”)
Solute- molecules that is mixed into/dissolved in a liquid, most often water
Solution- mixture in which molecules are dissolved in a liquid
BIOLOGY EOC CRIB SHEET
Use this sheet to quickly refresh yourself on the different topics covered on the EOC. It is not a complete description of everything you must know but it should help remind you of the big ideas you should be studying.
|CLE |Concept |Have To Know |
|3.1.B.a |Cell Growth and |Organisms grow by increasing the number of cells within them |
| |Differentiation |Cells specialize (or differentiate) so that multiple complicated functions can occur simultaneously |
| | |Cell differentiation occurs almost entire during pregnancy |
|3.1.C.b |Structure/ Function of |Nucleus-Contains DNA, controls cells functions and other organelles |
| |Organelles |Mitochondria- where cell respiration turns oxygen and glucose (C6H12O6)into ATP and CO2 |
| | |Chloroplasts- Only in plants, where photosynthesis uses CO2, Sunlight and Water to produce glucose (C6H12O6) and oxygen |
| | |Golgi Bodies- Package cell products and move materials around the cells |
| | |Ribosomes- link amino acids together to form proteins |
| | |Lysosomes- digest and remove damaged/dead cell material |
| | |Cell Membrane- Regulates what enters and exits the cell |
| | |Cell Wall- Only in plants, provides structure and support |
|3.2.A.c |Organelle Interactions |Protein Synthesis: DNA in nucleus uses RNA to code for protein ( Protein assembled in ribosomes and moved to Endoplasmic |
| | |Reticulum( Protein folded into its active shape |
| | |Chloroplasts produce O2 and C6H12O6 which is used by cell respiration in the mitochondria to produce ATP and CO2. The CO2 is |
| | |then used by photosynthesis. |
|3.2.B.a/b |Photosynthesis/Cell | Mitochondria- All cells, where cell respiration turns oxygen and glucose (C6H12O6)into ATP and CO2 |
| |Respiration |Chloroplasts- Only in plants, where photosynthesis uses CO2, Sunlight and Water to produce glucose (C6H12O6) and oxygen |
| | |Increase in photosynthesis = increase in cell respiration; decrease in photosynthesis = decrease in respiration |
|3.2.F.a |Semi-permeable Membrane |The Cell Membrane regulates what can enter and exit the cell. Prevents waste from building up or harmful molecules from freely |
| | |entering cell |
|3.2.F.b |Movement across Membrane |Osmosis= Movement of water from high water concentration to low water concentration |
| | |Diffusion= movement of molecules from high molecule concentration to low molecule concentration |
| | |Active Transport= movement across a membrane that requires ATP energy; usually large or charged molecules |
|3.2.F.c |Importance of Water |Helps regulate body temperature, blood volume, blood pressure, provides a solution for substances to dissolve in so they can be |
| | |carried by blood, can be both a reactant and a solution for a reaction to occur within, keeps cells firm and membranes soft and |
| | |flexible |
|3.3.B.a |Properties of DNA |Provides the code or blueprint for the structure and function of an organism. DNA is made of nitrogen bases bonded together by |
| | |hydrogen bonds connected to a phosphate sugar backbone. The pulling and tension from the bonds causes the molecule to twist in |
| | |the double helix shape. As the strand of DNA twists and coils it forms a chromosome. A segment of DNA that codes for a trait is |
| | |called a gene. |
|3.3.B.b |Function of DNA |DNA carries the genetic blueprint or code that directs the structure and function of all cells. DNA codes for RNA which carries |
| | |the message to the ribosomes where proteins are made. DNA is expressed as heritable traits in the form of proteins. |
|3.3.B.e |DNA Mutations |Mutation= a change in the order or sequence of nitrogen bases. |
| | |Mutations result in a different protein being coded for |
| | |Heat and strong chemicals can cause the bonds in DNA to be broken. Mutations aren’t seen frequently because usually molecules in|
| | |cells will either fix the mutation or destroy the cell. |
|3.3.C.a |Mitosis |One parent cell produces two daughter cells with the same number of chromosomes (diploid) as the parent no matter how many times|
| | |the cell goes through mitosis |
| | |Used in asexual reproduction and in all organism to increase the number of cells/replace dead cells |
|3.3.C.b |Meiosis |Required in sexual reproduction; Diploid parent cell divides into four cells, each with half the normal number of chromosomes |
| | |(haploid). |
|3.3.C.c |Fertilization |Fertilization is when two haploid cells fuse to form a diploid cell. Fertilization is required to ensure that |
| | |sexually-reproduced offspring have the correct number of chromosomes. |
|3.3.D.a |Sexual vs. Asexual |Asexual reproduction occurs very quickly but the downside is all of the offspring are genetically identical |
| |Reproduction |Sexual reproduction takes more time and two parents, but it produces genetically diverse offspring |
|3.3.E.a |Genotype and Phenotype |Genotype is the combination of alleles (ex. TT OR Tt OR tt) while phenotype is what the organism looks like (TT and Tt both |
| | |produce the same Tall phenotype; tt produces the recessive short phenotype) |
|3.3.E.b |Trait Probability |Punnett Squares are used to determine the % chance that the offspring of two parents will have a certain genotype or phenotype. |
| | |Homozygous Dominant means both alleles are the same and they are dominant (AA), Heterozygous means one allele is dominant and |
| | |one is recessive (Aa), and homozygous recessive means that both alleles are the same and they are recessive (aa) |
|4.1.A.a |Organisms Interacting |Symbiosis= Long term relationship between two species. Mutualism= relationship where both organisms benefit from interacting. |
| | |Commensalism= relationship where one organism benefits and the other neither benefits nor suffers. Parasitism= relationship |
| | |where one organism benefits and the other suffers. Predation= One animal (predator) hunts, kills, and eats another (prey) for |
| | |food. Competition= two members of the same species (intraspecific) or two members of different species (interspecific) competing|
| | |for the same resource. |
|4.1.A.b |Cooperative/ Competitive |An increase in prey(an increase in predators (though it takes a little while for the predators to reproduce so their population |
| |Balance |grows after the prey population has started to grow). A decrease in prey(a decrease in predators (though the predator decrease |
| | |occurs sometime after the prey decrease because it takes a while before the predators leave or die off). Decrease in |
| | |predators(an increase in prey. Increase in predators( decrease in prey. Populations experiencing mutualism will grow or shrink |
| | |together. Species that can outcompete other species will experience population growth while the others will decline. |
|4.1.B.a |Biotic vs. Abiotic |Biotic= something that is or was living (ex. Dead plants, rotting leaves, monkeys, dry skin, bacteria, etc) |
| | |Abiotic= something that was never living (amount of oxygen, elevation, rocks, water, soil, elements, dirt, etc) |
|4.1.D.a |Human Impact |Humans impact the environment by using resources (water, minerals, trees, plants, animals), destroying habitats (logging, |
| | |pollution, silt/dirt in rivers), introducing non-native species, killing native species (gorillas, rhinos, elephants), altering |
| | |the climate (pollution leading to ozone holes or global climate change) |
|4.2.A.c |Energy Flow |Energy from the sun is captured by producers (plants). Primary consumers eat plants (herbivores). Secondary consumers eat both |
| | |plants and animals (omnivores) while most tertiary consumers only eat meat (carnivores). Change in the population at one level |
| | |will causes changes in the populations at the other levels. |
|4.3.B.b |Species and Reproduction |Species= group of organisms with the same (or very, very, very similar characteristics) |
| | |Reproduction= production of new members of a species. Required in order for a species to survive and adapt |
|4.3.C.a |Adaptation and Variation |Adaptation= trait that an species has developed over time that allows it to have a higher rate of survival (ex. Tigers’ stripes,|
| | |long necks of giraffes, lungs of mammals, etc) |
| | |Variation= differences in the characteristics of a species (eye color, hair color, skin color, ear size/shape) |
|4.3.C.c |Natural Selection |Natural Selection= Some members of a species have traits that allow them to survive when other members don’t or at least well |
| | |enough to reproduce. Those that survive are able to reproduce and pass on those successful traits. Their offspring that have the|
| | |successful traits are able to reproduce more effectively and the traits are passed on again. Eventually, almost all members of |
| | |the species have the successful trait(s). |
Remember, studying means…
• Making flashcards for each of the vocabulary terms. Then, quizzing yourself on the terms any time you have a few extra minutes at the bus stop/ride, in line at the store, before you go to bed, etc.
• Using the this crib sheet to do quick refreshers. You can tear it off and carry it around with you. Read over it again and again and again until you can repeat everything on it back to someone without looking.
• Going over the review questions for 5 different CLEs every day. There are 35 CLEs so that means you will make it through all of the review questions in a week. Keep doing this every week until the EOC.
• Forming a study group with people you trust and who you know take learning seriously. Quiz each other by asking them the review questions from this packet and others questions that you come up with on your own.
DON’T FORGET: When you are taking a test, always be R.A.R.E.ing to go…
Read the entire question! (underline key words and ideas)
Anticipate the answer! (decide on what the answer should be before looking at the answer choices)
Review all of the answer choices! (be sure to read each one carefully)
Eliminate the wrong answers! (cross out the answers you know are wrong, then choose the best remaining answer).
-----------------------
National Institutes of Health
Phosphate Molecules
Phosphate Molecules
Fatty Acid Tails (lipids)
Active Transport
Passive Transport
High Concentration
Low Concentration
TIME
Semipermeable Membrane
0% NaCl
40% NaCl
Semipermeable Membrane
33% NaCl
Modified from image found at
B
A
Water
NaCl
sciproject/project/Kingdoms/Bacteria3/eubacteria.htm
DIPLOID
DIPLOID
DIPLOID
HAPLOID
HAPLOID
HAPLOID
HAPLOID
DIPLOID
Haploid Sperm
Diploid Zygote
Haploid Egg
A a
|AA |Aa |
|AA |Aa |
A
A
A a
| | |
| | |
A a
| | |
| | |
A
A
A a
|A |a |
|A |a |
A
A
A a
|AA |Aa |
|AA |Aa |
A
A
express the dominant phenotype.
T T
T
t
Mexican Grey Wolf Population of Rural New Mexico, 1880-1900
1880 1882 1884 1886 1888 1890 1892 1894 1896 1898 1900
YEAR
POPULATION
150
140
130
120
110
100
90
80
70
60
50
40
Decomposers
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