Download Unit A: the Science of Biology

Unit 1: CELLS: Structure and Function
Week #1
7-1
Life is Cellular
Pgs169-173
Questions
1. What three statements make up the cell theory?
All living things are composed of cells. Cells are the basic units of structure and function in living things.
New cells are produced only from existing cells.
2. What are the differences between prokaryotic cells and eukaryotic cells?
Prokaryotic cells are generally smaller and simpler than eukaryotic cells. Eukaryotic cells contain a
nucleus; prokaryotic cells do not. Eukaryotic cells generally contain dozens of structures and internal
membranes.
3. Compare the processes used to produce a TEM and an SEM.
A TEM is produced by passing electrons through an extremely thin sample. A SEM is produced by
scanning a pencil-like beam of electrons over the surface of an object.
4. What structures do all cells have?
A cell membrane and DNA
5. How did the invention of the microscope help the development of the cell theory?
The microscope was essential in that development because it allowed biologists to observe cells in living
things.
Constructing a Chart
Make a three-column chart comparing prokaryotes with eukaryotes. In the first column, list the traits
found in all cells. In the second column, list the features of prokaryotes. In the third column, list the
features of eukaryotes.
7-2
Cell Structure
Pgs 174-184
Questions
1. Describe the functions of the endoplasmic reticulum, Golgi apparatus, chloroplast and mitochondrion.
Rough ER makes membranes and secretary proteins. Smooth ER makes lipids and helps in
detoxification. The Golgi apparatus modifies, sorts, and packages proteins and other materials from the
ER for storage or secretion. Chloroplasts capture the energy of sunlight and convert it into chemical
energy. Mitochondria convert stored chemical energy into compounds that the cell can use.
2. Describe the role of the nucleus in the cell.
It is the control center of the cell.
3. What are two functions of the cytoskeleton?
It helps the cell maintain its shape and also is involved in movement.
4. How is a cell like a factory?
Answers may vary. A typical response will compare ribosomes to factory machines and the cytoskeleton
to a supporting structure. Students should also compare other organelles to various parts of a factory.
5. You examine an unknown cell under the microscope and discover that the cell contains chloroplasts.
What type of organism could you infer that the cell came from?
Students should infer that the organism would either be a plant or some other organism that carries out
photosynthesis.
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Creating Artwork
Create a work of art – such as a painting or sculpture – depicting a cross section of a plant cell or an
animal cell. Include all the different organelles described in this section that would be found in that
type of cell. Label each organelle in your artwork.
7-3
Transport
Pgs 183-189
Questions
1. Describe the functions of the cell membrane and cell wall.
The cell membrane regulates what enters and leaves the cell and also provides protection and support.
The cell wall provides support and protection for the cell.
2. What happens during diffusion?
Particles tend to move from an area where they are more concentrated to an area where they are less
concentrated.
3. Describe how water moves during osmosis.
Osmosis is the diffusion of water through a selectively permeable membrane.
4. What is the basic structure of a cell membrane?
The basic structure is a double-layered sheet called a lipid bilayer, in which proteins are embedded.
5. What is the difference between phagocytosis and pinocytosis?
In phagocytosis, extensions of cytoplasm surround a particle and package it within a food vacuole. In
pinocytosis, tiny pockets form along the cell membrane, fill with liquid and pinch off to form vacuoles
within the cell.
6. What is the main way that active transport differs from diffusion?
Active transport requires the input of energy, but diffusion does not require additional energy.
Homeostasis
What is the relationship between active transport and homeostasis? Give one example of active
transport in an organism, and explain how the organism uses energy to maintain homeostasis.
7-4
Cell Diversity
Pgs 190-193
Questions
1. In what kinds of organisms is cell specialization a characteristic?
Multicellular organisms have cell specialization.
2. List the levels of biological organization in multicellular organisms from most simple to most complex.
Individual cells, tissues, organs and organ systems
3. How are unicellular organisms similar to multicellular organisms?
Both unicellular and multicellular organisms grow, respond to the environment, transform energy and
reproduce.
4. Using what you know about the ways muscle moves, predict which organelles would be most common
in muscle cells.
Muscle cells have a large number of mitochondria, because mitochondria release energy from stored
food molecules and muscle cells need great amounts of energy to do the tasks they do.
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Using Analogies
Use an organized area in your life – such as school, sports, or extracurricular activities – to construct an
analogy to explain how the levels of organization in that chosen area can be compared with those of
living organism.
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Week#2
10-1 Limits to Growth
Pgs 241-243
Questions
1. Give two reasons why cells divide.
The larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell
has moving enough nutrients and wastes across the cell membrane.
2. How is a cell’s DNA like the books in a library?
The information that controls a cell’s function is stored in DNA, just as information needed by the
public is stored in the books of a library. A cell’s DNA, then, is a “genetic” library.
3. As a cell increases in size, which increases more rapidly, its surface area or its volume?
Its volume
4. Calculate the surface area, volume, and ratio of surface area to volume of an imaginary cubic cell
measuring 4 cm on each side.
The surface area is 96 cm2, the volume is 64 cm3, and the ratio of surface area to volume is
96/64 = 3 : 2.
Cellular Basis of Life
Select two cell organelles and describe how their functions might be impaired if the cell were to
become too large. A review of Chapter 7 may help you with this task.
10-2
Cell Division
Pgs 244-249
Questions
1. Name the main events of the cell cycle.
A cell grows, prepares for division, and divides to form two daughter cells.
2. Describe what happens during each of the four phases of mitosis.
Students should describe what happens during prophase, metaphase, anaphase and telophase, as in
Figure 10-5.
3. Describe what happens during interphase.
Students should describe what happens during the G1 phase, S phase and G2 phase.
4. What are chromosomes made of?
DNA, which carries the cell’s coded genetic information and proteins.
5. How do prokaryotic cells divide?
A prokaryotic cell first replicates its genetic information before cell division begins. In most prokaryotes,
the rest of the process of cell division is a simple matter of separating the contents of the cell into two
parts.
6. How is cytokinesis in plant cells similar to cytokinesis in animal cells? How is it different?
Cytokinesis is the division of the cytoplasm in both types of cells. The difference is that in plant cells a
cell plate forms midway between the divided nuclei.
Creative Writing
Suppose you were small enough to hitch a ride on a chromosome located in a plant cell that goes
through mitosis and cytokinesis. Describe what you would see happening during each phase of the
process.
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10-3 Regulating the Cell Cycle
Pgs 250-252
Questions
1. What chemicals regulate the cell cycle? How do they work?
Cyclins regulate the timing of the cell cycle in eukaryotic cells. Cyclin may cause a mitotic spindle to
form and trigger cell division.
2. What happens when cells do not respond to the signals that normally regulate their growth?
Such cells, called cancer cells, divide uncontrollably and form masses of cells called tumors that can
damage the surrounding tissues.
3. How do cells respond to contact with other cells?
Normal cells respond by not growing.
4. Why can cancer be considered a disease of the cell cycle?
The cell cycle is the series of events that cells go through as they grow and divide, and cancer is a
disorder in which some of the body’s cells lose the ability to control growth.
5. Write a hypothesis about what you think would happen if cyclin were injected into a cell that was in
mitosis.
A typical hypothesis might suggest that cyclin would have no effect because the cell was already in
mitosis.
Problem Solving
Imagine that you are developing a drug that will inhibit the growth of cancer cells. Use your
knowledge of the cell cycle to describe how the drug would target and prevent the multiplication of
cancer cells. Use the Internet to compare your anticancer drug with those currently in use.
40-4 Cancer
Pgs 1052-1054
Questions
1. Describe the environmental factors that affect your health.
Students should describe air and water quality, poisonous wastes in landfills and exposure to solar
radiation.
2. Name three things you can do to maintain your health.
Any three of the following: eating a healthful diet, getting enough exercise and rest, abstaining from
harmful activities, and having regular checkups.
3. List some of the causes of cancer.
Cancers are caused by defects in the genes that regulate cell growth and division. These defects may be
inherited or caused by viruses, or they may result from mutations in DNA produced by radiation or
chemicals.
4. Why are regular medical checkups and self-examinations important?
Regular medical checkups and self-examinations are important for detecting problems early so that there
is a better chance of treating them successfully.
5. Should cancer be considered an infectious disease? Explain your answer.
Most cases of cancer are not infectious. However, cancer-causing viruses can be passed from person to
person.
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Cellular Basis of Life
Recall the cell cycle from Section 10-2. In which phase do you think cells would be most vulnerable to
damage from radiation? Explain your choice. What characteristic of cancer cells might make them
especially vulnerable?
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Unit 2: The Chemistry of Life
Week #3
2-1
The Nature of Matter
Pgs 35-39
Questions
1. Describe the structure of an atom.
Atoms have a nucleus made up of protons and neutrons. Electrons are in constant motion in the space
around the nucleus.
2. Why do all isotopes of an element have the same chemical properties? In what way do isotopes of an
element differ?
They have the same number of electrons. They differ in number of neutrons.
3. What is a covalent bond? An ionic bond?
A covalent bond forms when electrons are shared between atoms. An ionic bond forms when electrons
are transferred.
4. What is a compound? How are compounds related to molecules?
A compound is a substance formed by the chemical combination of two or more elements in definite
proportions. A molecule is the smallest unit of most compounds.
5. How do van der Waals forces hold molecules together?
When the sharing of electrons is unequal, a molecule has regions that are charged. An attraction can
occur between oppositely charged regions of nearby molecules.
6. How are ionic bonds and van der Waals forces similar? How are they different?
In both cases, particles are held together by attractions between opposite charges, but the attractions are
stronger between the ions than they are between the molecules.
Writing an Article
Write an article for your school newspaper on forensic science as a career. Assume that you have
already interviewed a forensic scientist who works for a law enforcement agency. The article should be
about 500 words long. Hint: Consider the interests of your readers.
2-2
The Properties of Water
Pgs 40-43
Questions
1. Use the structure of a water molecule to explain why it is polar.
The hydrogen atoms form covalent bonds with the oxygen atom. Because of oxygen’s greater attraction
for electrons, there is an unequal distribution of electrons. The oxygen end of the bent water molecule is
negative; the hydrogen end is positive.
2. Compare acidic and basic solutions in terms of their H+ ions than OH- ion concentrations.
Per volume, there are more H+ ions than OH- in an acidic solution and more OH- ions than H+ ions in a
basic solution.
3. What is the difference between a solution and a suspension?
In a solution, all components are evenly distributed. In a suspension, undissolved particles are
suspended in the mixture and can settle out over time.
4. What does pH measure?
The pH scale measures the concentration of H+ ions in a solution.
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5. The strong acid hydrogen fluoride (HF) can be dissolved in pure water. Will the pH of the solution be
greater or less than 7?
The pH will be less than 7.0.
Creating a Concept Map
Draw a concept map on the properties of water. Include the following terms in your concept map:
hydrogen bonds, polarity, cohesion, adhesion, capillary action, and solvent.
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Week 4
2-3
Carbon Compounds
Pgs 44-48
1. Name four groups of organic compounds found in living things.
Carbohydrates, lipids, nucleic acids and proteins
Questions
2. Describe at least one function of each group of organic compounds.
A typical response might mention that living things use carbohydrates as their main source of energy, fats
can be used to store energy, and nucleic acids transmit hereditary information and proteins form tissues.
3. What properties of carbon explain carbon’s ability to form many different macromolecules?
Each carbon atom can form four covalent bonds, and carbon atoms can bond with other carbon atoms.
4. Explain why proteins are considered polymers but lipids are not.
Proteins are made up of amino acid monomers joined in long chains. Although fatty acid chains may be
mistaken for monomers, only three fatty acids can attach to a glycerol molecule.
5. Compare the structures and functions of the biomolecules lipids and starches.
Lipids are made mostly from carbon and hydrogen atoms; starch is a carbohydrate made up of carbon,
hydrogen and oxygen atoms. Both can be used to store energy.
Science as a Way of Knowing
Use what you learned about levels of organization in Section 1-3 to discuss the levels of organization in
macromolecules. Begin your discussion with the smallest structure.
2-4
Chemical Reactions/Enzymes
Pgs 49-53
Questions
1. What happens to chemical bonds during chemical reactions?
Bonds are broken in reactants and new bonds are formed in products.
2. Describe the role of energy in chemical reactions.
Some chemical reactions release energy, and other chemical reactions absorb energy. Energy changes
determine how easily a chemical reaction will occur.
3. What are enzymes, and how are they important to living things?
Enzymes are biological catalysts. Living cells use enzymes to speed up virtually every important chemical
reaction that takes place in cells.
4. Describe how enzymes work, including the role of the enzyme-substrate complex.
Substrates, the reactants of an enzyme-catalyzed reaction, attach to the enzyme at an active site and form
an enzyme-substrate complex. Once the complex is formed, the enzyme helps convert substrate into
product.
5. A change in pH can change the shape of a protein. How might a change in pH affect the function of an
enzyme such as hexokinase? Hint: Think about the analogy of the lock and key.
A change in pH could change the shape of hexokinase. This change would diminish or possibly
eliminate the ability of glucose and ATP to bind to the active site on the enzyme.
Modeling
Make a model that demonstrates how an active site and a substrate are like a lock and a key. Give a
brief talk in which you refer to your model as you explain how enzymes work.
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38-1 Food and Nutrition
Pgs 971-977
Questions
1. List the six nutrients needed by the body.
Water, carbohydrates, fats, proteins, vitamins and minerals
2. What is the importance of water in the body?
Some body tissues, such as blood, are mostly water, and water is needed for many vital body processes,
including chemical reactions, elimination of wastes, and keeping the body cool through evaporation.
3. Why is fiber an important part of your diet?
Fiber adds bulk to the material moving through the digestive system, helping it to process food more
effectively.
4. How are vitamins and minerals similar? How are they different?
Both vitamins and minerals are nutrients that are needed in small amounts for good health, but vitamins
are organic molecules, whereas minerals are inorganic.
5. Which vitamins and minerals promote healthy bones?
Vitamins C and D, calcium, phosphorus, and fluorine
Designing a Brochure
Design and create a brochure that explains how the body uses the six nutrients necessary for normal
function. Use images from magazines or from the Internet to illustrate your brochure.
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Week 5
8-1
Energy and Life
Pgs 201-203
1. What is the ultimate source of energy for plants?
The sun
Questions
2. What is ATP and what is its role in the cell?
ATP stands for adenosine triphosphate, which is one of the principal chemical compounds that living
things use to store energy and release it for cell work to be done.
3. Describe one cellular activity that uses the energy released by ATP.
A typical answer might mention active transport, movements within the cell, synthesis of proteins and
nucleic acids, or responses to chemical signals.
4. How do autotrophs obtain energy? How do heterotrophs obtain energy?
Autotrophs obtain energy by making their own food. Heterotrophs obtain energy from the foods they
consume.
5. With respect to energy, how are ATP and glucose similar? How are they different?
Similar: both store chemical energy for a cell. Different: A single molecule of glucose stores more than
90 times the chemical energy of an ATP molecule.
Interdependence in Nature
Recall that energy flows and that nutrients cycle through the biosphere. How does the process of
photosynthesis impact the flow of energy and the cycling of nutrients? You may wish to refer to
Chapter 3 to help you answer this question.
8-2
Photosynthesis
Pgs 204-207
Questions
1. What did van Helmont, Priestly and Ingenhousz discover about plants?
Van Helmont discovered that water was involved in increasing the mass of a plant. Priestly discovered
that a plant produces the substance in air required for burning. Ingenhousz discovered that light is
necessary for plants to produce oxygen.
2. Describe the process of photosynthesis, including the reactants and products.
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into oxygen and highenergy sugars.
3. Why are light and chlorophyll needed for photosynthesis?
Light provides the energy needed to produce high-energy sugars. Chlorophyll absorbs light, and the
energy of that absorbed light makes photosynthesis work.
4. Describe the relationship between chlorophyll and the color of plants.
Plants are green because green light is reflected by the chlorophyll in leaves.
5. How well would a plant grow under pure yellow light? Explain your answer.
The plant would not grow well because chlorophyll does not absorb much light in the yellow region of
visible light.
Descriptive Writing
Write a summary paragraph describing either van Helmont’s, Priestley’s, or Ingenhousz’s experiments
with plants and light. Hint: Use the first boldface key sentence on page 206 to give you an idea for the
topic sentence.
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8-3
Photosynthesis
Pgs 208-214
Questions
1. Summarize the light-dependent reactions.
The light-dependent reactions produce oxygen gas and convert ADP and NADP+ into the energy
carriers ATP and NADPH.
2. What reactions make up the Calvin cycle?
The Calvin cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy
sugars.
3. How is light energy converted into chemical energy during photosynthesis?
Light energy is converted into chemical energy by the pigments in the chloroplast.
4. What is the function of NADPH?
The main function of NADPH is to carry high-energy electrons produced by light absorption in
chlorophyll to chemical reactions elsewhere in the cell.
5. Why are the light-dependent reactions important to the Calvin cycle?
The light-dependent reactions provide the Calvin cycle with ATP and NADPH. The Calvin cycle uses
the energy in ATP and NADPH to produce high-energy sugars.
Making a Flowchart
Construct a flowchart that illustrates the steps of photosynthesis. Begin with the energy of sunlight and
end with the production of sugars. Include as much detail as possible in the numerous steps.
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Week 6
9-1
Chemical Pathways
Pgs 221-225
Questions
1. Describe the process of cellular respiration.
Cellular respiration is the process that releases energy by breaking down molecules in food in the
presence of oxygen.
2. What are the products of glycolysis?
Glycolysis produces 2 molecules of pyruvic acid, 2 molecules of ATP, and 2 molecules of NADH.
3. Name the two main types of fermentation.
Alcoholic fermentation and lactic acid fermentation.
4. What is a calorie? A Calorie?
A calorie is the amount of energy required to raise the temperature of 1 gram of water 1 degree Celsius.
A Calorie is 1000 calories.
5. How is the function of NAD+ similar to that of NADP+?
Both are electron carriers.
6. How are lactic acid fermentation and alcoholic fermentation similar? How are they different?
Similar: Both provide energy to cells in the absence of oxygen. Different: Alcoholic fermentation
produces alcohol, carbon dioxide, and NAD+, while lactic acid fermentation produces lactic acid and
NAD+.
Matter and Energy
Write the conversion of ADP to ATP as a chemical equation. What are the reactants and the product?
You may wish to refer back to Chapter 2 to review chemical equations.
9-2
Krebs Cycle/Electron Carrier
Pgs 226-232
Questions
1. What happens to pyruvic acid during the Krebs cycle?
Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions.
2. How does the electron transport chain use the high-energy electrons from the Krebs cycle?
The electron transport chain uses the high-energy electrons from the Krebs cycle to convert ADP and
ATP.
3. Why is cellular respiration considered to be much more efficient than glycolysis alone?
Cellular respiration enables the cell to produce 34 more ATP molecules per glucose molecule in addition
to the 2 ATP molecules obtained from glycolysis.
4. How many molecules of ATP are produced in the entire breakdown of glucose?
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5. Compare the energy flow in photosynthesis to the energy flow in cellular respiration.
The energy flows in photosynthesis and cellular respiration take place in opposite directions.
Photosynthesis is the process that “deposits” energy, while cellular respiration is the process that
“withdraws” energy.
6. How is the chemical energy in glucose similar to money in a savings account?
The energy in glucose is “saved” and can be “withdrawn” when the body needs it.
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Unit 3: Animal Systems
Week 7
35-1 Body Systems
Pgs 891-896
Questions
1. Sequence the levels of organization in multicellular organisms.
The levels are cells, tissues, organs and organ systems.
2. What is homeostasis?
Homeostasis is the process by which organisms keep internal conditions relatively constant despite
changes in external environments.
3. Describe the functions of each of the eleven organ systems.
Students should state the functions of each of the eleven organ systems, as described in Figure 35-2.
4. What are the four types of tissue?
The four types of tissues are epithelial, connective, nervous and muscle.
5. Look at the nervous tissue in Figure 35-3. Compare the cells of the nervous tissue to the cells of one of
the other types of tissue. Which parts of an animal would contain these types of cells?
Answers may vary. Cells of nervous tissue, as well as cells of each of the other types of tissues, would be
found in the heart and in most other organs of an animal.
Making a Venn Diagram
Draw a Venn diagram to relate the four basic levels of organization in the human body. Provide at least
three examples for each level included in your diagram.
35-2 The Nervous System
Pgs 897-900
Questions
1. Describe the functions of the nervous system.
The human nervous system controls and coordinates functions throughout the body and responds to
internal and external stimuli.
2. What happens when a neuron is stimulated by another neuron?
If the stimulus is large enough, an impulse begins that travels rapidly along the axon toward the axon
terminals, where the impulse is passed on to another cell.
3. Name and describe the three types of neurons.
Sensory neurons, motor neurons and interneurons
4. Describe the role of the myelin sheath.
The myelin sheath insulates the axon and greatly increases the speed of transmission of nerve impulses.
5. How can the level of pain you feel vary if a stimulus causes an all-or-none response?
There are two possible factors: the number of sensory neurons activated by a stimulus and the frequency
of the stimulation.
Creating a Flowchart
Create a flowchart to show the events that occur as a nerve impulse travels from one neuron to the next.
Include as much detail as you can. Use your flowchart to explain the process to a classmate.
35-3 The Nervous System
Pgs 901-905
Questions
1. Discuss the overall function of the central nervous system.
The function of the central nervous system is to relay messages and to process and analyze information.
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2. Describe the functions of the two divisions of the peripheral nervous system.
The sensory division transmits impulses from sense organs to the central nervous system. The motor
division transmits impulses from the central nervous system to muscles.
3. How is the central nervous system protected from injury?
It is protected by the skull and vertebrae, the meninges and the cerebrospinal fluid.
4. What is the role of the hypothalamus?
It recognizes and analyzes hunger, thirst, fatigue, anger and body temperature. It also controls the
coordination of the nervous and endocrine systems.
5. Is a reflex part of the central nervous system, the peripheral nervous system, or both? Explain.
Both, because it involves sensory and motor neurons of the peripheral system and is processed in the
spinal cord.
6. Would you expect the cerebrum of a bird to be more or less developed relative to its size than the
cerebrum of a human? Explain.
Less developed, because birds have less ability to think and learn than humans do.
Structure and Function
Using Section 34-1, decide which parts of the nervous system are most likely to be involved with innate,
or inborn, behaviors. Which parts are likely to be involved with learned behaviors? Explain your
reasoning.
35-4 The Nervous System
Pgs 906-909
Questions
1. Name the five types of sensory receptors and list where they are found in the body.
Pain receptors: everywhere except the brain; thermoreceptors: skin, body core, hypothalamus;
mechanoreceptors: skin, skeletal muscles, inner ears; chemoreceptors: nose, taste buds; photoreceptors:
eyes
2. Identify the functions of the cornea, pupil, lens, retina and optic nerve.
Cornea: helps to focus light; pupil: controls the amount of light that enters the eye; lens: adjusts focus
for near or far distances; retina: rod and cone photoreceptors convert light into electrical impulses; optic
nerve: carries the electrical impulses to the brain
3. What are the four basic tastes detected by the tongue?
The four basic taste receptors are receptors for salty, bitter, sweet and sour tastes.
4. Explain why you can’t “taste” food when you have a bad cold.
Because much of the sense of taste is actually due to interaction with the sense of smell.
5. If you spin around for a time, the fluid in your semicircular canals also moves. When you stop suddenly,
you feel as though you are still moving. Why do you think you might feel dizzy?
Sensory receptors lag behind the rapid changes in position.
Creative Writing
Imagine that you have to do without your sense of taste for one day. How would this influence your
food choices? Write a 3 to 4 paragraph essay describing how the absence of this sense organ would
affect your day.
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35-5 Drugs
Pgs 910-914
Questions
1. Describe the effects of stimulants, cocaine, depressants and opiates on the central nervous system.
Stimulants increase the release of neurotransmitters, cocaine causes the sudden release of dopamine,
depressants enhance the effects of certain neurotransmitters, and opiates mimic endorphins.
2. Explain the effects of alcohol on the body.
As a depressant, alcohol slows down the rate at which the central nervous system functions.
3. What is a drug?
Any substance other than food that causes a change in the body.
4. Why is drinking and driving an extremely dangerous behavior?
Because alcohol slows down reflexes, disrupts coordination and impairs judgment.
5. Which do you think is a more difficult addiction to break: one in which a person is physically dependent
on a drug, or one in which a person is psychologically dependent on a drug? Explain your answer.
Some students might say a psychological dependence is more difficult to break. Others might say a
physical dependence is more difficult to break. Students should support their conclusions with sound
reasoning.
Persuasive Writing
Research one of the drugs mentioned in this section to find out more about the short and long term
effects of the drug on the body. Then, develop an informational brochure trying to persuade someone
not to take the drug. Hint: Be sure to include specific facts.
36-1 Skeletal System
Pgs 921-925
Questions
1. List the different functions of the skeletal system.
The skeletal system supports the body, protects internal organs, allows movement, stores mineral
reserves and provides a site for blood cell formation.
2. Describe the structure of a typical bone.
A typical bone has a thick layer of compact bone covered by periosteum. Haversian canals contain the
blood vessels and nerves. At the ends of long bones, there is a layer of spongy bone beneath the
compact bone layer.
3. What is a joint? List the three types of joints.
A joint is a place where one bone attaches to another. Three types of joints are immovable, slightly
movable, and freely movable.
4. How does compact bone differ from spongy bone?
Compact bone is denser than spongy bone. Spongy bone is found in the ends of long bones and in the
middle of short, flat bones.
5. Why do you think the amount of cartilage decreases and the amount of bone increases as a person
develops?
The cartilage decreases because minerals replace cartilage during ossification.
Creative Writing
Use library or Internet resources to find out more about osteoporosis. Then, develop an advertising
campaign for the dairy industry based on the relationship between milk and healthy bone development.
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36-2 Muscular System
Pgs 926-931
Quesitons
1. List the three types of muscle tissue and explain the function of each.
Skeletal, which controls voluntary movements; smooth, which controls involuntary movements; and
cardiac, which controls contractions of the heart
2. Explain how a muscle contracts.
Myosin cross-bridges cause the thin filaments to slide over the thick filaments, shortening the muscle.
3. Describe the importance of regular exercise.
It maintains muscular and skeletal strength; increases coordination, endurance and flexibility; and
decreases body fat.
4. What is the function of the muscular system?
To control body movement, help circulate blood, and help move food through the digestive system.
5. What is the role of acetylcholine in the process of muscle contraction?
Acetylcholine is a neurotransmitter. It diffuses across nerve synapses to produce impulses in muscle cell
membranes.
6. If a muscle cell receives a second stimulus while it is contracting, will it respond to the second stimulus?
Explain
No; it must relax before it can respond to a second impulse.
Using Models
Create your own model to show how actin filaments slide over myosin filaments during a muscle
contraction. Include as much detail in your model as possible.
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Week 8
36-3
Integumentary System
Pgs 933-936 Questions
1. List the functions of the integumentary system.
Serves as a barrier against infection and injury, helps regulate body temperature, removes waste products,
protects against UV radiation, and allows sensory input
2. What organs and tissues make up the integumentary system?
Skin, hair, nails and glands
3. Compare the structures of the epidermis and dermis.
The epidermis, the outer, thinner layer, contains melanin and has a surface layer of dead cells. The
dermis, the inner, thicker layer, contains blood vessels, nerves, glands, sense organs, muscles and hair
follicles.
4. How does the skin help maintain body temperature?
Blood vessels in the dermis narrow to conserve heat and widen to increase heat loss. Evaporation of
sweat also causes heat loss.
5. In what way is the growth of hair and nails similar?
Both grow from an area of rapidly dividing cells at the base of the hair or nail.
6. Why does cutting your skin hurt, but cutting your hair or nails does not hurt?
The dermis contains nerves; hair and nails have no nerves.
Structure and Function
Compare and contrast the structure and function of the dermal tissue implants discussed in Chapter 23
with the structures in human skin. In what ways are they similar? Hint: You may wish to organize
your ideas in a Venn diagram.
37-1 Circulatory System
Pgs 943-950
1. List the structures of the circulatory system.
Heart, blood vessels and blood
Questions
2. Compare the functions of the three types of blood vessels in the circulatory system.
Arteries carry blood from the heart to the tissues; capillaries bring food and oxygen to the tissues and
absorb carbon dioxide and waste products; veins carry blood back to the heart from the rest of the body.
3. Describe the path of blood circulation through the body.
The right side of the heart pumps blood from the heart to the lungs. Oxygen-rich blood from the lungs
returns to the left side of the heart, where it is pumped to the rest of the body. The veins return oxygenpoor blood to the right side of the heart.
4. What is the role of the nervous system in heartbeat regulation?
Neurotransmitters released by the sympathetic nervous system increase heartbeat. Those released by the
parasympathetic nervous system decrease heartbeat.
5. If you were standing, would you expect the blood pressure to be higher in your arm or in your leg?
Explain your answer.
It would be higher in your arm because your arms are physically closer to your heart. Blood pressure
decreases as you move farther from the heart.
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Cause and Effect
Use library or Internet resources to research the connection between a high-fat diet and cardiovascular
disease. Write a short commentary that could be used on a television news program that explains the
connection. Hint: Prepare a cause-and-effect diagram to organize your ideas.
37-2 Blood/Lymph System
Pgs 951-955
Questions
1. List the main function of the red blood cells, white blood cells and platelets.
Red blood cells carry oxygen; white blood cells fight infection; platelets help blood to clot.
2. Describe the role of the lymphatic system.
Its role is to collect fluid lost by blood and return it to the circulatory system.
3. What types of materials are dissolved in plasma?
Gases, salts, nutrients, enzymes, hormones, waste products and plasma proteins
4. Explain how blood clots.
When platelets come in contact with the broken edges of a blood vessel, their surfaces become sticky. A
cluster of platelets develops around the wound. The platelets release clotting factors, which start
reactions that produce a blood clot.
5. Sometimes lymph nodes must be surgically removed. Although more lymph vessels eventually grow,
what result would you expect to see immediately after surgery?
Areas without lymph nodes and vessels would retain excess fluid and become swollen immediately after
surgery.
Constructing a Concept Map
Construct a concept map that shows the components of blood. Include information about the functions
of the different components. (Be sure to include the different types of white blood cells.)
37-3 Respiratory System
Pgs 956-963
Questions
1. Interpret the function of the respiratory system by stating what it does.
It brings about the exchange of oxygen and carbon dioxide between the blood, the air, and tissues.
2. Describe some of the health problems caused by smoking tobacco.
Chronic bronchitis: bronchi become swollen and clogged with mucus; emphysema: loss of elasticity in
lungs; lung cancer: deadly disease that spreads to other parts of body
3. Explain the process of gas exchange in the lungs.
Oxygen diffuses from alveoli into the blood across capillary walls, and carbon dioxide diffuses from
blood into air in the alveoli.
4. Describe how breathing is controlled.
When the level of carbon dioxide rises in the blood, the breathing center sends out nerve impulses that
cause the diaphragm to contract and bring air into the lungs.
5. As you have read, the breathing center in the brain responds to the level of carbon dioxide in the blood –
not the level of oxygen. What consequences does this have for people at high altitudes?
The level of carbon dioxide in their blood is normal, so their breathing center does not increase the rate
of breathing. As a result, they do not get enough oxygen.
19
Structure and Function
Compare what you learned in Units 8 and 9 about respiration in terrestrial arthropods, fish, and
flatworms with human respiration. Relate the method of respiration to the type of environment the
organism inhabits. What do these methods have in common? How do they differ?
38-2 Digestive System
Pgs 978-984
Questions
1. List the organs of the digestive system and give the function of each.
Mouth: begins mechanical digestion, begins chemical digestion of starch; esophagus: moves food to
stomach; stomach: continues mechanical digestion, begins chemical digestion of protein; small intestine:
completes chemical digestion of starch and protein, chemical digestion of fats; large intestine: removes
water from undigested food.
2. Explain the function of the digestive system.
To help convert foods into simple molecules that can be absorbed and used by cells.
3. How do mechanical and chemical digestion work together to break down foods?
Mechanical digestion physically breaks down food into smaller pieces, which makes it easier for enzymes
to chemically break down large food molecules into smaller molecules.
4. How does bile help in the digestion of fats?
Bile dissolves and disperses fat droplets, making it easier for enzymes to reach and further break down
fats.
5. What can you infer about the diet of an animal that has a large appendix?
The diet probably contains a lot of cellulose.
Matter and Energy
How would the rate of digestion be affected if enzymes were not released by the various organs and
glands? You may wish to refer to Chapter 2 for a review of enzyme action.
38-3 Excretory System: Kidney
Pgs 985-989
Questions
1. What are the functions of the kidneys?
Kidneys remove waste products from blood, maintain blood pH, and regulate water content and volume
of blood.
2. Describe how blood is purified.
Blood enters a nephron through the arteriole; impurities are filtered out and emptied into the collecting
duct; purified blood exits through the venule.
3. Describe the structures of a kidney.
Renal medulla: inner part of kidney; renal cortex: outer part of kidney; nephron: functional unit of
kidney; renal artery and vein: blood vessels entering and leaving kidney; glomerulus: small network of
capillaries in nephron; Bowman’s capsule: hollow, cup-shaped structure in nephron; loop of Henle:
section of nephron tubule; collecting duct: tube for transferring waste.
4. What is the role of the skin in excretion?
The skin excretes water, salts, and urea in sweat.
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5. When there is too much fluid in the blood, the heart must pump harder. Diuretics are substances that
stimulate the kidneys to remove more fluid from the body. Why do you think diuretics are often
prescribed as a treatment for high blood pressure?
Because diuretics reduce the volume of blood and, thereby, lower blood pressure.
Constructing a Flowchart
Construct a flowchart that illustrates how wastes are removed by the kidneys. Be sure to include the
terms Bowman’s capsule, loop of Henle, capillaries, collecting duct and ureter.
21
Week 9
39-1 Endocrine System Pgs 997-1002
Questions
1. Describe the function of the endocrine system in the body.
To produce hormones that affect the activities of cells throughout the body
2. Explain how the endocrine system helps maintain homeostasis.
The endocrine system, along with the autonomic nervous system, continually adjusts many body
activities, helping the body maintain relatively constant internal conditions.
3. Compare endocrine glands and exocrine glands.
Endocrine glands secrete hormones directly into the bloodstream. Exocrine glands release their
secretions through ducts.
4. What are prostaglandins and why are they called “local hormones”?
All cells produce hormonelike substances called prostaglandins, which are called “local hormones”
because they affect only nearby cells or tissues.
5. What are the advantages of having both a nervous system and an endocrine system?
The nervous system broadcasts specific messages quickly to a limited number of cells, whereas the
endocrine system broadcasts messages slowly to target cells throughout the body.
Cellular Basis of Life
Use what you learned in Chapter 7 about diffusion and how materials cross cell membranes to explain
the actions of steroid hormones and nonsteriod hormones.
39-2 Endocrine System
Pgs 1003-1008
Questions
1. Describe the role of each major endocrine gland.
Pituitary: regulates functions such as growth and actions of other glands; hypothalamus: controls the
pituitary gland; parathyroids and thyroid: metabolism and level of calcium in blood; adrenals:
metabolism, salt excretion, and response to stress; pancreas: level of blood glucose; ovaries and testes:
production of gametes and secretion of sex hormones.
2. Why is the hypothalamus an important part of both the nervous system and the endocrine system?
It monitors sensory input from the nervous system and uses it to control the endocrine system via the
pituitary gland.
3. What endocrine gland goes to work when you are surprised with a pop quiz?
The adrenal gland
4. What are the two types of diabetes mellitus?
Type I (little or no secretion of insulin) and Type II (low or normal levels of insulin but cell response to
insulin is inefficient).
5. Suppose the secretion of a certain hormone causes an increase in the concentration of substance X in the
blood. A low concentration of X causes the hormone to be released. What is the effect on the rate of
hormone secretion if an abnormal condition causes the level of X in the blood to remain very low.
The rate of hormone secretion remains high.
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Creating an Informational Brochure
Create a brochure that describes both types of diabetes. You may wish to include information on risk
factors, treatment, and preventive measures that can be taken. Use images from magazines or the
Internet to illustrate your brochure. Hint: Be sure to choose some high-interest images to make your
brochure visually appealing.
23
Week 10
39-3 Reproductive System
Pgs 1019-1015
Questions
1. Describe the functions of the male and female reproductive systems.
To produce, store and release gametes; The female reproductive system also prepares the female’s body
to nourish a developing embryo.
2. What happens during each of the four phases of the menstrual cycle?
Follicular phase: egg develops; ovulation: egg is released; luteal phase: egg travels through Fallopian
tube, where it may be fertilized, to the uterus; menstruation: lining of uterus, blood and egg are
discharged through vagina.
3. What is puberty?
Puberty is a period of rapid growth and sexual maturation.
4. Name two STD’s caused by bacteria and two caused by viruses.
Bacterial STDs include Chlamydia, syphilis, and gonorrhea. Viral STDs include hepatitis B, genital
herpes, genital warts and AIDS.
5. Which hormone is at its peak during ovulation? (Hint: You may wish to refer to Figure 39-16.)
Luteinizing hormone, or LH
Information and Heredity
How many chromosomes are there in a human egg cell or in a sperm cell? How many are there in a
fertilized egg? You may wish to refer back to Section 14-1.
39-4 Fertilization/Development
Pgs 1016-1024
Questions
1. Describe the process of fertilization.
Sperm attaches to a binding site and releases enzymes that attack the egg’s protective layer; egg and
sperm nuclei merge.
2. Describe the role of the placenta.
The placenta is the embryo’s organ of respiration, nourishment and excretion.
3. Describe the three stages of early development.
Implantation: blastocyst attaches itself to the wall of the uterus; gastrulation: three cell layers form;
neurulation: the nervous system develops.
4. What are the three germ layers that result from gastrulation?
Ectoderm, mesoderm and endoderm
5. What is oxytocin, and what is its role in childbirth?
Oxytocin is a hormone that stimulates labor.
6. Why do you think doctors recommend that women avoid most medications and alcohol during
pregnancy?
Because these substances may cross the placenta and harm the embryo or fetus
Creating a Timeline
Starting with your birth date, create a timeline of physical and social developmental milestones. As
resources, you can use interviews, photographs and memories.
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40-2 Immune System
Pgs 1036-1042
Questions
1. Describe the body’s nonspecific defenses against pathogens.
Unbroken skin is a barrier to pathogens. If pathogens penetrate the skin, they cause an inflammatory
response. Pathogens that enter through the mouth or nose are trapped in mucus, or attacked by
lysozyme, digestive enzymes, and stomach acid. Viruses trigger the production of interferons.
2. Describe the function of the immune system.
To protect the body against pathogens.
3. How do interferons protect the body against viruses?
Interferons inhibit the progress
4. How are antigens related to antibodies?
An antigen is a substance on the surface of a pathogen that triggers an immune response. Antibodies are
molecules that are custom-made to bind to specific antigens.
5. How are active and passive immunity similar? How are they different?
They both provide antibodies against a specific pathogen. Active immunity is often permanent; passive
immunity is temporary.
Science, Technology and Society
Getting vaccinated is much safer than getting the disease that the vaccine prevents. However, like any
drug, vaccines are capable of causing serious problems. Interview five people about their thoughts on
vaccinations. As a class, arrange a debate that addresses both the benefits and risks of vaccinations.
40-3 Immune System
Pgs 1043-1047
Questions
1. What happens in an autoimmune disease?
In an autoimmune disease, the immune system attacks the body’s own cells.
2. Describe the various ways HIV is transmitted from person to person.
Answers should include the four bulleted items on page 1046.
3. What are the two main types of immune system disorders?
Autoimmune diseases, and immunodeficiency diseases.
4. Why is it difficult for a person with HIV to fight off infections?
HIV kills off most of the helper T cells, which greatly reduces the immune system’s response to
infection.
5. In treating asthma, the first thing many physicians do is ask patients to list times and places they have
experienced asthmatic reactions. Why do you think doctors do this?
Doctors ask asthmatic patients where and when their asthmatic reactions occur in order to identify the
antigens that trigger the asthma attacks.
Structure and Function
Compare the process of HIV replication with that of other viruses. You may wish to review Figure 40-14
as well as Chapter 19.
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Week 11
11-1 Gregor Mendel
Pgs 263-266 Questions
1. What are dominant and recessive alleles?
Dominant: form of an allele whose trait always shows up if it is present; recessive: form of an allele
whose trait shows up only when the dominant allele is not present.
2. What is segregation? What happens to alleles during segregation?
Separation of paired alleles; the alleles are separated during the formation of gametes, with the result that
each gamete carries only a single allele from the original pair.
3. What did Mendel conclude determines biological inheritance?
Factors that are passed from one generation to the next
4. Describe how Mendel cross-pollinated pea plants.
Mendel cut away the male parts of one flower, then dusted it with pollen from another flower.
5. Why did only about one fourth of Mendel’s F2 plants exhibit the recessive trait?
Only one-fourth of the possible gamete combinations did not have a dominant allele.
6. Why were true-breeding pea plants important for Mendel’s experiments?
True-breeding pea plants have two identical alleles for a gene, so in a genetic cross each parent
contributed only one form of a gene, making inheritance patterns more detectable.
Using Diagrams
Use a diagram to explain Mendel’s principles of dominance and segregation. Your diagram should
show how the alleles segregate during gamete formation.
11-2 Probability
Pgs 267-269
Questions
1. How are the principles of probability used to predict the outcomes of genetic crosses?
The way in which the alleles segregate is random, and probability allows the calculation of the likelihood
that a particular allele combination will occur in offspring.
2. How are Punnett squares used?
To predict and compare the genetic variations that will result from a cross
3. What is probability?
The likelihood that a particular event will occur
4. Define the terms genotype and phenotype.
Genotype: actual alleles present for a trait, or genetic makeup; phenotype: visible expression of the
alleles, or physical characteristics.
5. An F1 plant that is homozygous for shortness is crossed with a heterozygous F1 plant. What is the
probability that a seed from the cross will produce a tall plant? Use a Punnett square to explain your
answer and to compare the probable genetic variations in the F2 plants.
50 percent; Punnett square:
T
t
t
Tt
tt
t
Tt
tt
26
Drawing Punnett Squares
Imagine that you came upon a tall pea plant similar to those Mendel used in his experiments. How
could you determine the plant’s genotype with respect to height? Draw two Punnett squares to show
your answer.
Mendelian Genetics
1. Explain what independent assortment means.
During gamete formation, pairs of alleles for different traits segregate, or separate, independently of each
other.
2. Describe two inheritance patterns besides simple dominance.
Answers include descriptions for any two: incomplete dominance, codominance, multiple alleles, or
polygenic traits.
3. What is the difference between incomplete dominance and codominance?
In incomplete dominance, two alleles combine their effects to produce a single in-between phenotype,
such as pink flowers from red and white parents. In codominance, each allele is expressed separately, as
when erminette chickens have both black and white feathers.
4. Why are fruit flies an ideal organism for genetic research?
They are small, easy to keep in the laboratory, and produce large numbers of offspring in a short period
of time.
5. A geneticist studying coat color in animals crosses a male rabbit having the genotype CC with a female
having genotype Ccch. The geneticist then crosses a ccch male with a Ccc female. In which of the two
crosses are the offspring more likely to show greater genetic variation? Use Punnett squares to explain
your answer.
The offspring in the second cross will show greater variation because 100 percent of the offspring from
the first cross (CC x Ccch) will be full color.
Problem Solving
Construct a genetics problem to be given as an assignment to a classmate. The problem must test
incomplete dominance, codominance, multiple alleles, or polygenic traits. Your problem must have an
answer key that includes all of your work.
27
Week 12
Meiosis
Pgs 275-278
Questions
1. Describe the main results of meiosis.
Four haploid cells genetically different from one another and from the original cell
2. What are the principal differences between mitosis and meiosis?
Mitosis produces two genetically identical diploid cells; meiosis produces four genetically different
haploid cells.
3. What do the terms diploid and haploid mean?
Diploid: two sets of chromosomes; haploid: one set of chromosomes
4. What is crossing-over?
Homologous chromosomes pair up and form tetrads, which may exchange portions of their chromatids,
resulting in the exchange of alleles between the homologous chromosomes.
5. In human cells, 2N = 46. How many chromosomes would you expect to find in a sperm cell? In an egg
cell? In a white blood cell? Explain.
Both sperm and egg cells have 23 chromosomes because they are gametes, which are haploid cells. A
white blood cell has 46 chromosomes because it is a diploid body cell.
Information and Heredity
In asexual reproduction, mitosis occurs, but not meiosis. Which type of reproduction – sexual or
asexual – results in offspring with greater genetic variation? Explain your answer.
11-5 Linkage
Pgs 279-280
Questions
1. How does the principle of independent assortment apply to chromosomes?
It is the chromosomes that assort independently, not individual genes.
2. What are gene maps, and how are they produced?
A gene map shows the relative locations of genes on a chromosome. The frequency of crossing-over
between genes is used to produce a map of distances between genes.
3. How does crossing-over make gene mapping possible?
The farther apart two genes are, the more likely they are to be separated during a crossover in meiosis.
Therefore, the frequency of crossing-over is equal to the distance between two genes.
4. If two genes are on the same chromosome but usually assort independently, what does that tell you
about how close together they are?
The two genes are located very far apart from each other.
Cause-Effect Paragraph
In your own words, explain why the alleles for reddish-orange eyes and miniature wings in Drosophila
are usually inherited together. Include the idea of gene linkage. Hint: To organize your ideas, draw a
cause-effect diagram that shows what happens to the two alleles during meiosis.
12-1 DNA
Pgs 287-294
Questions
1. List the conclusions Griffith, Avery, Hershey and Chase drew from their experiments.
Griffith and Avery: genes were probably made of DNA; Hershey and Chase: genetic material of
bacteriophage was DNA, not protein.
28
2. Describe Watson and Crick’s model of the DNA molecule.
DNA is a double helix in which two strands are wound around each other.
3. What are the four kinds of bases found in DNA?
Adenine, thymine, guanine, cytosine
4. Did Watson and Crick’s model account for the equal amounts of thymine and adenine in DNA?
Explain.
Yes; hydrogen bonds can form only between certain base pairs – adenine with thymine and guanine with
cytosine.
5. Why did Hershey and Chase grow viruses in cultures that contained both radioactive phosphorus and
radioactive sulfur? What might have happened if they had used only one radioactive substance?
So that both the viral DNA and viral proteins would be marked; either they would not have been able to
trace the location of the unmarked molecule in the bacterial cell, or the results would not have been
conclusive.
Science as a Way of Knowing
Using the experiments of Griffith, Avery, or Hershey and Chase as an example, develop a flowchart that
shows how the scientist or scientists used scientific processes. Be sure to identify each process. Hint:
You may wish to review Chapter 1 which describes scientific methods.
12-2 Replication
Pgs 295-299
Questions
1. Explain how DNA is replicated.
The DNA molecule separates into two strands, which serve as templates against which the new strands
are made, following the rules of base pairing.
2. Where and in what form is eukaryotic DNA found?
In the cell nucleus as chromosomes
3. How are the long DNA molecules found in eukaryotes packed into short chromosomes?
DNA is tightly wound around histones, forming nucleosomes. Nucleosomes are tightly coiled and
supercoiled to form chromosomes.
4. How are histones related to nucleosomes?
Nucleosomes are composed of DNA wound around histones.
5. What is the role of DNA polymerase in DNA replication?
Polymerizes individual nucleotides to produce DNA
6. How is the structure of chromosomes in eukaryotes different from the structure of chromosomes in
prokaryotes?
Prokaryotes: single, circular DNA molecule; eukaryotes: many chromosomes composed of tightly coiled
DNA and proteins called histones
Creating a Venn Diagram
Make a Venn diagram that compares the process of DNA replication in prokaryotes and eukaryotes.
Compare the location, steps and end products of the process in each kind of cell. (For more on Venn
diagrams, see Appendix A.)
29
12-3 RNA/Protein Synthesis
Pgs 300-306
1. List the three main types of RNA.
Messenger RNA, transfer RNA, ribosomal RNA
Questions
2. What happens during transcription?
RNA polymerase binds to DNA, separates the strands, and then uses one strand as a template to
assemble RNA.
3. What happens during translation?
The cell uses information from messenger RNA to produce proteins.
4. Describe the three main differences between RNA and DNA.
The sugar in RNA is ribose instead of deoxyribose; RNA is generally single-stranded; RNA contains
uracil in place of thymine.
5. Using the genetic code, identify the amino acids that have the following messenger RNA strand codes:
UGGCAGUGC
Tryptophan-glutamine-cysteine
Creative Writing
An RNA molecule is looking for a job in a protein synthesis factory, and it asks you to write its resume.
This RNA molecule is not yet specialized and could, with some structural changes, function as either
mRNA, tRNA or rRNA. The resume you create should reflect the qualifications needed for each type
of RNA.
30
Week 13
12-4 Mutations
1. What is a mutation?
A change in genetic material
Pgs 307-308
Questions
2. What is the significance of mutations to living things?
Mutations can be harmful by producing defective proteins that disrupt normal biological activities.
Mutations are also the source of genetic variability and can be beneficial.
3. What are two kinds of frameshift mutations?
Two kinds of frameshift mutations are insertions and deletions.
4. What are four types of chromosomal mutations?
Four kinds of chromosomal mutations are deletions, duplications, inversions and translocations.
5. The effects of a mutation are not always visible. How might a biologist determine whether a mutation
has occurred, and if so, what type of mutation it is?
A researcher could compare the DNA sequence of normal DNA to that of the mutated DNA. The base
sequence should reveal the type of mutation.
Compare/Contrast Paragraph
Write a paragraph comparing and contrasting gene mutations and chromosomal mutations. Hint: To
organize your ideas, use a compare/contrast table. The column heads might be Definition, Types and
Effects.
13-1 Genetic Engineering
Pgs 319-321
Questions
1. Give one example of selective breeding.
Nearly all domestic animals, including horses, cats and farm animals, and most crop plants have been
produced by selective breeding.
2. Relate genetic variation and mutations to each other.
Mutations are the ultimate source of genetic variation.
3. How might a breeder induce mutations?
By using radiation and chemicals.
4. What is polyploidy?
The condition of having many sets of chromosomes
5. You are a geneticist trying to develop a sunflower with red flowers and a short stem. As you compare the
sunflowers you have, what genetic variations would you look for? What kinds of plants would you select
for crossing?
Plants with shorter stems and plants with more red pigment in their flowers.
Science, Technology, and Society
Write a paragraph in which you suggest ways that plants could be genetically altered to improve the
world’s food supply. Hint: The first sentence in your paragraph should express the paragraph’s main
idea.
31
13-2 Genetic Engineering
Pgs 322-329
Questions
1. What is transformation?
A process in which a cell incorporates DNA from outside the cell into its own DNA.
2. How can you tell if a transformation experiment has been successful?
If transformation is successful, the DNA will be integrated into one of the cell’s chromosomes.
3. How are genetic markers related to transformation?
A genetic marker makes it possible to distinguish a cell that has been transformed from those that have
not.
4. What are two features that make plasmids useful for transforming cells?
They have DNA sequences that promote plasmid replication, and they have genetic markers.
5. Compare the transformation of a bacterium cell with the transformation of a plant cell.
Recombinant plasmids are simply taken up by bacterial cells. Plant cells do not naturally take up DNA.
Recombinant plasmids are either directly injected into cells or carried into the cell by an infecting
bacterium.
Writing a Plan for an Experiment
Imagine that you are a genetic engineer. Determine what your next experiment will be. Then, write up
the steps you will follow and what your intended result will be.
13-4 Applied Genetics
Pgs 331-333
Questions
1. List one practical application for each of the following: transgenic bacteria, transgenic animals,
transgenic plants.
Sample answers: transgenic bacteria – to produce human proteins for medical use, produce materials for
plastics; animals – study genes, improve food supply, provide human proteins; plants – improve food
supply, produce human antibodies, produce plastics
2. What is a transgenic organism?
An organism that contains genes from another species.
3. What basic steps were followed to produce Dolly?
The nucleus of an egg cell is removed and replaced with a nucleus taken from another adult. This egg is
then placed in the reproductive system of a foster mother, where it develops normally.
4. List reasons you would or would not be concerned about eating genetically modified food.
Some may be concerned because the foods might harm humans, for example, by causing allergies.
Others will not be concerned because they think the genetic modifications will not affect humans
adversely.
Conducting a Survey
Survey at least ten people about their viewpoints on cloning animals. To help the people you survey
understand the topic, prepare an illustrated explanation of the process of cloning.
14-1 Human Heredity
Pgs 341-348
Questions
1. What are sex chromosomes? What determines whether a person is male or female?
X and Y chromosomes; Females have two X chromosomes; males have one X and one Y chromosome.
32
2. Using an example, explain how a small change in a person’s DNA can cause a genetic disorder.
In cystic fibrosis, for example, the deletion of three DNA bases alters the structure of a protein and
prevents its normal function. This damages tissues throughout the body.
3. How does studying genetic disorders such as PKU help biologists understand normal alleles?
A specific genetic disorder produced by an abnormal or nonfunctioning allele gives researchers clues
about the normal functionings of the gene, as when PKU was shown to result from a missing enzyme.
4. If a woman with type O blood and a man with type AB blood have children, what are the children’s
possible genotypes?
IAi and IBi
Drawing a Pedigree
Choose a family and a trait, such as facial dimples, that you can trace through three generations. Find
out who in the family has had the trait and who has not. Then, draw a pedigree to represent the family
history of the trait.
14-2 Genetic Disorders
Pgs 349-353
Questions
1. Why are sex-linked disorders more common in males than in females?
Males have just one X chromosome. Thus, all X-linked alleles are expressed in males, even if they are
recessive.
2. How does nondisjunction cause chromosome number disorders?
Chromosomes fail to separate, causing gametes to have abnormal numbers of chromosomes.
3. List at least two examples of human sex-linked disorders.
Answers include colorblindness, hemophilia, and Duchenne muscular dystrophy.
4. Describe two sex chromosome disorders.
A female with Turner’s syndrome has only one X chromosome and is sterile. A male with Kinefelter’s
syndrome has one or more extra X chromosomes and is usually sterile.
5. Distinguish between sex-linked disorders and sex chromosome disorders.
Sex-linked disorders are caused by alleles of genes usually carried on the X chromosome. Sex
chromosome disorders are caused by nondisjunction, or sex chromosomes failing to separate correctly
during meiosis.
Explaining a Process
Write a paragraph explaining the process of nondisjunction. Hint: To organize your writing, refer to
Figure 14-15 and use this diagram to create a flowchart that shows the steps in the process.
14-3 Human Molecular Genetics
Pgs 355-360
1. What is the Human Genome Project?
An ongoing effort to analyze the human DNA sequence
Questions
2. Describe how gene therapy works.
An absent or faulty gene is replaced by a normal, working gene.
3. Name two common uses for DNA testing.
To detect alleles for a genetic disorder and to identify individuals.
33
4. Describe how molecular biologists identify genes in sequences of DNA.
By looking for promoters, which are binding sites for RNA polymerase; an open reading frame and
introns as well as exons
5. Evaluate the potential impact of the Human Genome Project on both scientific thought and society.
How has it improved our understanding of human genetics? How might it be used to benefit
humankind? What potential ethical problems might it create?
Possible answer: Learn causes of genetic disorders and how the inheritance and expression of human
traits is controlled. Helpful in curing diseases, but could cause discrimination and the manipulation of
human traits for profit.
Science, Technology and Society
Biologists may one day be able to use genetic engineering to alter a child’s inherited traits. Under what
circumstances, if at all, should this ability be used? When should it not be used? Write a persuasive
paragraph expressing your opinion. Hint: Use specific examples of traits to support your ideas.
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Week 14
16-1 Genes and Variation
Pgs 393-396 Questions
1. In genetic terms, what indicates that evolution is occurring in a population?
Evolution is occurring when there is a change in the relative frequency of alleles in a population.
2. What two processes can lead to inherited variation in populations?
Mutations and the genetic shuffling that results from sexual reproduction.
3. How does the range of phenotypes differ between single-gene traits and polygenic traits?
Single-gene traits have only two distinct phenotypes. Polygenic traits can have many possible
phenotypes.
4. What is a gene pool? How are allele frequencies related to gene pools?
A gene pool is the combined genetic information of all members of a particular population. Allele
frequencies are the number of times certain alleles occur in a particular gene pool compared with other
alleles.
5. Evaluate the significance of mutations to the process of biological evolution. Hint: How does mutation
affect genetic variation?
Mutations increase genetic variation, which is needed for natural selection to bring about evolutionary
change.
Information and Heredity
How does the process known as independent assortment relate to the genetic variation that results
from sexual reproduction? Hint: Refer to Chapter 11.
16-2 Genetic Change
Pgs 397-402
Questions
1. Describe how natural selection can affect traits controlled by single genes.
It can lead to changes in allele frequencies and the evolution of traits.
2. Describe three patterns of natural selection on polygenic traits. Which one leads to two distinct
phenotypes?
Directional selection favors one extreme; stabilizing selection favors the middle of the range; disruptive
selection favors both extremes and leads to two phenotypes.
3. How does genetic drift lead to a change in a population’s gene pool?
Genetic drift causes random changes in allele frequencies in small populations.
4. What is the Hardy-Weinberg principle?
Allele frequencies in a population remain constant unless one or more factors cause the frequencies to
change.
5. How are directional selection and disruptive selection similar? How are they different?
Both are types of selection on polygenic traits in which the curve shifts away from the middle. In
directional selection, the curve shifts toward one end, and in disruptive selection, toward both ends.
Using Models
Demonstrate natural selection on polygenic traits by cutting a sheet of paper into squares of five
different sizes to represent sizes in a population. Use the squares to model directional, stabilizing and
disruptive selection. Then, think of an alternative way to model one type of selection. Decide which
model works best, and give your reasons.
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