Miami Senior High School



EOC Review

❖ (N.1.1) The nature of science.

➢ Scientific ideas are testable.

➢ Scientific knowledge is always changing as new technologies are invented and new pieces of evidence come to light.

➢ A scientific theory is a well-tested explanation. It may be changed or ultimately discarded if new evidence disproves it.

➢ A scientific law is a well-tested description.

➢ Scientific theories DO NOT become laws.

➢ The Scientific Method

▪ The Scientific Method is a series of steps taken during a scientific exploration.

▪ The problem or purpose is the question you are trying to answer.

▪ The hypothesis is an inference or prediction (What you believe the answer to the problem is). Based on prior knowledge.

▪ The actual experimental procedures must be designed to test the hypothesis.

▪ An experiment must be controlled, meaning that all conditions in the experiment must be kept the same except for the independent (manipulated) variable.

• The independent (manipulated) variable is the one factor being changed in the experiment. It is normally what is being tested.

• The dependent (responding) variable changes as a result of the independent variable. It is normally what is being recorded.

• A control is a part of the experiment where the independent variable is not added. Or it is the “normal” or “standard” conditions that have not been manipulated. Used as a comparison to the other parts of the experiment.

▪ Data can be in the form of graphs, tables, labeled drawings, descriptions, etc., depending on what type of information is being observed.

• Experimental error can be minimized if many trials are done.

• Remember Mr. Dry Mix: The Dependent or Responding variable on the Y-axis. The Independent or Manipulated variable on the X-axis.

▪ Data must be analyzed in order to answer the problem and determine whether the hypothesis has been supported or not.

▪ Scientists publish their experiments for peers to review and retest.

▪ Scientific experiments and data analysis must be free of bias.

❖ (18.1) Biochemistry

➢ Macromolecules are very large molecules. Some are polymers made up of many repeating smaller molecules called monomers.

➢ Carbohydrates (polysaccharides)

▪ Chains of simple sugars (monosaccharides).

• The monomers, simple sugars, are rings of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1:2:1.

▪ Organisms use them as their main source of energy. Can also be used for structural purposes.

➢ Lipids

▪ A glycerol molecule combined with chains of fatty acids. Not a polymer.

• Glycerol composed of carbon, hydrogen, oxygen.

• Fatty acid chain formed from carbon and hydrogen.

▪ Used to store energy. Important component of cell membranes. Can also function to cushion organs and provide insulation to the organism. Many steroids (chemical messengers) are lipids.

➢ Nucleic Acids

▪ Chains of nucleotides.

• The monomers, nucleotides, are made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

• The sugar of one nucleotide bonds to the phosphate of the next nucleotide in a chain.

▪ Store and transmit hereditary, or genetic, information.

➢ Proteins.

▪ Chains of amino acids.

• The monomers, amino acids, contain an amino group (-NH2) on one end and a carboxyl group (-COOH) on the other end. The R group is different in each amino acid.

• Proteins coil up in a specific shape that determines its function. If it is not the correct shape, it won’t function properly (if at all).

▪ Many diverse functions such as controlling the rate of reactions, regulating cell processes, forming important cellular structures, transporting substances into or out of a cell, and helping to fight diseases.

• Enzymes are proteins that speed up reaction rates by lowering activation energy.

□ Activation energy is the energy required to start a chemical reaction.

• Factors that affect enzymes:

□ Concentration: The more enzymes there are in a reaction, the faster the reaction will go. The fewer enzymes, the slower the reaction.

□ pH: Large changes in pH can denature an enzyme (destroy its shape) rendering it useless.

□ Temperatures that are too high can denature enzymes.

❖ (18.12) Water

➢ Composed of 2 hydrogen atoms and one oxygen atom. (H2O)

➢ Polar molecule. Has one side that is slightly positive and the other side is slightly negative.

▪ The side with the oxygen is more positive and the side with the hydrogen is more negative because oxygen is a bigger atom than hydrogen and attracts more electrons.

▪ Because of its polarity, it easily makes hydrogen bonds with other water molecules (cohesion) and with other types of molecules (adhesion).

• Hydrogen bonds are the attraction of the slightly positive hydrogen side of a polar molecule to the slightly negative side of another polar molecule.

• Cohesion is the attraction of like molecules.

• Adhesion is the attraction of two different molecules.

➢ Its cohesive ability causes surface tension on water, which some organisms use to their advantage (such as walking on it) and allows water to go up the vessels in plants.

➢ Its many hydrogen bonds with other water molecules make water less resistant to changes in temperature, affecting the temperature of the land around it.

▪ It takes a long time to break the many hydrogen bonds in water when it is heated as well as to reform them when cooled.

➢ As water gets cooler, it becomes more dense and sinks. However, due to its shape, as it freezes, it becomes less dense. Therefore ice forms at the top of lakes and rivers, allowing aquatic organisms to continue to live in the liquid water below. The change in density of warmer and cooler water, causing it to rise and sink, also controls many of the nutrient-carrying currents that affect food webs and climate all over the world.

➢ Many substances can dissolve in water (universal solvent).

▪ Its versatility as a solvent allows it to be part of most of the solutions in the cells (and bodies) of all living things.

❖ (14.1) Cell Theory

➢ Cells are the basic unit of life.

➢ All living things are composed of cells.

➢ Cells arise from pre-existing cells.

➢ Earlier ideas:

▪ Before the microscope, cells were unheard of. Even after discovery, it took many years to understand that cells could be found in all living organisms.

▪ People used to believe in spontaneous generation, where living things could arise from non-living matter.

❖ (14.3) Cell Structure and Function

➢ Organelles and cellular structures.

▪ Cell membrane (plasma membrane) surrounds the cell and is semi-permeable (only allows certain substances to pass through).

▪ Cell wall surrounds the cell membrane. Provides extra support and protection. Found in plants, fungi, some protists, and bacteria.

▪ Cytoplasm is the liquid inside of the cell in which everything suspends. Many cellular activities occur here.

▪ The nucleus contains the cell’s DNA in the form of chromatin (DNA wrapped around histone proteins). The nucleus is surrounded by a double membrane (nuclear envelope) full of pores.

▪ The nucleolus is found inside the nucleus. It produces ribosomes.

▪ Ribosomes make proteins. (Where translation occurs during protein synthesis).

▪ The endoplasmic reticulum produces molecules, such as proteins and lipids.

• The rough endoplasmic reticulum contains many ribosomes and is the site of most of the protein synthesis of the cell.

• The smooth endoplasmic reticulum does not contain ribosomes and is the site of many chemical reactions (such as the detoxification of the cell), and the production of other molecules (such as lipids).

▪ Microtubules and microfilaments are small tubes and threads, respectively, which make up the cell’s cytoskeleton. They give the cell support, allows it to move, and moves things inside the cell.

▪ Vacuoles store material.

▪ Mitochondria release the energy stored in glucose and place it in ATP molecules. This occurs during cellular respiration.

▪ The Golgi apparatus receives molecules from the endoplasmic reticulum, modifies them, and ships them out in vesicles to other parts of the cell, or out of the cell.

▪ Chloroplasts absorb the sun’s energy and stores it in sugars produced during photosynthesis.

▪ Lysosomes contain digestive enzymes that can break apart material in the cell for easier removal, or to recycle its parts.

▪ Flagella are whip-like tails that allow cells to swim or to move around material that surrounds it. Not all cells have this.

▪ Cilia are short hairs that allow a cell to swim or to move around material that surrounds it. Not all cells have this.

➢ Plant cells versus animal cells

▪ Plants have chloroplasts and a cell wall. Animal cells don’t have either.

▪ Plants have a large vacuole filled with water. Animal cells have many smaller vacuoles that store a variety of substances.

▪ Plant cells don’t have lysosomes (although some have something similar) while animal cells do.

▪ No plant cells contain cilia, although some animal cells do.

▪ Some plant cells and some animal cells contain flagella.

➢ Eukaryotes versus prokaryotes.

▪ Eukaryotes have a nucleus. Prokaryotes do not. The DNA in a prokaryote floats in the center of the cell, while plasmids (small, simple, circular pieces of DNA) float around in the cytoplasm. Eukaryotes do not have plasmids.

▪ Eukaryotes are bigger and much more complex than prokaryotes.

▪ Only bacteria are prokaryotes. All other organisms are eukaryotes.

▪ Eukaryotes contain organelles/cell structures that bacteria don’t. The organelles that they have in common are the cell membrane, cytoplasm, ribosomes, and flagella.

▪ Eukaryotic organelles are all surrounded by at least one membrane. Prokaryotic organelles are not membrane-bound.

➢ Transport of molecules across a cell membrane.

▪ Diffusion is the movement of molecules from where there is a higher concentration of that molecule to where there is less. This continues until equilibrium is reached (the concentration of the molecule is the same on both sides).

• The diffusion of one type of molecule does not affect the diffusion of other molecules.

▪ Osmosis is the diffusion of water molecules through a semi-permeable membrane (from where there is more water to where there is less water).

• If a cell is placed in a solution that has an extreme concentration gradient, equilibrium will not be reached.

□ If the solution has an extremely large number of solutes (and therefore less water), the cell will lose water too quickly and shrivel up.

□ If the solution has an extremely small number of solutes (and therefore more water), the cell will gain water too quickly and explode.

▪ Facilitated diffusion is the diffusion of molecules into and out of a cell through protein channels.

▪ Passive transport is the movement of molecules across a membrane without the need for energy, such as with diffusion, facilitated diffusion, and osmosis.

▪ Active transport is the movement of molecules across a membrane requiring the use of energy. Examples include protein pumps (where molecules need to be pumped from low concentration to high concentration, which is the reverse of diffusion), and cellular movement where the cell has to change its shape to engulf particles (endocytosis) or to excrete particles (exocytosis).

▪ The cell membrane is mostly made up of lipids that are hydrophobic (water-hating). On one side of the lipid is a phosphate molecule which is hydrophilic (water-loving). Only lipid-soluble molecules and any molecule that is very small, uncharged, and non-polar can pass through the membrane by diffusion/osmosis. All other molecules must go in/out through a membrane protein channel, which are specific to certain molecules. Or the cell can engulf and release substances by changing the shape of its cell membrane.

❖ (18.9) Photosynthesis and Cellular Respiration

➢ Photosynthesis and cellular respiration are reverse processes. The reactants of one are the products of the other.

▪ Photosynthesis uses sunlight, carbon dioxide, and water to make sugars (glucose) and oxygen. (Sunlight + CO2 + H2O ( C6H12O6 + O2)

▪ Cellular respiration uses sugars (glucose) and oxygen to make ATP, carbon dioxide, and water. (C6H12O6 + O2 ( ATP + CO2 + H2O)

➢ The purpose of photosynthesis is to make “food” for the plant in the form of glucose, which stores energy. It also makes other sugars needed by the plant.

➢ The purpose of cellular respiration is to take the energy stored in glucose (in food) and convert it into ATP. ATP can readily release energy needed for chemical reactions.

▪ ATP is a small molecule that quickly provides energy for all cellular processes. It releases energy by breaking the bond between its second and third phosphate groups, forming ADP. ATP is regenerated when a phosphate group is added to ADP and the energy (from glucose) is stored in the bond.

➢ Only plants (some protists and some bacteria) photosynthesize. All organisms use cellular respiration to make ATP.

➢ Because cellular respiration requires oxygen, it is considered aerobic respiration. When there is not enough oxygen, cells go through anaerobic respiration (fermentation) to produce ATP for a short period of time. It doesn’t produce much ATP, so most complex organisms can’t keep this up very long. Fermentation produces waste products such as lactic acid in animals and bacteria (lactic acid fermentation), and carbon dioxide and alcohol in plants and yeast (alcoholic fermentation).

❖ (16.17) The Cell Cycle

➢ Interphase: The period of time between cell divisions.

▪ Gap 1 (G1): Normal cell activity and growth. DNA is in chromatin form (DNA wrapped around proteins)

▪ Synthesis (S): DNA replication.

▪ Gap 2 (G2): Final preparations for cell division.

➢ Mitotic (M) Phase: Cell division. Used to make identical copies of a cell.

▪ Mitosis: Division of the nucleus.

• Prophase: DNA condenses into chromosomes (with sister chromatids connected by a centromere), nuclear envelope disappears, spindle forms (made up of centrioles and microtubules).

• Metaphase: Chromosomes line up in the middle of the cell (metaphase plate). Microtubules attach to the centromeres on the chromatids on either side.

• Anaphase: Spindle fibers pull sister chromatids apart taking each copy to opposite sides of the cell.

• Telophase: Nuclear envelopes form around each set of chromosomes, spindle breaks apart, and DNA uncoils back into chromatin.

▪ Cytokinesis: Cytoplasm divides, and the cell splits into 2 identical cells. Often overlaps with Telophase, but they are two distinct phases. Cytokinesis is NOT part of mitosis.

• In animal cells, the cell membrane pinches in (forming a cleavage furrow) until it meets in the middle and splits the cells. In plant cells, a new cell wall needs to be added between the two new daughter cells (at the cell plate) for separation to occur.

• After cytokinesis, the two daughter cells begin the cycle again in G1 of interphase.

➢ Meiosis. Takes the place of Mitosis for the production of gametes (sex cells). Occurs after interphase in a diploid germ cell.

▪ Meiosis I: Prophase I, Metaphase I, Anaphase I, and Telophase I. Same as Mitosis, except:

• In Prophase I, homologous chromosomes pair up and crossing over occurs.

□ Crossing over is the process by which homologous chromosomes (chromosome pairs) randomly exchange genes. Crossing over occurs differently each time.

• In Metaphase I, homologous chromosomes line up in pairs down the middle of the cell, instead of all in one line.

• In Anaphase I, homologs are separated (instead of chromatids). The way they separate is completely random (law of independent assortment). The chromatids are still together.

• In Telophase I, the chromosomes do not condense.

• After cytokinesis, the two daughter cells (which are now haploid, but with duplicated DNA) both go straight to Meiosis II. There is no interphase between the two meiotic divisions.

▪ Meiosis II: Prophase II, Metaphase II, Anaphase II, and Telophase II. Same as Mitosis, except that the cells are haploid instead of diploid. Both daughter cells go through Meiosis II.

• Haploid cells have only one set of chromosomes. Diploid cells have two sets of each chromosome.

• After cytokinesis, the 4 resulting daughter cells do not return to interphase. They are used as gametes or they are reabsorbed by the body.

➢ Differences between Mitosis and Meiosis

▪ Mitosis is used in asexual reproduction (no genetic variation). Meiosis produces gametes for sexual reproduction (produces genetic variation).

▪ Mitosis produces 2 genetically identical, diploid daughter cells. Meiosis produces 4 genetically different, haploid cells.

▪ Mitosis has one division, while Meiosis has two.

➢ Mutations in the DNA that control the cell cycle could cause cells to continue to divide indefinitely. This leads to the formation of tumors (mass of cells that continues to grow). Benign tumors don’t spread. Malignant (cancerous) tumors can spread to other parts of the body.

❖ (16.3) Nucleic Acids

➢ DNA structure is a double-stranded nucleic acid. The two strands are connected by their complementary bases, and are twisted together in a double helix shape.

➢ DNA Replication (during the S phase of Interphase of the cell cycle)

▪ DNA helicase unwinds the DNA molecule and separates the two strands.

▪ DNA polymerase connects free-floating nucleotides to the nucleotides on the original strands with the corresponding base, forming a new strand.

• Base pairings: Adenine bonds with Thymine (A-T). Guanine bonds with Cytosine (G-C).

▪ Each new, identical DNA molecule (each with an old and a new strand) winds back up into a helix. These are the sister chromatids, connected by their centromeres, that will eventually be separated in anaphase of mitosis.

➢ Protein synthesis

▪ Transcription is the process by which the DNA code is copied as RNA (RNA is a single-stranded nucleic acid. The sugar in DNA and RNA is different). This occurs in the nucleus.

• DNA unwinds and the two strands separate.

• RNA polymerase binds free-floating RNA nucleotides to the nucleotides on the DNA template strand (only) with the corresponding base, making a copy of the DNA code in the form of mRNA (messenger RNA).

□ RNA does not have the base Thymine. It is replaced by Uracil, which binds with Adenine on the DNA (A-U).

• mRNA separates from the DNA and leaves the nucleus. The DNA strands come back together and wind back up into a helix.

▪ In Translation, ribosomes use the mRNA copy to make proteins. It occurs in the ribosomes.

• The mRNA takes the DNA message to the ribosome (made up of protein and rRNA – ribosomal RNA) which then reads the message.

• The code is read by groups of 3 nucleotides (codons) found on the mRNA.

• When a codon is in the ribosome’s binding site, a tRNA (transfer RNA) with the matching base pairs (anticodons) will bind to the mRNA’s codon. Each tRNA carries the correct amino acid with which to build the protein.

• When the ribosome moves to the next codon, and the next matching tRNA binds to it, the amino acids from the adjacent tRNAs bind together and the previous tRNA leaves. Step by step, a protein chain is being formed.

• When the ribosome reaches the stop codon, the ribosome, rRNA and newly-formed protein separate. The protein then folds into a particular shape.

▪ The codon table contains all possible codons and the amino acids that they code for. Some amino acids are coded for by more than one codon. Remember that to use the codon table you look at the codons on the mRNA strand (the tRNA has anticodons).

➢ Due to common ancestry and inheritance, DNA is universal to all organisms and can be used to make the same proteins.

❖ (16.1) Genetics

➢ Alleles are different versions of a trait.

➢ Most organism have 2 of every allele (one from each parent). The combination of alleles for each trait is the organism’s genotype.

▪ A homozygous genotype indicates that both alleles are the same.

▪ A heterozygous genotype indicates that both alleles are different.

➢ A phenotype is the trait that is expressed in the organism. Not all of the alleles in an organism’s genotype are expressed in its phenotype.

➢ Mendel’s Principles:

▪ Dominance: Some alleles are dominant over other (recessive) alleles, and mask them in heterozygous individuals.

▪ Segregation: Alleles from homologous chromosomes separate into different gametes during Meiosis.

▪ Independent Assortment: Segregation occurs randomly each time Meiosis occurs. The way alleles segregate does not affect the segregation of other genes.

➢ Punnett squares can be used to predict the probability of passing on inherited traits.

▪ In a monohybrid cross (to predict the inheritance of one trait), the alleles of one parent are placed along the top, and the other parent’s alleles are placed along the side. In dihybrid crosses (used to predict the inheritance of 2 traits together), combinations of the parents’ alleles for both traits are used.

▪ The boxes inside the square are filled in to find the probability of possible genotypes and their phenotypes. Results can be expressed as fractions, percentages, or ratios.

➢ Codominance: Two alleles are both dominant and both are expressed in the phenotype in heterozygous individuals.

➢ Incomplete dominance: Neither allele is completely dominant over the other. In heterozygous individuals the phenotype shows as an intermediate of the two alleles.

➢ Multiple alleles: There exist more than 2 alleles for a trait.

➢ When genes are found on the sex chromosomes, they are sex-linked (or X-linked). X-linked traits are not found on the Y chromosome. The X and Y chromosomes need to be included when completing the Punnett square.

▪ Males are XY and females are XX.

➢ Polygenic inheritance: One phenotype is determined by a combination of more than 1 pair of genes. This leads to greater variation in phenotypes.

❖ (15.8) Origins of Life

➢ Many ideas.

▪ One of the most popular is chemical evolution: In the presence of water, certain gases, and enough energy, organic molecules spontaneously form. This idea was first tested by Miller and Urey.

➢ Once organic molecules formed in the early seas, it is believed that they reacted with clay on the sea floor and formed bubbles with semi-permeable membranes. Those bubbles began to take in other molecules and began metabolizing and dividing. These cell-like structures eventually gained genetic material and the first cells (first forms of life) appeared. The first life form was most likely a prokaryotic (bacterial) cell that could survive in the harsh conditions of the early Earth. It was probably anaerobic. Aerobic cells probably did not evolve until cells began to photosynthesize, releasing oxygen into the atmosphere and killing off the anaerobes.

➢ The ideas of how life began on this planet are deductions based on observable evidence and tested criteria in a laboratory environment. As a result of these experiments, it has been proven that these events are possible. However, it is impossible to know if these are the events that actually did occur.

❖ (15.1) Theory of Evolution

➢ Well-supported explanation of how organisms change over time in order to adapt to changing environments.

➢ The work of scientists have aided in the formation of this theory.

➢ Evidence

▪ Fossil record shows how organisms change over time with a changing environment. It shows links (such as intermediate species) between living and extinct organisms.

▪ Comparative anatomy looks at the body structures of different species and notes similarities among them.

• Some organisms have similar basic structures (homologous structures) that have changed to adapt to different environments. Shows common ancestry. In some cases, modern organisms have useless structures (vestigial structures) that indicate their evolution from an ancestor that needed it. The original, ancient ancestor population must have split and each group evolved separately. This caused their structures to change to adapt to the new, different environments the descendants went to.

• Some unrelated organisms show similar adaptations to similar environments, indicating that organisms change to adapt to their environments. Their ancestors came from different populations, but because they began living in a similar environment, they evolved similar adaptations.

▪ Comparative embryology shows how similar vertebrate embryos are during the early stages. Leads to idea of common ancestry. The more similar the embryos, the more closely related the organisms are.

▪ Biogeography is the study of where organisms live now and where they and their ancestors lived in the past. Distribution patterns show how organisms adapted to different environments as the environments changed, and as populations moved from one place to another.

▪ The way all organisms’ bodies function in similar ways, chemically, shows that all living things evolved from a common ancestor. Universal DNA is a particularly strong example. Comparing molecules such as DNA and proteins can help determine how closely related organisms are to each other. The more similarities in the moleucles, the more closely related the organisms are.

▪ Evolutionary change can be observed in rapidly reproducing organisms such as bacteria, which can evolve resistance to antibiotics at a rapid rate.

➢ Evolutionary patterns:

▪ Members of one original population can migrate and begin populations in many other environments. Each new population can then evolve separately, but all have a common ancestor. (Divergent evolution)

▪ Members of different populations can migrate to the same environment and begin to evolve in similar ways. They will end up having similar adaptations even though they are not closely related. (Convergent evolution)

▪ Members of two populations that have close relationships may evolve together in order to maintain those relationships. (Co-evolution)

▪ There is fossil evidence showing that evolution occurs gradually and continuously as the world changes (gradualism). However, there is also evidence of long periods where there is no evolution occurring interrupted by relatively short periods of “rapid” speciation (new species appearing through evolution). This is called punctuated equilibrium.

➢ Hominid evolution.

▪ From the earliest human-like species to the modern human, there have been some basic trends in evolutionary advances.

• Increasingly upright posture allowing for farther sight across plains, and freeing of hands for other uses.

• Fully opposable thumbs and dexterous fingers, allowing for the production of more sophisticated tools, weapons, and clothing.

• Increasingly larger brain cases in the skull and smaller faces. Indicates an increase in brain size, allowing for more intelligence. Modern humans have the largest brains compared to body size of any animal ever in existence. We have highly sophisticated culture. Smaller faces indicate a change in diet from a more herbivorous diet, to omnivorous diet. The discovery of fire and how to manipulate it could have been used to soften food. That is another possible reason for the trend of a decrease in face and teeth size.

❖ (15.13) Natural Selection:

➢ The main process by which evolution is believed to occur.

➢ In order for natural selection to occur, there must be variation in the population and a change in the environment. The organisms with the adaptations for the new environment survive and reproduce the adaptation, and the ones that do not have the adaptation do not survive long enough to reproduce. Over time, the population will be composed more and more of the organisms with the adaptation and less and less of those without.

➢ Mutation and genetic recombination (in Meiosis and through sexual reproduction) provide the variety in populations needed for natural selection to occur. The more variation is found in a population, the better chance there is for some members of the population to survive an evolutionary change. Organisms CANNOT change themselves to adapt to a new environment.

▪ Any mutation or change that occurs on the organism during its lifetime cannot be passed on to offspring, and so does not affect evolution.

➢ Genetic drift (the change in allele frequency of a population due to a random event) can lead to evolutionary change. The same is true of gene flow from one population to another, and non-random mating, where certain characteristics are chosen over others, even though it might not be an adaptation for survival (also called sexual selection).

▪ Allele frequency is the amount of times a particular allele is found in a population. Changing frequencies can indicate evolution in a population.

❖ (15.6) Classification:

➢ The grouping of organisms into groups that contain similarities in structure, function, and evolutionary relationships.

➢ Three Domains (the most general classification group).

▪ Archaea: Unicellular prokaryotes (simple cells with no nucleus). Their cell walls do NOT contain peptidoglycan. They may be autotrophs or heterotrophs. They are usually found in extreme environments. (Archaebacteria is the only kingdom) These are ancient, primitive cells very similar to what the first living things were probably like. They tend to live in very extreme environments.

▪ Bacteria: Unicellular prokaryotes (simple cells with no nucleus) with cell walls that contain peptidoglycan. They may be autotrophs or heterotrophs. (Eubacteria is the only kingdom)

▪ Eukarya: Eukaryotes (complex cells with a nucleus).

• Eukaryotic kingdoms

□ Animalia: Multicellular heterotrophs that freely move from one place to the next at some point in their life cycle. Their cells do not contain cell walls.

□ Plantae: Multicellular autotrophs (photosynthetic) that grow in one spot (attached by roots or root-like structures). Cell walls made of cellulose.

□ Fungi: Mostly multicellular heterotrophs that absorb nutrients through filaments. Do not freely move. Cell walls made of chitin.

□ Protists: Mostly unicellular organisms. Are placed in this kingdom if they don’t fit in any of the other 3. Very diverse kingdom. Some are plant-like, some fungus-like, and some animal-like.

➢ Organisms are often classified based on their evolutionary relationships, showing which species evolved from which other, which broke off and evolved in a different direction, and what new characteristics (derived characteristics) differentiate an older species from a newer species. Cladograms are often used to show these relationships.

➢ The classification of organisms has changed over time as taxonomists discover new evidence about species, or due to disagreements about placement of some species. The classification system itself has also changed over time, and continues to change.

❖ (14.7) Plants

➢ Plant organs

▪ Roots absorb water and nutrients from the soil. The tip is protected by a root cap. Root hairs all over the root increase surface area for greater absorption.

▪ Stems produce leaves, branches, and flowers; they hold the plant up to the sun, and transport substances throughout the plant.

▪ Leaves are the sites of gas exchange, and where the majority of photosynthesis takes place. Water evaporates from the leaves.

• Under the leaves are holes (stomata) that allow for gas exchange and the evaporation of water.

• Guard cells open and close the stomata, controlling how much O2 and CO2 gas is let in/out, and how much water is allowed to evaporate.

▪ Flowers contain the sexually reproductive organs of flowering plants.

• Flower petals are often brightly colored and/or give off a scent that attracts pollinators.

• Pollen (which contains the plant’s sperm) is produced by the anther. It is held up by the filament which allows it to be easily accessible to pollinators and/or the wind. Together, the anther and filament are called the stamen.

• The pollen reaches the female structures (pistil or carpel) by wind or pollinators. The tip of the pistil is a sticky structure called the stigma which catches the pollen. A pollen tube is formed down the style through which the sperm travels to the plants’ ovary. The ovary contains the ovules.

• The sperm fertilizes the egg cells in the ovary and produces seeds. Each seed contains an embryo and food source protected by a hard outer covering.

• After a flowering plant is fertilized, the petals fall off and the seed-containing ovary swells into a fruit.

• The fruit helps disperse the seeds. If the seeds are eaten by other organisms, after digestion they may fall on the ground in feces. Seeds that are not eaten fall on the ground. If the fruit is not eaten, it falls on the ground and rots, freeing the seeds. Some fruits are adapted to sticking on the fur/feathers of other organisms, can float on water in order to move to other locations, or can be dispersed by the wind.

▪ Cones are the sexually reproductive organs of coniferous plants. Pollen from the male cones reaches the female cones by wind, where the egg cells are fertilized, forming seeds. The winged seeds are dispersed by the wind.

➢ Tissues

▪ Meristematic tissue is where cells are actively dividing and from where the plant grows. Found at the tip of the stems and roots, and in buds.

▪ Ground tissue produces and stores sugars, and helps support the plant. It’s found between the dermal and vascular tissue.

▪ Dermal tissue is the protective outer covering in plants.

▪ Cambium: Causes plants to grow in width by adding vascular tissue.

▪ Vascular tissue allows water and nutrients to flow efficiently to all parts of the plant, and helps support its body. It’s found in the middle of the plant. Not found in mosses or their relatives.

• Phloem transports sugars.

• Xylem transports water and nutrients.

➢ Processes

▪ Photosynthesis is the process by which plants take in the sun’s energy (through the leaves, or any green part of the plant), CO2 (through the stomata in the leaves), and water (through the roots) to produce O2 (released through the stomata in the leaves) and high-energy sugars, such as glucose. The glucose then travels to the other parts of the plant through the phloem.

▪ Cellular respiration is the process by which plants use the glucose they made in photosynthesis, along with O2, to make CO2, water, and energy in the form of ATP.

▪ Transpiration is the evaporation of water from a plant’s leaves (stomata). As water evaporates, the remaining water column in the xylem moves up due to its cohesive nature and its adhesion to the xylem walls. In this way, water moves up through the plant.

▪ Alternation of generations. The life cycle of plants involves alternating sexual (producing gametes through meiosis) and asexual (producing spores through mitosis) reproduction.

❖ (14.26) Brain.

➢ Major regions:

▪ Cerebrum is the top portion of the brain.

• Lobes: (Fat Turkey Pig Obesity – Frontal Temporal Parietal Occipital)

□ Frontal lobe is located at the front of the brain.

□ The parietal lobe is in the middle of the brain.

□ The occipital lobe is at the rear.

□ The temporal lobes are located on either side.

▪ Cerebellum is located at the rear bottom of the brain, below the cerebrum.

▪ The brain stem connects the brain to the spinal cord. The top is called the pons. The bottom is the medulla oblongata.

❖ (14.36) Factors that affect the cardiovascular system

➢ Blood pressure is required to move blood around the body. It is caused by the pumping of the heart and the constricting of blood vessels.

➢ If blood pressure becomes too high the heart can become overworked and may eventually stop beating. Blood vessels may also tear.

➢ Blood volume

▪ Increased water in the blood increases blood pressure but slows blood flow. Decreased water in the blood leads to decreased blood pressure and blood flow.

▪ Increased number of blood cells (high viscosity) increases blood pressure, but decreases blood flow.

➢ Arterial resistance increases blood pressure and speed of blood flow, but the amount of blood flowing through the smaller sized vessels is less. The reverse is true if there is less resistance.

▪ Atherosclerosis (or arteriosclerosis) can cause arterial resistance to increase by causing blood vessels to become stiff, and clogged with plaque. If the vessel is completely clogged up, no blood can pass through.

▪ A blood clot in the brain can cause a stroke.

➢ Some diseases cause problems with circulation. The amount of blood that passes through depends on how the disease affects the viscosity of the blood, shape of the blood cells, and size and elasticity of the vessels.

➢ Exercise causes the heart to pump faster, increasing the blood pressure, the speed of the blood flow, and the amount of blood moving through the blood vessels.

❖ (16.13) Human Reproductive System.

➢ Male Anatomy

▪ The testes produce sperm. They are located in the scrotum, an external sac, which keeps the temperature a little lower than the body’s temperature (important for proper sperm development).

▪ After production, sperm move into the epididymis where they mature and are stored until needed.

▪ The vas deferens moves sperm from the epididymis to the urethra.

▪ Seminal vesicles and prostate gland produce a nutrient-rich fluid called seminal fluid, which nourishes the sperm and protects them from the acidity of the female reproductive tract.

▪ The sperm and seminal fluid mix in the prostate gland. The combination of sperm and seminal fluid is the semen which passes through the urethra and is released through the penis during ejaculation.

➢ Female anatomy

▪ Ovaries produce egg cells (ova).

▪ Every month, an ovum is released from one ovary into the oviduct (fallopian tube), where it may or may not be fertilized.

▪ If an ovum is fertilized, the embryo will implant itself into the wall of the uterus, where it will finish its development.

▪ Sperm enters the female’s reproductive tract through the vagina. It then passes through an opening called the cervix, into the uterus, and then the fallopian tubes where fertilization can occur if there is an ovum present.

➢ Pregnancy and development

▪ Fertilization occurs in the fallopian tubes, producing a fertilized egg (zygote), now also referred to as an embryo.

▪ Zygote undergoes mitosis, eventually forming a hollow ball of cells called a blastocyst which attaches itself to the uterine wall and begins to grow into the tissues of the mother.

▪ The blastocyst cells begin to differentiate. Some cells will become the body of the embryo, the others will become tissues that support and protect the embryo.

▪ The placenta connects the mother and embryo and acts as the embryo’s organ of respiration, nourishment, and excretion. Oxygen and nutrients diffuse from the mother’s blood to the embryo’s/fetus’s blood. The wastes the baby produces passes through the placenta to the mother’s blood to be excreted. The embryo/fetus is connected to the placenta by the umbilical cord.

▪ The embryo (and later, the fetus) develops within the amniotic sac filled with amniotic fluid that cushions and protects it.

▪ After 8 weeks of development, the embryo is called a fetus. Most of the major organs and tissues are fully formed at this time. It may begin to move and show signs of reflexes.

▪ During months 4 to 6, the tissues of the fetus become more complex and specialized and begin to function more efficiently. Bone begins to replace cartilage.

▪ The last three months before birth, the organ systems of the fetus mature, and it grows in size and mass. The organs undergo a series of changes that prepare them for life outside the uterus.

▪ During pregnancy, the cervix is tightly closed. At the time of birth, the cervix opens, and involuntary muscle contractions push the baby, headfirst, through the cervix and out through the vagina.

➢ Many different hormones work to regulate the male and female reproductive organs, as well as pregnancy and birth.

❖ (14.52) Immune System

➢ Fights off diseases and pathogens, and heals injuries.

➢ Immune responses

▪ Specific: Responds to specific pathogens. Pathogens have unique antigens (proteins that label them as foreign). The body produces B cells with antibodies that bind to specific antigens and allow T cells to find and destroy the pathogens. The body then produces memory cells, so if the pathogen ever enters the body again, the immune response will be much faster and illness will not occur.

▪ Non-specific: Responds to all pathogens.

• The skin is the first line of defense, which keeps pathogens from entering the body.

• Tears, sweat, and other secretions destroy pathogens or remove them from the body.

• Fever results from the increased activity of the body while fighting off an infection. The increase in temperature speeds up chemical reactions in the body, making the immune response faster, and helps inhibit and/or destroy the pathogen. Fever that is too high, however, can cause enzymes to denature and the body to overheat, possibly even causing death.

• Inflammatory response: When the skin is injured, the body increases blood flow to the injured region (causing swelling and redness) in order to bring in cells that can stop the bleeding and repair the injury. White blood cells also arrive to fight off any pathogens entering the body through the injury site.

• Interferons slow down viral activity allowing the body more time to react and fight off the virus.

➢ Medications/treatments:

▪ Vaccines: A destroyed or weakened pathogen, most commonly a virus, is injected into the body, causing a specific immune response. The memory cells produced keeps the individual from getting sick if the active pathogen ever infects his/her body.

▪ Antibiotics, used only against bacterial infections, destroy the cell wall of the bacteria. Each type of antibiotic works against bacteria with specific cell wall structures. They do NOT work on viral infections!! (Viruses don’t have cells). They also don’t harm the human body because humans don’t have cell walls.

▪ Antiviral medications are available for some infections. They slow down/interrupt viral activity.

➢ Certain genetic factors, diseases, and environmental factors can decrease the efficiency of the immune system.

➢ Keeping high sanitation standards (cleaning, washing hands, vaccinations, cooking food correctly, etc.) keeps individuals, and the society as a whole, healthy.

❖ (17.9) Ecology.

➢ The study of the interdependence between organisms and between them and their environments.

➢ Food webs

▪ Illustrate the flow of energy through an ecosystem. Flows from one organism into the organism that consumes it. This is depicted by the use of arrows.

▪ Producers produce all the energy needed in the ecosystem. Consumers eat producers and/or other consumers to get their energy. Decomposers break down dead organisms and wastes and receive their energy from that organic matter.

▪ According to an ecological energy pyramid, energy decreases as it goes up trophic (feeding) levels. Therefore, there are less higher-level organisms than lower-level.

▪ Changes in a food web affect other organisms in the ecosystem. The organisms lower on the food web have the greatest effect on other organisms, because they form the base of the ecosystem on which other organisms depend.

▪ Food webs that are more diverse have greater stability because consumers have more food choices to rely on if one or more of their food sources decreases.

➢ Biogeochemical cycles

▪ Carbon cycle: Carbon dioxide in the air is absorbed into producers through photosynthesis to make sugars and other carbon-based compounds. Consumers eat the organic carbon in plants and other consumers. Decomposers acquire their organic carbon by decomposing other organisms. All organisms release carbon dioxide as a waste product of cellular respiration back into the atmosphere. The burning of fossil fuels and other organic material, as well as some geological events, can also add carbon dioxide to the atmosphere.

▪ Water cycle: The sun evaporates water from bodies of water, adding water vapor to the atmosphere. As water vapor rises, it cools, condenses, and falls back to earth as precipitation. The water is absorbed by plants (through their roots) and taken in by consumers (by drinking it or by eating producers and/or other consumers). Decomposers receive their water from the organic matter they break down. Plants release water back into the atmosphere through transpiration. Other organisms release water through liquid wastes. Water not used by organisms runs off into bodies of water, or is absorbed into the ground as sources of groundwater.

❖ (17.5) Population Ecology

➢ Abiotic factors (non-living parts of the environment) determine what biotic factors (living organisms) live in an environment.

▪ Abiotic factors in terrestrial environments include temperature, amount of sunlight, latitude, soil, etc.

▪ Abiotic factors in aquatic ecosystems include:

• Chemistry: pH, salinity, and the amount of oxygen, carbon dioxide, nitrogen, and phosphorous.

• Geography: water depth, latitude, temperature, underwater topography, proximity to land.

• Amount of light. In areas that are too deep for light to pass through, photosynthesis cannot occur. Chemosynthetic organisms can be the producers for these ecosystems.

➢ Carrying capacity is the maximum amount of organisms in a population that the environment can support. As populations become bigger, competition for space, food, water, etc. becomes greater, causing a decrease in the population. Competition lessens as populations decrease, allowing more organisms to survive and reproduce, causing the population to grow bigger. Size changes occur due to emigration, immigration, birth, death, etc.

➢ Ecosystems change

▪ Seasonal variations and climate change affect temperature, food sources, availability of water, etc.

▪ When ecosystems are damaged, they rebuild by a process known as succession. Different organisms will live there along its different stages.

• Primary succession occurs where there are no signs of any previous ecosystem, only bare rock. Not even soil is present.

• Secondary succession occurs where a previous ecosystem was damaged, and there was some part of it remaining, even if it was just soil.

➢ A reduction in biodiversity can cause populations and communities to become less stable. Less variety means less chance of survival should an important ecological change occur. Greater variety increases the chances of survival in the event of a major change.

❖ (17.20) Human Impact on Environments

➢ Reduce biodiversity

▪ Destroy habitats for industrialization and/or through pollution.

▪ Overexploitation of populations (removing too many members of the population so that they cannot maintain their numbers).

▪ Introduction of non-native species, which can disrupt native food webs.

➢ Sustainable development practices implemented to be able to continue to use populations without causing them to decrease to unsustainable numbers.

➢ Overusing nonrenewable resources (those that can only be used once, or that take too long to replace), depleting natural resources.

➢ Reforming ecological practices to increase the use of renewable resources (which are unlimited or can be replaced quickly) and limiting pollution.

❖ (16.10) Biotechnology

➢ Genetic engineering has many medical benefits, for example, when used to treat diseases.

➢ Techniques have been used to make organisms (such as plants) more resistant, easier to grow, more productive, etc.

➢ Some fear that creating organisms with new traits or new species entirely, may affect the natural process of evolution and could throw our ecosystem off-balance.

➢ There are many ethical issues attached to many of these processes, such as cloning and stem cell research.

Illustrations for EOC Review

Sugar

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Lipid

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Nucleic Acid

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[pic]

[pic]

Cell Membrane

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Eukaryotic (Animal and Plant), and Prokaryotic

[pic]

Diffusion

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Passive and Active Transport

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Meiosis

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Crossing Over

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DNA Replication

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Protein Synthesis (Transcription)

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Protein Synthesis (Translation)

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Codon Table

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Point Mutation

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Frameshift Mutation

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Chromosomal Mutations

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Cell Cycle

[pic]

Punnett Square (Monohybrid Cross)

Bb x Bb

B b

|B |BB |Bb |

|b | | |

| |Bb |bb |

Punnett Square (Dihybrid Cross)

|BbCC x bbcc |

| |BC |BC |bC |bC |

|bc |BbCc |BbCc |bbCc |bbCc |

|bc |BbCc |BbCc |bbCc |bbCc |

|bc |BbCc |BbCc |bbCc |bbCc |

|bc |BbCc |BbCc |bbCc |bbCc |

Cladogram

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Plant Organs

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Stomata and Guard Cells

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Flower Structures

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Brain Lobes

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Brain Structures

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Male Reproductive Structures

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Female Reproductive Structures

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Carbon Cycle

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Leaf Cross-Section

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Nucleotide

Base

sugar

Phosphate

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