Biology Lesson # 1 – The Microscope



Biology Lesson # 1 – The Microscope

Name: Date:

Parts of the Compound Light Microscope

• Since the invention of the microscope, scientists have been able to analyze the function and individual parts within .

• The microscope that we are using is called a microscope, which uses light focused through different lenses to form a magnified of a specimen or object.

|Part |Function |

|Body Tube | |

|Revolving Nosepiece | |

|Objective Lenses | |

|Stage | |

|Diaphragm | |

|Lamp | |

|Base | |

|Fine Adjustment Knob | |

|Coarse Adjustment Knob | |

|Stage Clips | |

|Arm | |

|Ocular Lens (Eyepiece) | |

Magnification

• A microscope can have a magnification up to (it could produce an image 20 times larger than the actual object).

• A microscope contains magnification lenses (the and lens), which when used together, allows for a larger magnification.

o For example, if the ocular lens is 10x magnification, and the highest objective lens is 40x magnification, then the total magnification is magnification of the image!

Resolution

• We can magnify an image all we want, but if the original image details are , we won’t be able to see much more when it is bigger.

• The resolution, or resolving power, is the .

Contrast

• Contrast is the .

• Scientists often use to improve the contrast of the structures they are observing under the microscope. The most common stains are methylene blue and iodine. Sometimes scientists even use dyes and then place the objects under ultraviolet (UV) light.

Electron Microscope

• An electron microscope uses a instead of , and is much more powerful than a compound microscope. Some images can be magnified 1 500 000x!

• The downside to electron microscopes is that a beam of electrons can pass only through thin slices of a sample, so only can be studied, which means that living cells (which are thicker) cannot be studied, only ones that are dead.

Biology Lesson # 2 – Animal & Plant Cells

Name: Date:

The Cell

• Cytology – the branch of biology that . It is made possible by the .

• Robert Hooke first used the word “cell” in 1663.

o He was examining under a microscope, and thought that cork had many compartments or “cells” throughout its entirety.

o He originally thought that cells were for the , but we now know today that many other things occur within cells.

• Anton van Leeuwenhoek studied simple living organisms, and thought them to be little living molecules, called “ ”

• Cell theory states that:

1. .

2. .

3.

.

• Each cell contains smaller parts called organelles, which have special functions that maintain all the life processes of the cell, including:

o

o

o

o

o

o

o

Cell Organelles

|Cell Part |Function |

|Cell Membrane |A around the cell |

| |This membrane allows different substances to move in and out of the cell, which is called . The amount of diffusion depends |

| |on the concentration of the particles on both sides of the membrane. Particles will always diffuse from . |

|Cytoplasm |A that fills the cell and surrounds the organelles, where they can stay in place or move around. |

| |It contains the required by the cell to carry on its life processes. |

|Nucleus |The of the cell (like the brain). It controls all the activities in the cell, including and . |

| |The nucleus is surrounded by the , which allows pores to transport materials in and out of the nucleus itself. |

| |The most dense area of the nucleus is called the . |

| |The nucleus contains the cell’s DNA ( ), which is bound to proteins called . |

|Centrioles |Only found in cells. |

| |Structures responsible for . |

|Vacuoles |Membrane-bound organelles that used in the cell. |

|Vesicles |Membrane-bound organelle that throughout the cell. |

|Mitochondria |The of the cell – chemical reactions occur to convert in sugar into energy that the cell can use. |

|Lysosomes |Small organelles that are filled with (proteins that speed up chemical reactions) where takes place. |

| |They also break down invading bacteria and damaged cell organelles – the in the cell. |

|Ribosomes |Small organelles where . |

|Endoplasmic |A series of interconnected small tubes that throughout the cell |

|Reticulum |ER is associated with , and have ribosomes attached to it. |

|(ER) |ER is associated with making . |

|Golgi Apparatus |Receives proteins from the ER, and for delivery throughout the cell or even outside the cell. |

|Cytoskeleton |Internal network of fibres, made of proteins, which helps . |

|Cell Wall |Only found in cells. |

| |A rigid frame around the cell that provides . |

|Chloroplasts |Only found in cells. |

| |Contain a green substance called , which uses energy from the sun to convert carbon dioxide and water into sugar and oxygen in|

| |a process called . |

Differences between Animal and Plant Cells

• Only plant cells and .

• Plants have a compared to animal cells.

• Some plant cells store energy in the form of , whereas animal cells store energy in the form of .

• Some animal cells have specialized functions, such as .

• Animal cells have which are involved in cell division, whereas plant cells do not.

Plant Cell Diagram

Animal Cell Diagram

Biology Lesson # 3 – The Life of Cells

Name: Date:

The Cell Cycle

• Cells reproduce through a continuous sequence of growth and division called cell cycles.

• The cell cycle differs in based on the different types of cells.

• The cell cycle has main stages:

A.

• This cell growth is also called , and is divided into three parts

o

o

o

B.

• This division is also called , and is the division of

• , the division of the cytoplasm and organelles, also occurs in this stage.

A Closer Look at Interphase

• In this stage, .

• DNA is in the form of (thin strands which are hard to see).

• Centrioles and DNA are replicated at this time – each .

A Closer Look at Mitosis

• Mitosis is cell division – the chromosomes and nucleus of the “parent” cell are to produce two identical “daughter” cells.

• The three main functions of mitosis are:

o - we need to increase our cellular amount to increase in size

o - to replace worn or old cells

o - sperm and egg cells go through a special type of division called to create new life.

• There are stages of mitosis. Use the acronym to remember the order.

Stage 1 –

• In this stage, (also called poles) of the cell

• appear around the centrioles

• The chromatin condenses ( ) into and are now visible.

• The chromosomes pair up to form a double strand. Where the strands join together is called the .

• The nuclear membrane and nucleolus and disappear

Stage 2 –

• At this stage, the chromosomes of the cell (called the ).

• Centrioles are now at the with spindle fibres running between them

• Each double-stranded chromosome is also attached to a spindle fibre at the centromere.

Stage 3 –

• At this stage, the chromosome pair is at the centromere, with one going to one pole, and the other going to the other pole (opposite ends of the cell).

• The chromosomes are now single stranded, and are now called .

Stage 4 –

• In this stage, the

• The spindle fibre breaks down and disappears

• The nuclear membrane starts to around the chromatids and the nucleolus reappears

• The chromatids uncoil (thin) and again.

Cytokinesis

• This occurs at the , and involves the , including organelles.

• In animal cells, the cell membrane pinches in, forming a “ ” where it will eventually split in two.

• In plant cells, a new cell wall forms between the two halves called a “ ”

Interphase (again!)

• Once the division is done, the new cells are called “ ” cells

• The daughter cells are to each other and to their original parent cell

• Each daughter cell enters a before they will also divide in mitosis.

Biology Lesson # 4 – The Death of Cells & Cancer

Rates of Cell Growth and Division

• The of cells and varies depending on the of cell.

o For example, do not undergo mitosis once they mature (which is why nerve damage is almost always ).

o , on the other hand, divide regularly, which is why cuts and scrapes heal rather quickly.

• organisms undergo rapid mitosis of cells in the areas of growth, whereas mitosis is much slower in organisms.

• If cells are more likely to be as they function, they tend to divide faster as well.

o divide fast since exposed to many chemicals during digestion.

o , on the other hand, last up to four months, because they are less likely to be damaged.

• In plants, more division and growth occurs in the meristem region (the ) compared to the .

Environmental Factors that Affect Mitosis

• The might also play a role in the rate of cell division.

• If your environment changes, mitosis will occur more rapidly in some areas of your body. For example, your blood cells would divide more rapidly in areas of , because they receive .

• In plants, the rate of mitosis changes from .

• The stem cells of plants grow more rapidly when facing away from the light, which is why plant stems the light (the opposite side is now heavier with more cells).

• decrease the rates of mitosis in certain cells to stop from growing and spreading. Other drugs stop the to stop a certain cell from functioning.

Cell Death

• The life of cells is determined by the cell cycle, but some cells die because they suffer throughout their period of growth or division.

o For example – exposure to .

o Cell death from damage is called .

• Cells can also die when they can no longer or are .

o For example – cells used to fight a viral infection. When the infection is gone, they are no longer necessary.

o This regular death of cells is called .

Cancer Cells

• A cell that divides and is called a cell. These cells develop when a change occurs in the cell that affects how the cell .

• If the DNA of the cell changes, it is called a . Some mutations occur due to:

o - commonly linked to and

o - Ultraviolet (UV) radiation is commonly linked to cancer

o - Cigarette smoke is commonly linked to cancer.

• These factors are called .

• A is a mass of cancer cells formed by abnormal rapid cell division, and there are two types:

1.

o it is

o remains in a

o causes

2.

o it is

o can to other areas of the body

o causes

• and can be used to slow or stop the effects of dividing cancer cells.

o The chemical treatment is called

o The radiation treatment is called

Comparing Normal Cells with Cancer Cells

|Normal Cells |Cancer Cells |

| | |

| | |

| | |

| | |

| | |

Biology Lesson # 5 – Specialized Cells

Regeneration

• is the process whereby a body part is or .

• The best example of regeneration is the – it can regrow amputated limbs, tails, eye lenses, and even some parts of its heart!

• This is very unique, and regeneration is in humans.

o There are a few special cases, but only the is known to naturally regenerate.

o There have been cases where have regrown if amputated.

o There have also been cases where organs were regenerated in the lab, such as a functioning .

Specialized Cells

• All cells come from pre-existing cells ( ), and all cells begin as a single cell (a ); this zygote then begins to divide and cells develop in different ways.

• We are organisms – made up of of cells.

• Not all of the cells are exactly the same – they do all have the information, but they all do jobs.

• Cells develop in different ways to perform particular functions in a process called .

• For example, animal cells may become specialized to form cells, or cells, and plant cells can specialize to form cells, cells, etc.

Stem Cells

• Unspecialized cells in the body are called – this is the very first cell we came from.

• Scientists believe that stem cells may be used to treat or by regenerating organs, since they are able to become in the human body.

• There are two types of stem cells:

1. stem cells – found in embryos

o Many stem cells before birth

2. stem cells – found in mature organisms

o Few stem cells after birth

• Stem cells are also found in plants, and they are called cells. They are found in the root tip and stems

Biology Lesson # 6 – Plants – Tissues, Organs & Systems

Name:

Definitions

• – specialized cells that group together to perform their tasks

• – is an organized group of tissues that performs a special function.

• – groups of organs that work together to perform a large body task

• – a group of organ systems making up an entire living being.

Plant Tissues

• There are types of tissues found in plants.

|Tissue Type |Description |

|1. Meristematic Tissue |Made of cells (stem cells) found the plant |

| |Responsible for growing of the plant. |

|2. Epidermal Tissue |Forms a on the leaf which is clear and very thin |

| |Contain tiny openings called , that allows carbon dioxide, water vapour, and oxygen into or out of the leaf easily. Most |

| |are found on the to minimize . |

|3. Ground Tissue |These tissues make up the of the plant, and there function depends on where it is located |

| |In the stem – provides |

| |In the roots – stores |

| |In the leaves – where occurs |

|4. Vascular Tissue |Transports up and down the plant. |

| |- movement of water and minerals from the to the leaves for photosynthesis – can only move . |

| |- transports sugar produced in photosynthesis from the to use as energy – can move both . |

Plant Organs

• There are main organs in most flowering plants:

1. The Roots

• the plant in the soil and allows the plant to grow above the soil without toppling over – provides .

• Collect from soil and transport it to them stem and store made in other parts of the plant.

2. The Leaf

• Accomplish – a chemical reaction in which carbon dioxide and water are converted into sugar and oxygen

•

• Ground tissue called is where the chemical reaction of photosynthesis actually takes place in the leaf.

3. The Stem

• Transports throughout the plant through vascular tissue (xylem and phloem)

• Supports the

4. The Flower or Fruit

• The structure of the plant – produces seeds through sexual reproduction. The is the male part of the plant, and the inside are the female part.

• When the pollen and egg unite, a fertilized egg becomes a . Some seeds are surrounded by a flesh called the , others are simply encased in a hard .

Plant Organ Systems

• Plant organ systems are much less than animal organ systems.

• There are organ systems in plants:

o The – everything the ground.

o The – everything the ground.

• Organ systems working together:

o When daylight hours , specialized cells record the changes and deliver chemical messages to the tissues to .

o Another example is when there is a lack of water or excessive heat, where chemical messages are sent to which is where the most water loss occurs.

Biology Lesson # 7 – Animals – Tissues, Organs & Systems

Name:

Animal Tissues

• There are types of tissues in animals.

|Type of Tissue |Description & Function |

|Epithelial Tissue |Cells tightly packed together to form a . |

| |Lines body cavities and surfaces, and forms that produce hormones, enzymes, and sweat. |

|Connective Tissue |Cells used to other tissues together (such as tendons, ligaments, and cartilage), forms , and fills |

|Muscle Tissue |Three types that including |

| |(moving limbs – voluntary movement) |

| |(blood vessels and organs – involuntary movement) |

| |(the heart – involuntary movement) |

|Nervous Tissue |Nerve cells which create messages, called , and transmit them throughout the body. |

| |Nerve cells can also receive messages from the body |

Animal Organ Systems

1. The Respiratory System

• The main function of this system is – and .

• Air enters the mouth or nose and travels through the (windpipe), to the lungs (big tubes called to smaller ones called ), and into smaller thin sacs called .

• Alveoli are surrounded by thin blood vessels called that allow to enter the capillaries into the blood to travel throughout the body, and allow to travel from the capillaries back to the alveoli.

• Some organisms have only lung one, but humans have that sit in a cavity in the chest area

• Lungs are coated with two sacs of connective tissue separated by a thin layer of which as the lungs move

2. The Circulatory System

• The main function of this system is to throughout the body.

• are thick-walled vessels that carry blood from the heart, with a that pushes the blood along

• carry blood to the heart, and are thinner and in pressure.

• connect the veins and arteries, and are the blood vessels – about one cell thick.

o and flow in and out of capillaries by diffusion – oxygen moves in when the cells need it, and carbon dioxide and wastes are removed from cells.

o The respiratory system and circulatory system always .

• The average heart beats about times in a lifetime

• The heart is divided into chambers: two , and two .

• The heart is a (cardiac muscle tissue) that supplies blood to all parts of the body, including the lungs and the heart itself.

• Blood contains (liquid), (carry oxygen), (protect the body from bacteria and viruses), and (help with blood clotting).

3. The Digestive System

• The main function of this system is to throughout the body.

• Food Passage:

• The mouth is covered in that secrete mucus, saliva, and enzymes

• The tongue along with the teeth starts digestion.

o The esophagus is a tube of where food travels down from the mouth

• The stomach churns food and mixes it with digestive juices (strong acids) and enzymes – where digestion begins.

• Digestive nutrients and waste move into the small and large intestines. are absorbed in the small intestine, and is absorbed in the large intestine.

• are then stored in the rectum and exit the body through the anus

4. The Excretory System

• The main function of this system is to and maintain the (salts) in the body.

• When blood flows through the , wastes (urea, carbon dioxide, water) are removed and all these wastes form a fluid called .

• Urine moves from the kidney to the urinary , where it is stored until it can be eliminated through the and out of the body.

• can also be considered a part of the excretory system, because it also excretes wastes like water and salts in sweat.

5. The Integumentary System

• The most organ system – made up mainly of and accessory structures (such as horns, antlers, hooves, quills, claws, hair, and nails, depending on the organism).

• Also made up of - skin glands include (water and body salts) to cool the body, and that produce oil that lubricates, waterproofs, and prevents skin infections.

• Skin is the in your body, which inner cells from damage and acts as a . It also Insulates and releases when necessary and excretes bodily through sweat

• Skin Layers

o - outer protective layer – thin epithelial tissue which prevents bacteria and viruses from entering, and makes vitamin D which is essential for bone development

o - inner layer – including blood vessels, pores, fat, nerves, and muscle tissue.

▪ blood vessels (get bigger) to release excess heat

▪ Pores (made in sweat glands)

▪ Fat provides

▪ Nerves allow you to feel

▪ Muscle tissue produces which prevent heat from being released.

Biology Lesson # 8 – Body Systems & Health

Name:

Homeostasis

• Body systems work together to maintain a steady state, called .

• There is an acceptable range of in which body cells, tissues, and organs can operate efficiently.

• To maintain this range, different organ systems must – they are interdependent because the action of one system contributes to the action of another system.

• Example # 1 – when you get hot, your blood vessels . You also and keep your inside temperature steady. In this example, the and systems are being used.

• Example # 2 – when you exercise, your muscles use oxygen and energy to keep you moving. Because of this, your so blood is pumped faster to your muscles, and your to provide the oxygen to the blood. In this example, the , , and systems are used.

Diagnosing Problems in Organ Systems

• Since organ systems are interdependent, it is sometimes difficult to and medical problems.

• A common physical examine includes:

o Looking at your to check your surface organs.

o Tapping of your to determine the size and density of your organs.

o Using a stethoscope to listen to the determine if they are functioning properly.

o A check to see if they are within normal ranges

o Blood is taken to test red and white (which are chemicals that carry messages to regulate cells, tissues or organs).

o Urine is taken to test for and overall health.

Medical Imaging Technologies

• Diagnostic testing provides information about the structure and function of organs, tissues, and cells through .

• In Canada, medical imaging is included as a part of our for necessary (not elective) procedures, but depending on your location in the country, there are sometimes for available appointments using these equipment, as they are very to maintain.

• There are main medical imaging technologies:

|Technology |How It Works |

|X-Ray |Most of medical imaging. |

| |An X-ray is that can easily penetrate materials like . Bone and metals absorb the energy instead, which is why they appear|

| |whiter than other structures. |

| |The image produced is called a , and can be viewed on film or computer screen and analyzed by a . |

| |It is . |

| |Can cause changes and , which is why parts of your body not being examined must be covered with a protective to limit the |

| |penetration of X-rays in those areas. |

| |A continuous beam of X-rays can show movement in the heart, stomach, and even the brain is called an . |

| |Used to check for , diagnose problems in the , and used by dentists to check for . |

|Ultrasound |Uses high-frequency , made from a device called a , to produce images of body tissues and organs |

| |The transducer is placed on the skin, and sound waves enter the body and are reflected back like an echo to the transducer by internal |

| |body structures – the makes an image of the body structures, viewed on a screen by a . |

| |Used to study , but cannot be used in areas that contain (make the image blurry) and cannot penetrate . |

| |Can also be used to study the in pregnancy. |

| |When studying the heart, it is called an (ECG). |

|Computed Tomography|Used to be called “computer assisted tomography” – a “ ” scan |

|(CT) |Involves using X-ray equipment to form a from a series of images taken at different angles of the body. |

| |Since it provides a detailed cross-sectional view of structures, it is used to diagnose , and abnormalities of the system. |

| |Used to image bone, soft tissue, and blood vessels . |

| |A head CT is used to detect |

| |Used in emergency rooms because it is . |

| |Not good for those who are , because it is a confined space. |

|Magnetic Resonance |Uses interacting with the in our body, and to produce detailed images of the body on a specialized computer |

|Imaging (MRI) |Used to look at the structure of the brain, heart, liver, soft tissues, and the inside of bones. |

| |Can diagnose and . |

| |Looks like a hollow cylinder and is open on all sides, allowing the patient to be less confined during testing – good for patients with |

Public Health Strategies

I. Vaccinations

• In vaccinations, a is injected into the body, so that your body produces to combat the weakened disease and build up immunity. After, if you are faced with the real disease, your white blood cells before it can cause any harm.

• In Ontario, we are commonly given vaccines for (the flu shot), tetanus, polio, whooping cough, rubella, measles, mumps, and bacterial meningitis. Most of these vaccines are given in , and some require “ ” shots to continue the white blood cell effectiveness in combating these diseases with age.

• The HIV Vaccine

o Right now there is no HIV vaccine, but work continues on this, because it would prevent people from being affected. In 2007, there were over people living in the world with HIV, and over people become infected every day.

o (HIV) is a virus that attacks a person’s immune system which leads to and a susceptibility to other .

o The most advanced stage of HIV is called (AIDS). It usually takes around for HIV to become AIDS, although there are some drugs currently available that slow this process for some, but not cure it.

• The HPV Vaccine

o In 2008, the link between (HPV) and was discovered, and a vaccine was developed.

o HPV is commonly spread through sexual activity, and although men cannot get cervical cancer, they can still contract HPV and to their partners.

o Currently, the vaccine has only been approved for females, and is given to girls in Grade 8 as part of Ontario government’s immunization program.

II. Promoting Public Awareness

• Public awareness programs include , , and information about for growing children and adults. Other programs include:

• Smoke-Free Environments

o Since smoking kills about people in Ontario each year, smoking has been prohibited in all workplaces and enclosed public places, as part of the .

o This program encourages people not to smoke, protects young people from second-hand smoke exposure, and helps people to quit smoking.

o Tobacco smoke contains over chemicals and one-fifth of those are toxins and carcinogens, which can cause mutations in the cells and tissues and lead .

• West Nile Virus

o The West Nile Virus is spread when a that is infected with the virus, and then that mosquito transmits the virus to other animals or humans within two weeks.

o The symptoms range from a if not treated.

o The public awareness campaign includes reminding people to minimize exposure to mosquitoes from dusk to dawn when they are the most active, to remove standing water and dense brush around their houses, the use insect repellent when outdoors, and light coloured clothing that covers the arms and legs.

III. Screening Programs

• A screening program is when a to identify those who have .

o Ontario Screening Program – recommends that women have a annually once they become sexually active to detect any abnormalities or changes in the cervix before cancer develops.

o Ontario Screening Program – provides to women between the ages of 50 and 74 years to hopefully detect signs of breast cancer early on.

o Check Program provides funding to screen for colorectal cancer, which is the leading cause of cancer death in Ontario. All adults over 50 years of age are screened using a fecal occult blood test every two years ( ).

Biotechnology

I. Organ Transplant

• Canada has a low rate of organ donation – about – not because people aren’t willing, but because we live and have a system.

• The most common organ donation from living donors is a , since we have two, and only need one to live. People on dialysis (a procedure that uses a machine to clean the blood) with kidney failure greatly benefit from this organ transplant.

• Other donations from live donors include the .

• Some organs can be donated by animals as well, including – this is called .

• In some countries, organs can be sold on the , and are removed without the consent of the donor! This is in North America.

Social & Ethical Issues:

• Risks to organ donation – surgical , risk of , , lifestyle changes

• – should people be able to sell organs if they need money?

• Animal & Human organs mixed together – ?

II. Cloning

• Cloning creates a that is an of a gene, cell, tissue, or organism.

• Cloning of has been done for many years by cutting a piece of a plant and allowing it to root in the soil to create new cloned plants. This may be done to create a consistent quality of fruit or flower, with the most .

• Reproductive cloning is the transfer of a nucleus from a donor body cell into an egg cell that has no nucleus. The egg is transferred to the womb of a mother and begins to grow. The embryo contains the genetic information that is identical to the original body cell. It is commonly used in cloning .

Social & Ethical Issues:

• Some research suggests that cloned animals have or are more susceptible to .

• In harvested plants, if one has a genetic abnormality, the entire crop would, which could lead to loss of for that year

• Would potential parents be able to eventually choose or through the process of cloning, decreasing the of the individual?

III. Reproductive Technologies

• Reproductive technologies include (AI) and (IVF).

• AI involves and placing it in the reproductive systems of a female, and can be between a specific couple, or from a sperm bank with anonymous donations. It is also commonly used on dairy and cattle farms and zoos to increase populations of endangered species.

• IVF involves and placing them together in a test tube or Petri dish so that fertilization occurs. The developing embryos are implanted in the uterus of a female.

Social & Ethical Issues:

• The does not agree with IVF, but AI is acceptable in some situations if it involves a married couple.

• Sperm banks used in AI or IVF are questionable – the donors can only be screened so well, and the issues arising from may arise when the child ages.

• In IVF, multiple embryos are implanted because the chance of success is less than 50% - sometimes this results in , and the issue of being able to afford proper care for these children comes into question.

• Also in IVF, embryos may be screened for the “best” quality – the best are implanted, and the , which is equivalent to ending a life.

• Freezing eggs and embryos is another ethical issue – some scientists argue that when frozen, the quality of egg and embryo degrades, which could lead to .

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