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INSTANT DOWNLOAD COMPLETE TEST BANK WITH ANSWERS
 
 
Biology A Guide To The Natural World 5th Edition By David Krogh – Test Bank
 
Sample  Questions

 

Exam

 

Name___________________________________

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

1) What is the difference between a tissue and an organ system? 1)
  1. An organ system includes tissues.
  2. Tissues are not composed of cells, but organ systems are composed of cells.
  3. A tissue cannot exist unless it is part of an organ system, but an organ system can exist independently of tissues.
  4. Tissues are composed of organ systems.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

2) Which of the following is an example of how living things assimilate energy? 2)
A) producing a new generation of offspring
B) solving a mathematics problem
C) blinking at a bright light
D) eating a meal
Answer: D
Explanation: A)
B)
C)
D)
3) Because scientists are in the business of investigating nature, scientists function as: 3)
A) society’s eyes and ears on the natural world.
B) protectors of the natural world.
C) political advisors.
D) authorities on the natural world.
Answer: A
Explanation: A)
B)
C)
D)
4) Evolution allows us to explain: 4)
  1. both the diversity of life and how all living things are related.
  2. only the diversity of life.
  3. only the origin of life.
  4. only the unity of life.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

1

 

5) The liver releases glucose into the bloodstream if you don’t eat for a long time. This represents an 5)

example of a characteristic possessed by all living things. Which is it?

  1. A) possessing an inherited information base
  2. B) maintaining a relatively constant internal environment
  3. C) being able to reproduce
  4. D) being composed of cells

 

Answer: B

Explanation:      A)

B)

C)

D)

 

6) The questions that can be answered by science are: 6)
  1. limited by what can be investigated using the scientific method.
  2. limited only by imagination.
  3. without limit.
  4. limited by what is found in the living world.
  5. limited by religious doctrine.

 

Answer: A

Explanation:      A)

B)

C)

D)

E)

 

7) Biology developed as a science later than physics because: 7)
  1. biologists had to invent rules of the living world before they could describe the forms.
  2. the living world is tremendously diverse compared to the non-living world.
  3. it is more difficult to come up with ways of describing nature.
  4. biology is less complex than physics.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

8) Living things inherit information from their parents encoded in: 8)
  1. A) atoms.
  2. B) fats.
  3. C) proteins.
  4. D) DNA.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

2

 

9) Which of the following is the most complex level of organization? 9)
A) a rainforest
B) the circulatory system
C) a heart
D) a water molecule
Answer: A
Explanation:   A)
B)
C)
D)
10) When Pasteur tested the hypothesis of spontaneous generation, he compared the ability of a 10)
sterilized growth medium (meat broth) to produce a population of bacteria in two different types of

flasks. One had a simple neck open to the outside, and the other had a “goose neck” bend that also was open to the environment. Pasteur expected that bacteria would appear in the flask with the standard neck. In this experiment, the standard neck flask served as a/an:

 

Answer: E

Explanation:      A)

B)

C)

D)

E)

 

11) A good hypothesis must: 11)
A) be theoretical.
B) be falsifiable.
C) be true.
D) be false.
E) lead to a question.
Answer: B
Explanation: A)
B)
C)
D)
E)
12) Which of the following is at the root cause for all cancers? 12)
A) the normal cell division process
B) antibiotic resistance
C) obesity
D) a breakdown of the cell division process
Answer: D
Explanation: A)
B)
C)
D)

 

 

 

3

 

13) Choose the answer that best describes the sequence of the scientific method. 13)
  1. A) observation, hypothesis, experiment, conclusion
  2. B) experiment, observation, hypothesis, conclusion
  3. C) hypothesis, experiment, observation, conclusion
  4. D) observation, hypothesis, experiment, absolute fact
  5. E) guess, hypothesis, experiment, conclusion

 

Answer: A

Explanation:      A)

B)

C)

D)

E)

 

14) Organelles are: 14)
  1. a group of cells that serve a common function.
  2. like tiny organs within cells.

 

Answer: B

Explanation:      A)

B)

C)

D)

E)

 

15) Which one of the following is true about scientific knowledge? 15)
  1. Scientific knowledge is acquired though teachings passed on by great scientists.
  2. Scientific knowledge is derived from the strongest arguments made by the brightest scientists.
  3. Scientific knowledge is derived from careful thinking about the way things must work based on application of a few fundamental principles.
  4. Scientific knowledge is not absolute, because the possibility is always held open that new experiments may one day prove it wrong.

 

  1. When based on many experiments, scientific knowledge is absolutely true.

 

Answer: D

Explanation:      A)

B)

C)

D)

E)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

16) Which of the following is the correct order of complexity, going from least to most complex? 16)
A) organ, tissue, cell, organelle, atom, molecule
B) molecule, atom, organ, tissue, cell, organelle
C) atom, molecule, organelle, cell, tissue, organ
D) organ, tissue, cell, organelle, molecule, atom
E) atom, molecule, organelle, cell, organ, tissue
Answer: C
Explanation: A)
B)
C)
D)
E)
17) A scientific explanation that is tentative and testable is termed a/an: 17)
A) hypothesis.
B) theory.
C) observation.
D) control.
E) fact.
Answer: A
Explanation: A)
B)
C)
D)
E)
18) Which of the following is true? 18)
  1. A scientific theory explains what we know to this date about a natural event.
  2. A scientific theory is a hunch about a natural event.
  3. A scientific fact and a scientific theory carry the same weight in the scientific community.
  4. A scientific theory is the final answer to a question about a natural event.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

19) The difference between a theory and a hypothesis is that a: 19)
  1. theory must be supported by evidence.
  2. theory must be proven beyond a shadow of a doubt.
  3. hypothesis must be supported by evidence.
  4. hypothesis must be proven beyond a shadow of a doubt.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

5

 

20) A tree in your backyard is home to robins, squirrels, beetles, and lichens. Together all these 20)
organisms compose a/an:
A) biosphere.
B) niche.
C) community.
D) population.
E) organism.
Answer: C
Explanation:   A)
B)
C)
D)
E)
21) If you flip the light switch in your living room and nothing happens, what might be a good 21)
hypothesis to explain the absence of light?
  1. The circuit breaker for the living room might be the “off” position.
  2. Electricity sometimes flows backward in a wire, preventing the light from shining.
  3. You might have made too many telephone calls this month, thereby reducing the amount of electricity in your lines.
  4. The air conditioner is also running upstairs, and it might be using all of the electricity available in your house at the moment.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

22) The role of a control in an experiment is to: 22)
  1. provide a basis of comparison to an experimental group.
  2. prove a hypothesis is correct.
  3. prove that a hypothesis is correct and ensure repeatability.
  4. ensure the experiment can be repeated.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

23) A scientific finding is believed to be true until new evidence arises. This view is referred to as: 23)
  1. A) a theory.
  2. B) provisional assent.
  3. C) a supernatural explanation.
  4. D) immutable laws.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

6

 

24) Imagine you’re a biology instructor lecturing to a group of students interested in ecology, the 24)

branch of biology that studies interactions between organisms and their environments. The students complain bitterly that they’re not interested in atoms and molecules because these are irrelevant to their interests. As a responsible instructor aiming to provide a complete and meaningful education, you would state:

  1. “You need to study atoms and molecules because the organization of life is hierarchical; this implies that, to understand the complex (ecology), you first need to understand the simpler underlying levels.”

 

  1. “You need to study atoms and molecules because it’s in the book.”

 

  1. “You need to study atoms and molecules because life exists at the level of the atom.”
  2. “You need to study atoms and molecules because they’re important for many things.”
  3. “You need to study atoms and molecules because all biologists, regardless of their specific interests, should know about them.”

 

Answer: A

Explanation:      A)

B)

C)

D)

E)

 

25) Which scientist disproved the theory of spontaneous generation? 25)
A) Watson
B) Crick
C) Einstein
D) Pauling
E) Pasteur
Answer: E
Explanation: A)
B)
C)
D)
E)
26) We use the scientific method every day. Imagine your car doesn’t start one morning before school. 26)
Which of these is a reasonable hypothesis regarding the problem?
A) Add a quart of oil.
B) Check to see whether your lights were left on all night.
C) I’m out of gas.
D) I’m going to be late.
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

7

 

27) Which of the following is a theory? 27)
  1. A boy finds a chipped rock he believes is an arrowhead.
  2. Many people claim that the Earth is only 6,000 years old.
  3. There is molecular and biochemical evidence that all organisms are related.
  4. Many people believe echinacea cures their colds.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

28) Science presents society with ________, about which society then makes decisions. 28)
A) values
B) options
C) theories
D) worst-case scenarios
Answer: B
Explanation: A)
B)
C)
D)
29) What invention by Bell Labs in 1947 brought about modern electronics? 29)
A) the invention of the transistor
B) the invention of the computer
C) the invention of software
D) the invention of the CD
Answer: A
Explanation: A)
B)
C)
D)
30) Tissues are grouped together in functional units called: 30)
A) organisms.
B) organs.
C) cells.
D) organelles.
Answer: B
Explanation: A)
B)

C)

D)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

31) All of the kinds of living things in a given area are called a ________. 31)

 

Answer: community

Explanation:

 

 

 

 

 

 

8

 

32) The scientist who demonstrated that the Earth moves around the sun was ________. 32)
Answer: Copernicus
Explanation:
33) In terms of the hierarchical organization of life, a bacterium is at the ________ level of 33)
organization, and a human is at the ________ level of organization.
Answer: cell; organism
Explanation:
34) A unifying principle of biology states that there is a gradual modification of populations of 34)
living things over time that sometimes results in new species. This principle is called
________.
Answer: evolution
Explanation:
35) A set of disciplines that focuses on varying aspects of the living world falls under the 35)
category of ________.

 

Answer: life sciences

Explanation:

 

TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.

 

36) Observation of a natural event by more than one human or scientific instrument is the basis of the 36)
scientific method.
Answer: True False
Explanation:
37) A theory must be supported by evidence. 37)
Answer: True False
Explanation:
38) It doesn’t matter whether a hypothesis is correct when it is first stated. 38)
Answer: True False
Explanation:
39) The experiments of Louis Pasteur to disprove spontaneous generation illustrate the process of the 39)
scientific method.
Answer: True False
Explanation:
40) A hypothesis must be supported by evidence. 40)
Answer: True False
Explanation:
41) Most U.S.-grown corn is genetically modified. 41)
Answer: True False

Explanation:

 

 

 

 

 

 

 

9

 

42) Goats can be cloned to provide us with human medicines. 42)
Answer:True False
Explanation:

 

MATCHING. Choose the item in column 2 that best matches each item in column 1.

 

 

Match column 1 with the items in column 2.

  • Members of the same species living in the same area

 

Answer: D

 

  • The first level of organization that we can say is alive

 

Answer: A

 

  • Communities interacting with non-living elements Answer: C

 

  • The building blocks of organelles Answer: E

 

  • All of the ecosystems of the Earth Answer: B

 

 

A) cell 43)
B) biosphere
C) ecosystem 44)
D) population
E) molecule 45)

 

 

 

46)

 

 

47)

 

 

ESSAY. Write your answer in the space provided or on a separate sheet of paper.

 

  • Discuss why it is important that the public be knowledgeable about science.

 

Answer: After reading the chapter, students should be familiar with the reasons why it is important for the public to understand science and how lack of science education can harm society. Being scientifically literate enables people to better understand how the world around them works. Science allows people to understand the potential influence of new discoveries and technologies on their lives. A scientifically literate public affects policy decisions by the government regarding a whole host of issues, such as environmental protection, food and drug regulation, and research funding.

 

  • The European corn borer is an insect whose larvae eat corn crops, thus reducing the yield of the crops. Scientists have genetically modified corn in the hopes of making it more resistant to infestation by the European corn borer. Design an experiment to test whether the genetically modified variety is more resistant to infestation than an unmodified variety. State your hypothesis, and identify your experimental group and your control.

 

Answer: A hypothesis could be that the genetically modified corn is more resistant to infestation than unmodified corn. The experimental group would be a field of genetically modified corn that is infested with the corn borer. The control group would be a field of unmodified corn infested with the same number of corn borers. The amount of corn produced by the experimental group would be compared to the amount produced by the control group.

 

  • You are a part of the first scientific team to land on Mars. What steps would you take to determine whether there is any life there? If you found something, how would you know whether it is a living thing?

 

Answer: First, you would explore the landscape to discover anything that appeared to be alive. Then, using the scientific method to devise controlled experiments, as well as calling on your knowledge and definition of life on Earth, you would determine whether the things you have discovered are alive.

 

 

 

 

10

 

  • What is meant by the statement “science is measurement”?

 

Answer: The tools of science typically require some sort of measurement or calculation. As our tools become improved, our science becomes improved.

 

  • What is the purpose of the “control” in a controlled experiment?

 

Answer: The control will have only one variable compared to the treatment group. The control group provides a basis for comparison.

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

  • Which level of organization is the most inclusive? Which is the least inclusive?

 

Answer: The biosphere is the most inclusive because it includes all the other levels. The level of the atom is the least inclusive.

 

  • Name three ways that science and technology enrich your life today.

 

Answer: After reading the chapter, students should be familiar with some of the benefits of science and technology and should be able to give many different examples. Examples could include the availability of modern medicines; electricity and electronics, such as television and telephones; modern transportation; refrigeration.

 

  • Explain the difference between a theory and a hypothesis, and give an example of each.

 

Answer: A hypothesis is a statement of fact yet to be proven, whereas a theory is based on much work and compelling evidence. Student examples will vary. Theories could include the Big Bang, evolution, atomic theory, relativity, etc.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • What was the purpose in breaking off the dust trap or tilting the flask in Pasteur’s experiment?

 

Answer: To provide a control to show that microbes need to enter the flask from the outside for there to be growth.

 

  • Using what you have learned in this chapter, explain how you would decide whether multivitamins are beneficial to dogs.

 

Answer: Use the scientific method to devise controlled experiments to subject two groups of dogs to multivitamins.

 

  • Evaluate the statement “Nothing in biology makes sense unless it is studied in the light of evolution.”

 

Answer: Evolution is the chief unifying principle of biology that explains both the unity and diversity of life. Evolution shows how all life is connected and, at the same time, explains why there are so many different kinds of living things.

 

 

12

Exam

 

Name___________________________________

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Glycogen is used to store ________ in the ________. 1)
A) protein; muscle
B) nucleic acids; liver
C) glucose; spleen
D) protein; liver
E) glucose; liver
Answer: E
Explanation: A)
B)
C)
D)
E)
2) In some vintage science fiction movies, space travelers find themselves on a planet orbiting a 2)
distant star in which there are curious forms of life based on silicon instead of carbon. Although the
story clearly is sci-fi, there is an aura of plausibility in the choice of silicon, an atom with 14
protons, in place of carbon as this alien life-form’s central atom. The reason is that silicon:
A) is an isotope of carbon.
B) is lighter than carbon.
C) is heavier than carbon.
D) has four electrons in its outermost shell.
E) has one more proton than carbon, so is very similar to it.
Answer: D
Explanation: A)
B)
C)
D)
E)
3) In many cases, carbohydrates have the following ratio of elements: 3)
A) carbon and hydrogen in a ratio of 1:2.
B) carbon, hydrogen, and oxygen in a ratio of 1:2:1.
C) carbon, hydrogen, and oxygen in a ratio of 2:1:2.
D) carbon, hydrogen, and nitrogen in a ratio of 1:2:1.
E) carbon, oxygen, and hydrogen in a ratio of 1:2:1.
Answer: B
Explanation: A)
B)

C)

D)

E)

 

 

 

 

 

 

 

 

 

1

 

4) Alpha helices and beta pleated sheets are examples of: 4)
A) secondary structure.
B) primary structure.
C) tertiary structure.
D) quaternary structure.
Answer: A
Explanation: A)
B)
C)
D)
5) The monomers of polysaccharides are: 5)
A) amino acids.
B) lipids.
C) steroids.
D) nucleotides.
E) sugars.
Answer: E
Explanation: A)
B)
C)
D)
E)
6) The monomers of polysaccharides are: 6)
A) amino acids.
B) nucleotides.
C) simple sugars.
D) fatty acids.
Answer: C
Explanation: A)
B)
C)
D)
7) Which of the following is the indigestible (at least for humans) glucose polysaccharide that is found 7)
in plants?
A) starch
B) glycogen
C) chitin
D) cellulose
Answer: D
Explanation: A)
B)

C)

D)

 

 

 

 

 

 

 

 

 

2

 

8) Saturated fats are usually found in: 8)
  1. canola oil.
  2. a beef steak.
  3. safflower oil.
  4. both coconut oil and a beef steak.
  5. coconut oil.

 

Answer: D

Explanation:      A)

B)

C)

D)

E)

 

9) The difference between one amino acid and another is the: 9)
  1. type of R group each contains.
  2. difference in the chemical properties of their amino and carboxyl groups.
  3. way their amino groups bond with carboxyl groups.
  4. number of amino and carboxyl groups each contains.
  5. number of R groups each contains.

 

Answer: A

Explanation:      A)

B)

C)

D)

E)

 

10) Every protein has a unique shape and function because: 10)
  1. each protein has a unique sequence of nucleotides.
  2. the number of nitrogen atoms in each amino acid differs.
  3. each protein has a unique sequence of amino acids.
  4. the bonds between the amino acids vary from protein to protein.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

11) What do wax and testosterone have in common? 11)
  1. A) They are both lipids.
  2. B) They are both hormones.
  3. C) They are both steroids.
  4. D) They are both proteins.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

3

 

12) Butane and isobutane are isomers. This means they have the same: 12)
  1. chemical formula but a different arrangement of atoms.
  2. number of carbon atoms but different numbers of hydrogen atoms.
  3. chemical formula but can only exist as ring structures.
  4. arrangement of atoms but a different chemical formula.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

13) A functional group added to a hydrocarbon usually makes the hydrocarbon: 13)
  1. A) nonpolar.
  2. B) acidic.
  3. C) hydrophobic.
  4. D) an isomer.
  5. E) polar.

 

Answer: E

Explanation:      A)

B)

C)

D)

E)

 

  • Proteins that are composed of more than one polypeptide chain are said to have ________ structure. 14)

 

  1. primary
  2. tertiary
  3. secondary
  4. quaternary

 

Answer: D

Explanation:      A)

B)

C)

D)

 

15) If you removed the cuticle from the skin of an apple, the: 15)
  1. A) apple would be inedible.
  2. B) apple would lose water and dehydrate.
  3. C) seeds of the apple would die.
  4. D) apple would absorb moisture and get soggy.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

4

 

16) Which of the following contains both a carboxyl group and an amino group? 16)
A) lipids
B) nucleotides
C) carbohydrates
D) amino acids
Answer: D
Explanation: A)
B)
C)
D)
17) Which of the following are polysaccharides? 17)
A) starch and glycogen
B) sucrose and glucose
C) fructose and deoxyribose
D) DNA and RNA
Answer: A
Explanation: A)
B)
C)
D)
18) Which of the following is true of cellulose? 18)
  1. Animals store glucose as cellulose.
  2. Plants store amino acids as cellulose.
  3. Plants’ cell walls are made up of cellulose.
  4. Plants store glucose as cellulose.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

19) Unique chemical groups that confer special properties to an organic molecule are called: 19)
  1. A) functional groups.
  2. B) monomers.
  3. C) amino acids.
  4. D) lipids.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

20) In the following chemical reaction, which molecule is the disaccharide? 20)

glucose + fructose    sucrose + water

  1. A) glucose
  2. B) fructose
  3. C) sucrose
  4. D) water

 

Answer: C

Explanation:      A)

B)

C)

D)

 

21) Unsaturated fatty acids: 21)
  1. contain the maximum number of hydrogen atoms possible.
  2. have long been linked with heart disease.
  3. are usually found in animal fats.
  4. have one or more double bonds between the carbons.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

22) Nucleotides are the building blocks for: 22)
  1. A) lipids.
  2. B) steroids.
  3. C) proteins.
  4. D) disaccharides.
  5. E) ATP, DNA, and RNA.

 

Answer: E

Explanation:      A)

B)

C)

D)

E)

 

23) Carbon is such an important element for life because it: 23)
  1. can hydrogen bond to many different molecules.
  2. can form chemical bonds with a maximum of four other atoms.
  3. does not form isomers.
  4. forms strong ionic bonds.
  5. is part of the water molecule.

 

Answer: B

Explanation:      A)

B)

C)

D)

E)

 

 

 

 

 

 

 

6

 

24) All of the following are functions of proteins except: 24)
A) enzyme activity.
B) serving as transport molecules.
C) storing genetic information.
D) hormone activity.
E) serving as structural building materials.
Answer: C
Explanation: A)
B)
C)
D)
E)
25) An example of an important biological molecule that may contain the -NH2 group is: 25)
A) an enzyme.
B) a glucose molecule.
C) a starch.
D) a triglyceride.
E) steroids.
Answer: A
Explanation: A)
B)
C)
D)
E)
26) Which of the following lipids is the primary component in cell membranes? 26)
A) glycerol
B) steroids
C) phospholipids
D) triglycerides
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

27) Before DNA was established as the genetic material, proteins were considered the most likely 27)
molecules to serve this role. In part this belief was based on the fact that there are 20 building
blocks (20 different kinds of amino acids) for proteins versus 4 building blocks (4 different
nucleotides) for DNA. If proteins stored a code, there would be a far greater number of code words
possible for a protein of a given number of amino acids than for a DNA molecule of the same
number of nucleotides. For example, there are 16 different sequences (42) possible for a DNA two
nucleotides long and 400 (202) different sequences possible for a protein two amino acids long. For
a sequence three nucleotides or three amino acids in length, the number of distinct DNA sequences
is ________, and the number of distinct protein sequences is ________.
A) 64; 8,000
B) 800; 8,000
C) 64; 800
D) 20; 420
E) 30; 800
Answer: A
Explanation: A)
B)
C)
D)
E)
28) Which of the following is the correct order for the flow of information in the cell? 28)
A) DNA codes for protein, which codes for RNA.
B) Proteins code for DNA, which codes for RNA.
C) DNA codes for RNA, which codes for protein.
D) RNA codes for DNA, which codes for protein.
Answer: C
Explanation: A)
B)
C)
D)
29) Amino acids are monomers used to build: 29)
A) triglycerides.
B) nucleic acids.
C) polysaccharides.
D) proteins.
Answer: D
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8

 

30) Sugar is an organic molecule because it contains: 30)
A) carbon and oxygen.
B) carbon.
C) carbon and nitrogen.
D) water.
E) carbon dioxide.
Answer: B
Explanation:   A)
B)
C)
D)
E)
31) Which of the following is an example of a lipid? 31)
A) cellulose
B) cholesterol
  1. C) chitin
  2. D) keratin

 

Answer: B

Explanation:      A)

B)

C)

D)

 

32) Butter, which is made from milk fat, tends to be harder at room temperature than most margarines.      32)

If you wanted to make a butter that is softer at room temperature, you should consider:

  1. adding more than three fatty acid chains to the triglycerides.
  2. saturating the fatty acid chains.
  3. creating more double bonds in the fatty acid chains.
  4. making the fatty acid chains longer.
  5. making fatty acid chains with fewer kinks.

 

Answer: C

Explanation:      A)

B)

C)

D)

E)

 

33) The hydrogenation of vegetable oil results in: 33)
  1. a decrease in the number of double bonds between the carbon atoms.
  2. the oil becoming more liquid at room temperature.
  3. the conversion of monounsaturated fatty acids into polyunsaturated fatty acids.
  4. a decrease in the number of hydrogen atoms in the oil molecule.
  5. an increase in the number of double bonds between the carbon atoms.

 

Answer: A

Explanation:      A)

B)

C)

D)

E)

 

 

 

 

9

 

34) Chitin and cellulose are examples of: 34)
A) structural polysaccharides.
B) monosaccharides.
C) storage polysaccharides.
D) disacchrides.
Answer: A
Explanation: A)
B)
C)
D)
35) What do polysaccharides, such as cellulose; nucleic acids, such as DNA; and proteins, such as 35)
keratin, have in common?
A) They are all carbohydrates.
B) They are all amino acids.
C) They are all built of chemically linked monomers.
D) They are all lipids.
E) They are all nonpolar.
Answer: C
Explanation: A)
B)
C)
D)
E)
36) Which of the following is true of steroids? 36)
  1. Steroids exist naturally in humans as hormones.
  2. Steroids are polymers.
  3. Steroids contain a central, single-ring carbon structure.
  4. Some amino acids are steroids.
  5. If people inject male steroid hormones, they can build muscle mass with no side effects.

 

Answer: A

Explanation:      A)

B)

C)

D)

E)

 

37) The two chains of nucleotides in a DNA molecule are held together by: 37)
  1. A) covalent bonds.
  2. B) hydrogen bonds.
  3. C) peptide bonds.
  4. D) ionic bonds.
  5. E) hydrophobic interactions.

 

Answer: B

Explanation:      A)

B)

C)

D)

E)

 

 

 

 

10

 

38) Which of the following is a polymer? 38)
A) wax
B) nucleic acid
C) fat
D) steroid
Answer: B
Explanation: A)
B)
C)
D)
39) All of the following are monosaccharides except: 39)
A) glucose.
B) fructose.
C) deoxyribose.
D) cellulose.
Answer: D
Explanation: A)
B)
C)
D)
40) Many features of a protein change when it is moved into an environment with a different pH. 40)
Which of the following features would stay the same?
A) tertiary structure of the protein
B) amino acid sequence of the protein
C) binding properties of the protein
D) function of the protein
E) shape of the protein
Answer: B
Explanation: A)
B)
C)
D)
E)

 

41) You notice that water is running off the feathers of a bird in the rain. The reason is probably that the 41) bird has coated the feathers with ________, which keeps the water out of them.

 

  1. proteins
  2. nucleic acids
  3. lipids
  4. polysaccharides

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

11

 

42) Hydroxyl groups are commonly found in: 42)
  1. A) amino acids.
  2. B) carbohydrates.
  3. C) fatty acids.
  4. D) DNA.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

43) What is a triglyceride? 43)
  1. a lipid made of two glycerols, a fatty acid, and a phosphate group
  2. a lipid made of one glycerol and two fatty acids
  3. a lipid made of one glycerol and three fatty acids
  4. a polypeptide made of three amino acids
  5. a carbohydrate made of three sugars

 

Answer: C

Explanation:      A)

B)

C)

D)

E)

 

44) Glycogen is a polysaccharide used for energy storage by: 44)
A) animals.
B) fungi.
C) plants.
D) monera.
Answer: A
Explanation: A)
B)
C)
D)
45) A triglyceride contains ________ fatty acid chains, whereas a phospholipid contains ________ fatty 45)
acid chains.
A) two; three
B) three; two
C) four; two
D) two; four
Answer: B
Explanation: A)
B)

C)

D)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

46) Keratin is an example of a ________ protein. 46)

 

Answer: structural

Explanation:

 

 

12

 

47) The precursor from which steroid hormones are made is ________. 47)
Answer: cholesterol
Explanation:
48) You have a genetic defect that prevents your cells from making the amino acid tryptophan 48)
from indole and serine. Your cells might be lacking the proper information in their
________, which would direct the synthesis of the ________ that catalyzes tryptophan
synthesis.
Answer: DNA; enzyme
Explanation:
49) A series of amino acids linked in linear fashion is called a ________. 49)
Answer: polypeptide
Explanation:
50) If you boil an egg for lunch, the egg white becomes hard, white, and opaque because the 50)
protein molecules have unfolded, causing them to stick together. This is an example of
how heat ________ a protein.
Answer: denatures
Explanation:
51) ATP (adenosine triphosphate) is an energy-carrying, modified ________. 51)
Answer: nucleotide
Explanation:
52) Polypeptides differ in their ________ and ________ of amino acids. 52)
Answer: number; kinds
Explanation:
53) Ribosomes are made up of protein and ________. 53)
Answer: RNA
Explanation:
54) The active site of an enzyme is a product of its ________. 54)
Answer: three-dimensional shape or conformation
Explanation:
55) ________ is a branch of chemistry that studies carbon compounds. 55)
Answer: Organic chemistry
Explanation:

 

TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.

 

56) Hydroxyl groups are functional groups found on amino acids.

 

Answer:       True       False

Explanation:

 

57) Cholesterol is used to make other steroids in the body.

 

Answer:   True               False

Explanation:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

56)

 

 

 

 

57)

 

 

 

13

 

58) All other levels of protein structure are dictated by the primary structure. 58)
Answer: True False
Explanation:
59) Amino acids contain both amino and carboxyl functional groups. 59)
Answer: True False
Explanation:
60) Wax is a lipid. 60)
Answer: True False
Explanation:
61) All hormones are steroids. 61)
Answer: True False
Explanation:
62) Lipids with carbon-carbon double bonds tend to be more solid at room temperature. 62)
Answer: True False
Explanation:
63) The chitin that makes up the exoskeleton of insects is a polymer of amino acids. 63)
Answer: True False
Explanation:
64) Your muscles contract using contractile proteins to produce movement. 64)
Answer: True False
Explanation:
65) Glycogen is the carbohydrate found in plant cell walls. 65)
Answer: True False
Explanation:
66) Most enzymes are proteins, but not all proteins are enzymes. 66)
Answer: True False
Explanation:
67) Water is an organic molecule. 67)
Answer: True False
Explanation:
68) Both men and women make testosterone. 68)
Answer: True False
Explanation:
69) A nucleotide is a polymer of nucleic acids. 69)
Answer: True False

Explanation:

 

 

 

 

 

 

14

 

MATCHING. Choose the item in column 2 that best matches each item in column 1.

 

Match column 1 with the items in column 2.
70) A carbohydrate polymer A) structural proteins 70)
Answer: C
B) DNA
71) Found in hair and cartilage
71)
Answer: A C) polysaccharide
72) Serve as cell surface receptors D) glycoproteins 72)
Answer: D
73) The primary information-bearing E) lipoproteins
73)
molecule of life
Answer: B
74) Transport fats throughout the body 74)

Answer: E

 

ESSAY. Write your answer in the space provided or on a separate sheet of paper.

 

  • Describe the structure of phospholipids, and state where they are found in cells.

 

Answer: Phospholipids have hydrophobic tails and hydrophilic heads. This allows them to form a layer in which the hydrophilic heads will point toward water outside and the hydrophobic tails point away from the water and associate with the hydrophobic tails of other phospholipids. Phospholipids are largely found in the outer membrane of a cell.

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • Explain why you will always find an amino group at one end of a polypeptide chain and a carboxyl group at the other end.

 

Answer: The first amino acid will have an amino group on one side, and its carboxyl group will link up with the amino group of the next amino acid. The last amino acid in any polypeptide chain will be attached by its amino group and have its carboxyl group free.

 

 

 

 

 

 

 

15

 

  • Name the four most important groups of biological molecules necessary for life. List one polymer and one monomer of each.

 

Answer: Carbohydrates, lipids, proteins, and nucleic acids are the four groups. Examples for the polymers and monomers will vary, such as starch and glucose, fats and fatty acids, hemoglobin and amino acids, DNA and nucleotides.

 

  • You go the store to buy some lard for cooking. You notice when you get home that the lard is solid at room temperature. What does this tell you about the fat in lard, and how does this explain it being solid at room temperature? What type of fat would not be solid at room temperature, and why?

 

Answer: Lard is made up of saturated fat that stacks up when cool, thereby forming solids. Unsaturated fat has kinks caused by carbon-carbon double bonds, which prevents it from stacking, so it remains liquid at room temperature.

 

  • Mutations are changes to the information in DNA. What would happen to an enzyme’s ability to function if a mutation changed the order of some of the amino acids in its polypeptide chain?

 

Answer: Like all proteins, the function of an enzyme depends on its shape. The shape of an enzyme is primarily determined by its amino acid sequence. A mutation that changes the amino acid sequence would change the shape of the protein and therefore change or destroy the enzyme’s ability to function.

 

  • Explain the relationship between DNA and proteins.

 

Answer: DNA is the primary information-bearing molecule that directs the ordering of amino acids into a polypeptide chain.

 

  • Why are proteins, polysaccharides, and nucleic acids considered polymers, but lipids are not?

 

Answer: A polymer is made up of many similar or identical subunits. Proteins, polysaccharides, and nucleic acids are made up of individual monomers linked together to form larger molecules. Lipids are not polymers because they are not composed of many similar structural units linked together to form a large molecule.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • Phospholipids can be made to mix with water if mixed vigorously enough. Predict what kind of structure would be produced based on the chemical characteristics of phospholipids if they are mixed vigorously with water. If water exists outside a cell and water exists inside a cell, propose a way that phospholipids can be used to create a cell membrane.

 

Answer: In order to mix with water, phospholipids would have to form a sphere in which the hydrophilic head groups are on the surface and the hydrophobic tails are pointing in toward each other. Two layers of phospholipids are needed to make a cell membrane. The hydrophilic head groups can point outward, toward each side where there is water, and the hydrophobic tails of one layer would point toward the hydrophobic tails of the other layer.

 

  • Explain how a protein ends up with its final shape.

 

Answer: The amino acid sequence determines how the polypeptide folds into its secondary structure, the secondary structures come together to form the tertiary structure, and if there is more than one polypeptide involved, the protein will have quaternary structure.

 

 

 

 

Exam

 

Name___________________________________

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which statement is true of mitosis and cytokinesis in normal tissues? 1)
A) Cytokinesis precedes mitosis.
B) Mitosis precedes cytokinesis.
C) Cytokinesis occurs simultaneously with mitosis.
D) Cytokinesis partially overlaps with mitosis.
Answer: D
Explanation: A)
B)
C)
D)
2) Why do karyotypes always show chromosomes at the point when cell division is about to occur? 2)
A) This is the time at which the chromosomes are being duplicated.
B) This is the only cell cycle point in which the chromosomes are unduplicated.
C) The chromosomes are easier to see when they are elongated and uncondensed.
D) The chromosomes are fully condensed as cell division approaches.
Answer: D
Explanation: A)
B)
C)
D)
3) The study of physical inheritance among living things is: 3)
A) genetics.
B) genomics.
C) reproduction.
D) proteomics.
Answer: A
Explanation: A)
B)
C)
D)
4) Which statement about binary fission is true? 4)
A) It occurs during S phase of the cell cycle.
B) It is the cell division process of prokaryotic cells.
C) It is the cell division process of both prokaryotic and eukaryotic cells.
D) It is part of interphase.
Answer: B
Explanation: A)
B)

C)

D)

 

 

 

 

 

 

1

 

5) Which cell cycle stage is not part of interphase? 5)
A) G2
B) S
C) G1
D) M
Answer: D
Explanation: A)
B)
C)
D)
6) Which of the following structures is involved in forming a cleavage furrow? 6)
A) mitotic spindle
B) sister chromatids
C) metaphase plate
D) contractile ring
Answer: D
Explanation: A)
B)
C)
D)
7) The complete collection of an organism’s genetic information constitutes: 7)
A) a chromosome.
B) a gene.
C) proteins.
D) a genome.
Answer: D
Explanation: A)
B)
C)
D)
8) Chromosomes are aligned at the equator of a cell during: 8)
A) prophase.
B) anaphase.
C) telophase.
D) metaphase.
Answer: D
Explanation: A)
B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

9) A liver cell from a human male has: 9)
  1. 22 pairs of autosomes, an X chromosome, and a Y chromosome.
  2. 23 pairs of autosomes and two X chromosomes.
  3. 22 pairs of autosomes and two X chromosomes.
  4. 46 pairs of autosomes, an X chromosome, and a Y chromosome.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

10) Chromosome I from your mother and chromosome I from your father are said to be homologous. 10)
This is because the chromosomes:
A) appear the same size in a karyotype.
B) have different genes on them.
C) determine the sex of the child.
D) have the same genes on them.
Answer: D
Explanation: A)
B)
C)
D)
11) What would happen if the cell cycle proceeded normally except cytokinesis did not occur? 11)
A) Cells without nuclei would be formed.
B) A large cell with multiple nuclei would result.
C) The absence of cytokinesis would inhibit mitosis.
D) The G1 and G2 phases would become shorter.
Answer: B
Explanation: A)
B)
C)
D)
12) During S phase, chromosomes are converted to what form? 12)
A) sister chromatids
B) karyotypes
C) chromatin
D) centrosomes
Answer: A
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

3

 

13) The chromosomes become visible and the nucleus starts to break up during: 13)
  1. A) telophase.
  2. B) prophase.
  3. C) metaphase.
  4. D) anaphase.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

14) A karyotype: 14)
  1. can reveal the location of a gene.
  2. shows chromosomes as they appear before replication.
  3. can show the number of chromosomes in a cell.
  4. can reveal the presence of cancerous genes.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

15) The number of genes in the human genome is estimated to be: 15)
  1. A) 3 billion.
  2. B) 3 to 6 million.
  3. C) 1 million.
  4. D) 20,000 to 25,000.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

16) The “gap” phases of the cell cycle are devoted to: 16)
  1. moving chromosomes to their correct positions.
  2. creating new nuclei.
  3. DNA replication.
  4. normal cell operations, growth, and preparation for cell division.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

17) Which cell structure physically moves the cell’s chromosomes? 17)
  1. A) the cell wall
  2. B) the plasma membrane
  3. C) the contractile ring
  4. D) the mitotic spindle

 

Answer: D

Explanation:      A)

B)

C)

D)

 

18) The replication of a DNA molecule results in: 18)
  1. two DNA molecules, both of which are made of completely new strands.
  2. four unwound DNA strands.
  3. two DNA molecules, one being made of the old strands and one being made of two new strands.
  4. two DNA molecules, each with one old and one new strand.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

19) Sister chromatids are separating from each other during: 19)
  1. A) anaphase.
  2. B) prophase.
  3. C) telophase.
  4. D) metaphase.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

20) What would be the result of an error in anaphase that failed to separate a pair of sister chromatids?      20)

  1. The nuclear envelope would not be able to break down.
  2. One cell would have an extra gene, and one cell would be missing one gene.
  3. Cytokinesis would not be able to take place, and the cells would not divide.
  4. One cell would have an extra chromosome, and one cell would lack a chromosome.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

5

 

21) Normal cell operations and growth occur during the “gap” period called: 21)
A) G3.
B) G1.
C) S.
D) M.
Answer: B
Explanation: A)
B)
C)
D)
22) Which of the following organisms would reproduce by binary fission? 22)
A) bacteria
B) animals
C) plants
D) fungi
Answer: A
Explanation: A)
B)
C)
D)
23) What is one of the differences between cell division in plant cells and cell division in animal cells? 23)
  1. Plant cells do not use a mitotic spindle to separate chromosomes.
  2. There is no DNA replication before cell division in plant cells.
  3. Plant cells separate chromosomes by attachment to the plasma membrane.
  4. Plant cells separate by the formation of a new plasma membrane and cell wall in the middle of the cell.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

24) A cell plate is forming across the middle of a cell and new nuclei are forming at the poles. What 24)

kind of cell is this?

  1. A) a bacterial cell
  2. B) an animal cell going through cytokinesis
  3. C) a plant cell during metaphase
  4. D) a plant cell going through cytokinesis
  5. E) an animal cell during telophase

 

Answer: D

Explanation:      A)

B)

C)

D)

E)

 

 

 

 

 

 

 

 

6

 

25) If a cell contains 20 chromosomes, how many chromatids will be present during prophase? 25)
A) 20
B) 5
C) 40
D) 30
Answer: C
Explanation: A)
B)
C)
D)
26) At what point in the cell cycle does DNA replication take place? 26)
A) continually throughout the cell cycle
B) before mitosis
C) during cytokinesis
D) during mitosis
Answer: B
Explanation: A)
B)
C)
D)
27) Choose the statement that is correct about the frequency of mitosis. 27)
  1. Some cells, such as leaf cells, cease to divide after mature size is reached.
  2. Brain cells are easy to replace because they divide frequently after maturity.
  3. Bone marrow cells are an example of cells that cease to divide after maturity.
  4. All cells divide throughout the existence of a multicellular eukaryote.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

28) How do daughter cells at the end of mitosis and cytokinesis compare with the parent cell before 28)
DNA replication occurs?
  1. The daughter cells have half the number of chromosomes and half the amount of DNA.
  2. The daughter cells have half the amount of cytoplasm and half the number of chromosomes.
  3. The daughter cells have the same number of chromosomes and the same amount of DNA.
  4. The daughter cells may have the same number of chromosomes but double the amount of DNA.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

7

 

29) The information used to make proteins is encoded by the: 29)
A) number of different chromosomes.
B) four bases A, T, G, or C.
C) repeating sugar and phosphate molecules in DNA.
D) 20 different amino acids of proteins.
Answer: B
Explanation: A)
B)
C)
D)
30) A gene is a hereditary unit that carries information for: 30)
A) another gene.
B) a sequence of amino acids.
C) a sequence of nucleotides.
D) a sequence of sugars.
Answer: B
Explanation: A)
B)
C)
D)
31) A cell is observed under the microscope. What feature will indicate that it is in anaphase? 31)
A) Centrosomes are just beginning to separate and form the spindle.
B) Two separate nuclear membranes are visible.
C) Sister chromatids are separating.
D) DNA is elongated, not condensed, and difficult to visualize.
Answer: C
Explanation: A)
B)
C)
D)
32) Which of the following is the proper sequence of events in gene expression? 32)
A) DNA   protein   mRNA
B) DNA   mRNA   protein
C) mRNA  DNA   protein
D) protein   DNA   mRNA
Answer: B
Explanation: A)
B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

8

 

33) What event typically begins in anaphase and is completed soon after the end of telophase? 33)
  1. A) interphase
  2. B) packing of DNA into well-defined chromosomes
  3. C) alignment of chromosomes at the cell equator
  4. D) cytokinesis

 

Answer: D

Explanation:      A)

B)

C)

D)

 

34) What distinguishes one gene from another? 34)
  1. the order of bases in the gene
  2. the length of the chromosome the gene is on
  3. the position of the gene on a chromosome
  4. the order of amino acids of which the genes are made

 

Answer: A

Explanation:      A)

B)

C)

D)

 

35) The order of bases in a gene is copied to make a/an: 35)
  1. A) gene.
  2. B) ribosome.
  3. C) amino acid.
  4. D) mRNA.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

36) What is a function of cell division? 36)
  1. to keep cell size small as multicellular organisms grow
  2. to allow cell size to increase to its maximum
  3. to allow mature leaves to increase in size
  4. to turn skin cells into hair cells

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

9

 

37) What is one of the similarities between prokaryotic and eukaryotic cell division? 37)
  1. At the end of cell division, nuclear membranes form around the chromosomes.
  2. One cell divides into four cells.
  3. Microtubules separate the chromosomes.
  4. DNA is unwound and duplicated by the same process.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

38) Some anticancer chemotherapy agents interfere with the proper functioning of microtubules. How 38)
do these anticancer chemotherapy agents work?
  1. Microtubules replicate DNA, so they inhibit chromosome duplication.
  2. They inhibit telophase because microtubules are required to form nuclear envelopes.
  3. They inhibit the contractile ring and prevent cell division.
  4. They inhibit the mitotic spindle and prevent cell division.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

39) While looking under a microscope, you see two neighboring daughter cells. One of the cells 39)

contains three chromosomes, and the other contains five. The parent cell normally contains four chromosomes. What could be the reason for the different number of chromosomes in the cells?

  1. The nuclear envelope did not dissolve, so mitosis could not occur at all.
  2. The division of sister chromatids of one chromosome did not occur properly during mitosis.
  3. Replication of DNA did not occur properly.
  4. The division of homologous chromosomes during meiosis II did not occur properly.

 

Answer: B
Explanation: A)
B)
C)
D)
40) If a cell with 16 chromosomes undergoes mitosis, how many chromosomes will each daughter cell 40)
have?
A) 32
B) 4
C) 16
D) 8
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

10

 

41) What is the relationship between DNA and chromatin? 41)
  1. Chromatin is the combination of DNA packaged around proteins.
  2. A chromatin is a unit of DNA whose sequence encodes a protein.
  3. Chromatin is the collection of proteins encoded by DNA.
  4. A chromatin is a DNA molecule that is separated during mitosis.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

42) If a cell with two nuclei were discovered, which of the explanations below would be true? 42)
A) Mitosis occurred without cytokinesis.
B) The cell remained in interphase continuously.
C) Cytokinesis occurred without mitosis.
D) Meiosis and mitosis both occurred.
Answer: A
Explanation: A)
B)
C)
D)
43) Chromosomes uncoil and new nuclei form during: 43)
A) prophase.
B) telophase.
C) anaphase.
D) metaphase.
Answer: B
Explanation: A)
B)
C)
D)
44) What is the relationship between genes and chromosomes? 44)
  1. A chromosome is a DNA molecule with many genes.
  2. Chromosomes are proteins that carry genes made of DNA.
  3. Genes are the proteins encoded by chromosomes.
  4. Genes are the proteins around which DNA chromosomes are packaged.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

11

 

45) What would be the consequence if one base were changed in the base sequence of a DNA 45)
molecule?
A) Messenger RNA would correct the mistake.
B) Protein synthesis would stop.
C) A defective protein could be produced.
D) Genome copying would be impossible.
Answer: C
Explanation: A)
B)
C)
D)
46) Microtubule-organizing centers will begin to migrate toward the cell poles during: 46)
A) prophase.
B) anaphase.
C) telophase.
D) metaphase.
Answer: A
Explanation: A)
B)
C)
D)
47) A cell is observed under the microscope. What feature will indicate that it has just reached the end 47)
of interphase?
A) a visible contractile ring
B) elongated, noncondensed chromosomes that are difficult to visualize
C) two separate cells
D) chromosomes that are becoming well defined and visible
Answer: D
Explanation: A)
B)
C)
D)
48) Which molecule is made in the nucleus but exits to function in the cytoplasm? 48)
A) protein
B) chromosome
C) mRNA
D) gene
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

12

 

49) Why is prokaryotic cell division fundamentally different from eukaryotic cell division? 49)
  1. Prokaryotic cells divide for several months and then live for decades without dividing.
  2. Prokaryotic cells have a single chromosome and no nuclear membrane.
  3. Prokaryotes have many more chromosomes to divide.
  4. Prokaryotic cells do not have a plasma membrane.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

50) During DNA replication, what acts as the template for synthesis of a new strand of DNA? 50)
A) a single strand of mRNA
B) a ribosome
C) a single strand of DNA
D) a single strand of rRNA
Answer: C
Explanation: A)
B)
C)
D)
51) What is being separated during anaphase of mitosis? 51)
A) cytoplasm
B) nuclear membranes
C) plasma membranes
D) sister chromatids
Answer: D
Explanation: A)
B)
C)
D)
52) During metaphase, chromosomes that are attached to microtubules are observed to undergo a 52)
“back-and-forth” movement. What is happening during this movement?
A) The chromosomes are breaking up the nuclear membrane.
B) The centrosome is being replicated.
C) The chromosomes are being replicated.
D) The chromosomes are being aligned at the equator of the cell.
Answer: D
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

13

 

  • What is the initial step in DNA replication?
    1. formation of the mitotic spindle
    2. formation of the cleavage furrow
    3. unwinding of the DNA double helix
    4. breakdown of the nuclear envelope

 

Answer: C

Explanation:      A)

B)

C)

D)

 

  • The ordering of bases in a gene determines the order of:
    1. amino acids in a protein.
    2. genes in a genome.
    3. mRNAs on a ribosome.
    4. genes on a chromosome.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

55) In cell division, the separation of the cell’s cytoplasm to produce two daughter cells is 55)
________.
Answer: cytokinesis
Explanation:
56) The ________ of an organism is its complete collection of genetic information. 56)
Answer: genome
Explanation:
57) The sequence of events from the birth of a cell to when it divides describes the ________. 57)
Answer: cell cycle
Explanation:
58) In cell division, the separation of duplicated chromosomes is ________. 58)
Answer: mitosis
Explanation:
59) The ________ is a microtubule structure that binds to sister chromatids to separate them in 59)
anaphase.

 

Answer: mitotic spindle

Explanation:

53)

 

 

 

 

 

 

 

 

 

 

 

 

54)

 

 

 

 

 

 

 

 

 

 

14

 

TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.

 

60) During the cell cycle of a eukaryotic cell, each chromosome is replicated to become a chromosome 60)
with two chromatids, and then the chromatids are pulled apart to form two separate chromosomes.
Answer: True False
Explanation:
61) The human genome is estimated to include 20,000 to 25,000 genes. 61)
Answer: True False
Explanation:
62) Bacterial binary fission is essentially the same process as mitosis in animals and plants. 62)
Answer: True False
Explanation:
63) When a dividing human cell reaches telophase, 23 nuclear membranes must form, one for each pair 63)
of chromosomes.
Answer: True False
Explanation:
64) Compact chromosomes first become visible during metaphase. 64)
Answer: True False
Explanation:
65) Anaphase is characterized by the separation of sister chromatids. 65)
Answer: True False
Explanation:
66) The chief accomplishment of telophase is the organization of chromosomes into new nuclei. 66)
Answer: True False
Explanation:
67) During the cytokinesis phase of cell division, plant cells develop a cell plate instead of a cleavage 67)
furrow.
Answer: True False

Explanation:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

15

 

MATCHING. Choose the item in column 2 that best matches each item in column 1.

 

 

Match column 1 with the items in column 2.

  • The nuclear envelope has disappeared completely and sister chromatids are facing opposite poles

 

Answer: A

 

  • A contractile ring is narrowing along the cell’s equator

 

Answer: E

 

  • Chromosomes condense and the mitotic spindle begins to form Answer: D
  1. A) metaphase

68)

 

  1. anaphase

 

  1. telophase

 

69)

 

  1. prophase

 

  1. cytokinesis

70)

 

71) Microtubules shorten and the genetic

71)

material divides

 

Answer: B

72) Chromosomes unwind and new nuclei

72)

form

 

Answer: C

 

ESSAY. Write your answer in the space provided or on a separate sheet of paper.

 

  • At several points in the cell cycle there are checkpoints that control the cell’s passage from one phase to the next. If a cell receives a signal at each checkpoint, it continues to the next phase; if it does not receive the signal, the cell does not continue. For example, a growth factor may stimulate a cell to move from G1 into S phase. If no growth factor is present, the cell cycle stops in G1 and the cell does not divide. Predict what would happen to a cell and to a multicellular organism if there was a defect at the checkpoint and the cell continued through the cell cycle even in the absence of a signal.

 

Answer: If a cell cycle checkpoint is defective, then the cell will continue to divide even when it’s not supposed to. This is uncontrolled cell division. In a multicellular organism this would lead to abnormal growths of cells, producing tumors and cancer.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • What is the advantage of chromatin coiling and condensing into tight structures before mitosis?

 

Answer: Compact bodies are much easier to manipulate during mitosis than are long, thin threads, and compact bodies prevent the chromosome from getting tangled and breaking.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

17

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • A cell that no longer needs to divide will remain in G0 But if an injury occurs to an organ, signals will tell the cell to return to the cell cycle to replace lost or damaged cells. To which point in the cycle will the cell return, and which phase would it enter next?

 

Answer: Cells would reenter the G1 phase, and the next phase it would go to is S phase.

 

  • List and briefly describe three differences between prokaryotic and eukaryotic cell division.

 

Answer: (1) Prokaryotic cells have a single circular chromosome–one piece of DNA instead of the several separate chromosomes of eukaryotic cells. Mitosis is not necessary to separate chromosomes, because they simply attach to the plasma membrane to be separated as the cell grows. (2) Prokaryotic chromosomes are not in a nucleus. There is no membrane around the cells to break up during chromosome division. (3)

Prokaryotic chromosomes are not separated by attachment to a microtubule spindle. They separate by attachment to the plasma membrane. (4) Prokaryotic cells do not separate by formation of a cleavage furrow. The cell wall and plasma membrane grow inward to eventually separate a single cell into two cells.

 

  • What is the relationship between genes and proteins, including the function of each?

 

Answer: Genes specify the amino acid sequence of proteins, whereas proteins carry out the cellular functions.

 

 

 

 

 

 

 

 

 

 

18

 

  • You are a physician treating a patient with cancer. Traditional chemotherapy has not been working on this patient, so you prescribe a new class of drugs called taxanes, which inhibit microtubule function. Your patient asks you how they work. How would you explain to your patient how these drugs work?

 

Answer: Microtubules are involved in moving chromosomes around during cell division. Taxanes are a class of drugs that interfere with the microtubules, preventing them from moving chromosomes, which stops cell division. Cancer is unregulated cell growth, so stopping cell division stops the growth of the cancer.

 

  • Human skin cells and human white blood cells of the immune system both perform protective functions. Skin cells function primarily in external physical protection, whereas white blood cells function primarily in internal protection. Nonetheless, both types of cells contain a complete copy of the human genome. Explain how cells can have the same genetic information and yet perform different functions. What prevents skin cells from making all the same proteins of a white blood cell?

 

Answer: Even though almost all cells contain the same genome, different genes are active in the different types of cells. In skin cells, only certain genes are transcribed to produce physically protective proteins. The genes encoding the specialized proteins of a white blood cell are not active, for example; they are not transcribed.

 

 

  • Each phase of the cell cycle takes a different amount of time for a cell to complete. The longer the length of the phase, the more likely you will find a cell in that phase. You are looking at some animal cells under the microscope, and you see cells at different phases of the cell cycle. You count how many are in each phase and find out that 90 percent are in interphase, 6 percent are in prophase, 1.5 percent are in metaphase, 0.5 percent are in anaphase, and 2 percent are in telophase. If the length of the cell cycle is 24 hours, how long does it take for the cells to go through each of these phases of the cell cycle?

 

Answer: If 90 percent of the cells are in interphase, then they spend 90 percent of the 24-hour cell cycle in interphase, which is 21.6 hours. Likewise, prophase takes 1.4 hours, metaphase takes 36 minutes, anaphase takes 12 minutes, and telophase takes 48 minutes.

 

  • During which phase of mitosis are the chromosomes aligned along the equator of the cell? Predict what would happen if a cell completed mitosis without first lining up all the chromosomes in the middle of the cell.

 

Answer: The chromosomes are aligned along the equator of the cell during metaphase. The purpose of lining up chromosomes along the metaphase plate is to ensure that chromosomes are evenly divided between the two daughter cells. If the chromosomes are not lined up first, then there will likely be an uneven distribution of chromosomes, with one daughter cell having too many and the other daughter cell having too few.

 

 

Exam

 

Name___________________________________

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

Refer to the scenario below, and then answer the following question(s).

 

Two European men and two Polynesian women settled on a previously uninhabited tropical island. All four of the settlers have brown eyes, a dominant trait, but one of the Europeans is heterozygous and carries the recessive gene for blue eyes.

 

1) After several generations, 35 percent of the island population is found to have AB+ blood. This is 1)

much higher than the percentage of AB+ people in the populations from which the original settlers came. The high percentage of AB+ blood is probably due to:

  1. A) founder effect.
  2. B) selective mutation.
  3. C) nonrandom mating.
  4. D) disruptive selection.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

2) Which of these humans is the “fittest” as far as natural selection is concerned? 2)
  1. a person with seven children who is killed in an automobile accident at age 40
  2. a very popular film star who is still alive, is very rich, and has three children from three spouses
  3. a person who lives to the age of 105 and has two children
  4. a person who lives to the age of 110 and has no children

 

Answer: A

Explanation:      A)

B)

C)

D)

 

3) The most immediate effect of sexual displays and contests in animals (such as bighorn sheep 3)

bashing their heads together) is:

  1. A) differential mating success.
  2. B) stabilizing selection.
  3. C) disruptive selection.
  4. D) mutations.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

1

 

Read the statement below, and then answer the following question(s).

 

A small population of deer is introduced to an island. All the males have 11 to 13 points on their antlers.

 

4) If after several generations all males have 12-point antlers, this development will have been due to:       4)

  1. directional selection.
  2. founder effect.
  3. disruptive selection.
  4. stabilizing selection.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

5) Which of the following processes is not an agent of microevolution? 5)
A) natural selection
B) gene flow
C) polygenic inheritance
D) mutation
E) genetic drift
Answer: C
Explanation: A)
B)
C)
D)
E)
6) The term “natural selection” is not interchangeable with the term “evolution” because: 6)
A) natural selection does not always lead to evolution.
B) natural selection is just a theory, whereas evolution has been proven.
C) a population may evolve in ways other than through natural selection.
D) Darwin coined the term “natural selection,” but not “evolution.”
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

7) For the Galapagos Islands finch species Geospiza fortis, drought conditions produced a change in the 7) population in which the next generation had larger beaks than the previous one. What produced

 

this change in the population?

  1. Birds with smaller beaks flew to nearby islands where food was more plentiful.

 

  1. Birds with larger beaks had higher fitness, so they could produce more offspring that inherited the same trait.
  2. Birds with smaller beaks had higher fitness, but they waited to reproduce until wet weather returned.

 

  1. Birds with smaller beaks had higher fitness, but they were outcompeted by birds with larger beaks.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8) Human birth weights are an example of: 8)
  1. A) sexual selection.
  2. B) directional selection.
  3. C) stabilizing selection.
  4. D) disruptive selection.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

9) For a particular character, natural selection can favor an average phenotype or extreme 9)
phenotypes. In order to do this, a character must be:
A) not under the control of any genes.
B) under the control of many genes.
C) under the control of only two alleles for a gene.
D) controlled by a dominant allele for a gene.
Answer: B
Explanation: A)
B)
C)
D)
10) How have Caesarean sections and intensive neonatal (near-birth) medical care likely affected the 10)
average birth weight of American babies?
A) Gene flow will occur in the direction of larger and smaller infants.
B) Average birth weights have significantly decreased.
C) Stabilizing selection for birth weight no longer has as much of an influence.
D) Birth weight is now subject to disruptive selection instead of stabilizing selection.
Answer: C
Explanation: A)
B)
C)
D)
11) How successful an individual is at passing on its genes to the next generation is known as: 11)
A) microevolution.
B) fitness.
C) adaptation.
D) sexual selection.
Answer: B
Explanation: A)
B)
C)
D)
Read the statement below, and then answer the following question(s).
A small population of deer is introduced to an island. All the males have 11 to 13 points on their antlers.
12) If after several generations most males have antlers with 20 points, this development will have 12)
been the result of:
A) directional selection.
B) bottleneck effect.
C) founder effect.
D) disruptive selection.
Answer: A
Explanation: A)
B)
C)
D)

 

 

 

 

4

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

13) The changes in cranial capacity over the course of human evolution are an example of: 13)
A) stabilizing selection.
B) disruptive selection.
C) directional selection.
D) sexual selection.
Answer: C
Explanation:   A)
B)
C)
D)
14) If every sexually reproducing organism has only two alleles for each gene, how can there be a 14)
range of traits seen for a physical characteristic?
  1. One of the alleles in an organism is expressed at different levels, while the other is turned off.
  2. There can be more than two variations of a gene in a population.
  3. Sometimes one of the alleles works, and other times the other allele works.
  4. In a population there are only two variations of a gene, but they are blended differently during sexual reproduction.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

5

 

15) If within a large population no mutations occur, no migration occurs, all mating is random, and 15)

each individual has an equal chance of reproducing, which of the following will probably happen? A) No evolution will occur.

  1. B) A change in allele frequency will lead to rapid evolution.
  2. C) Extinction will occur.
  3. D) A bottleneck will occur.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

16) A bottleneck may be dangerous to a population because: 16)
  1. the potential for natural selection is greatly increased.
  2. mutation rate is decreased.
  3. mutation rate is increased.
  4. genetic variability is diminished.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

Refer to the scenario below, and then answer the following question(s).

 

Two European men and two Polynesian women settled on a previously uninhabited tropical island. All four of the settlers have brown eyes, a dominant trait, but one of the Europeans is heterozygous and carries the recessive gene for blue eyes.

 

17) No new settlers arrive, and nobody leaves the island. After a few generations, the percentage of 17)

blue-eyed individuals increases from the original zero to 25 percent. This is probably due to which of the following factors?

  1. A) mutation
  2. B) gene flow
  3. C) genetic drift

 

Answer: C

Explanation:      A)

B)

C)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6

 

Read the statement below, and then answer the following question(s).
A small population of deer is introduced to an island. All the males have 11 to 13 points on their antlers.
18) If after several generations 30 percent of the males have antlers with 9 to 11 points, 40 percent have 18)

antlers with 15 to 17 points, and 20 percent have antlers with 12 to 14 points, this development will have been the result of:

  1. A) disruptive selection.
  2. B) directional selection.
  3. C) founder effect.
  4. D) stabilizing selection.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

19) What is the difference between microevolution and macroevolution? 19)
  1. Microevolution describes changes within a population over a short period of time, whereas macroevolution describes larger changes such as the formation of new species over longer periods of time.
  2. Microevolution is hypothetical because changes are too small to be observed, whereas macroevolution is detectable.
  3. Microevolution deals with microscopic organisms, whereas macroevolution deals with larger ones.

 

  1. Microevolution describes what happens in small populations, whereas macroevolution deals with large populations.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

20) African black-bellied seedcracker finches have beaks that are either large or small. Only 20)

large-beaked birds can crack open hard seeds, and small-beaked birds are more adept at handling small seeds. Both have an advantage over intermediate-sized beaks. This is an example of a response to:

  1. A) stabilizing selection.
  2. B) directional selection.
  3. C) disruptive selection.
  4. D) sexual selection.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

7

 

21) In order for migration to alter allele frequencies in another population: 21)
  1. a large portion of the population must leave as new individuals arrive.
  2. the gene pool of the migrating population must be different from the population it is joining.
  3. the gene pools of the populations involved must be very similar.
  4. a large portion of the population must die off.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

22) Male guppies are known for their bright colors. Having bright colors attracts mates, but it also 22)
attracts predators. So in an environment with a lot of predators, male guppies have more dull
colors. In an experiment, guppies were removed from an area with predators to an area without
predators. Over a period of 12 months the population became much more colorful. This is an
example of a response to:
A) directional selection.
B) mutation.
C) disruptive selection.
D) stabilizing selection.
Answer: A
Explanation: A)
B)
C)
D)
23) The genetic makeup of any organism is its ________, which determines the physical characteristics 23)
called its ________.
A) gene pool; alleles
B) genotype; alleles
C) genotype; phenotype
D) phenotype; genotype
Answer: C
Explanation: A)
B)
C)
D)
24) Even though in a similar habitat, a founder population that breaks away from the parent 24)
population may become very different because of:
A) natural selection.
B) the bottleneck effect.
C) genetic drift.
D) mutation.
Answer: C
Explanation: A)
B)

C)

D)

 

 

 

 

 

 

8

 

25) Disruptive selection operates whenever: 25)
  1. the extremes in a distribution of phenotypes are more fit than the average.
  2. a phenotype is more successful because it is rare.
  3. only the largest individuals survive.
  4. natural selection is disrupted by genetic drift.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

26) Phenotypes that show a wide range of almost continuous variation, such as height or skin color in 26)
humans, are probably:
A) due to several sets of alleles working together.
B) due to both alleles of one gene working together.
C) dominant.
D) acquired characteristics.
Answer: A
Explanation: A)
B)
C)
D)
27) Shrews have been documented to travel across frozen lakes and establish populations on 27)
previously uninhabited islands; thus, the shrews have a limited gene pool. If this limited gene pool
has allele frequencies that are very different from the allele frequencies found in the original
population, then this would be an example of:
A) natural selection.
B) founder effect.
C) divergent evolution.
D) population bottleneck.
Answer: B
Explanation: A)
B)
C)
D)
28) Two nearby populations in which there is some movement of individuals between the populations 28)
are an example of:
  1. gene flow.
  2. bottleneck effect.
  3. disruptive selection.
  4. genetic drift.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

9

 

29) The formation of new species over many generations is an example of: 29)
A) gene pools.
B) macroevolution.
C) microevolution.
D) allelic variants.
Answer: B
Explanation: A)
B)
C)
D)
30) You are studying leaf size in a natural population of plants. The second season is particularly dry, 30)
and the following year the average leaf size in the population is smaller than the year before. But
the amount of overall variation is the same, and the population size hasn’t changed. Also, you’ve
done experiments that show that small leaves are better adapted to dry conditions than are large
leaves. Which of the following has occurred?
A) genetic drift
B) stabilizing selection
C) disruptive selection
D) directional selection
Answer: D
Explanation: A)
B)
C)
D)
31) Which of the following possibilities is the best indicator of an organism’s evolutionary fitness? 31)
  1. the number of gametes it produces during the years when it is likely to be reproducing
  2. the number of offspring it produces over its lifetime that survive to breed.
  3. the number of offspring it produces over its lifetime
  4. the number of eggs it produces over its lifetime

 

Answer: B

Explanation:      A)

B)

C)

D)

 

32) At its most basic level, evolution is a: 32)
  1. change in the frequency of alleles in an individual.
  2. change in an individual’s phenotype caused by mutations.
  3. new species arising from an existing species.
  4. change in the frequency of alleles in a population.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

10

 

33) Organisms that can interbreed with each other in nature but are genetically isolated from all other 33)

organisms are a:

  1. A) clone.
  2. B) family.
  3. C) species.
  4. D) genus.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

34) A population is: 34)
  1. all the different species that live in a defined geographic area at the same time.
  2. a group of different species that share common features.
  3. all the members of a species that live in a defined geographic region at the same time.
  4. a group of organisms that can successfully interbreed in nature but do not interbreed with other such groups.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

35) The only known population of a reptile species lives on an African mountain. The population is 35)

relatively large, but no close relatives of this species are known. Suppose you could stop all mutations within the population and all emigration out of this population. Which statement best describes the probable future of this population?

  1. The population will decline and become extinct after a few generations because of excessive inbreeding.

 

  1. Genetic drift will cause major evolutionary changes in the population.
  2. Evolution will continue as natural selection acts on the genetic variability that exists in the population.
  3. Although the population will cease to change, it may survive for as long as the environment remains constant.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

36) As world travel becomes easier and human populations intermix, the occurrence of what 36)

phenomenon will probably decrease?

  1. A) mutation
  2. B) immigration
  3. C) founder effect and genetic drift
  4. D) sexual selection

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

11

 

37) Which of the following is most likely to cause genetic changes in a population that make it better 37)
adapted to its environment?
A) gene flow
B) natural selection
C) genetic drift
D) nonrandom mating
Answer: B
Explanation: A)
B)
C)
D)
38) ________ is necessary for a population to survive over successive generations in response to 38)
environmental changes.
A) Speciation
B) Gene flow
C) Sexual selection
D) Adaptation
Answer: D
Explanation: A)
B)
C)
D)
39) Which of the following statements about evolution is true? 39)
  1. Evolution involves maintaining a constant frequency of alleles in the gene pool.
  2. Individuals evolve.
  3. Populations evolve.
  4. Evolution can proceed to a limited extent without the occurrence of mutation.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

40) Which of the following is incorrectly paired? 40)
  1. bottleneck effect: changes in allele frequencies due to chance events
  2. gene flow: genes move from one population to another
  3. founder effect: only a small portion of an original population’s gene pool are represented
  4. sexual selection: mating based on phenotype

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

12

 

41) The most important kind of selection acting on a well-adapted population in a relatively constant 41)
environment is:
A) stabilizing.
B) catastrophic.
C) disruptive.
D) directional.
Answer: A
Explanation: A)
B)
C)
D)
42) Extreme hunting pressure has caused northern elephant seals to become less genetically diverse 42)
because of:
A) population bottleneck.
B) natural selection.
C) founder effect.
D) genetic drift.
Answer: A
Explanation: A)
B)
C)
D)
43) Genetic drift occurs when: 43)
  1. the population has not yet stabilized.
  2. gene flow within the population is less than gene flow between populations.
  3. reproduction is nonrandom within the population.
  4. chance occurrences alter gene frequencies.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

44) The greater prairie chicken once flourished on the prairies of Illinois. The conversion of prairie to 44)

farmland reduced their numbers from millions to only 50 birds by 1993. Poor genetic diversity resulted in only 50 percent of eggs hatching. Bringing in birds from neighboring states increased their genetic diversity, which improved the egg-hatching rate to 90 percent. These changes in genetic diversity were the result of:

  1. loss of genetic diversity through genetic drift and restoration of genetic diversity by gene flow.

 

  1. loss of genetic diversity through genetic drift and restoration of genetic diversity by natural selection.

 

  1. loss of genetic diversity through mutation and restoration of genetic diversity by gene flow.
  2. loss of genetic diversity through natural selection and restoration of genetic diversity by genetic drift.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

13

 

45) Mutations: 45)
  1. account for most of the change in allele frequency in a population.
  2. are always detrimental.
  3. may do nothing, may be harmful, or may be beneficial.
  4. are always beneficial.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

46) Evolution by genetic drift is most obvious in: 46)
A) aquatic populations.
B) migratory species.
C) small populations.
D) invertebrate species.
Answer: C
Explanation: A)
B)
C)
D)
47) Habitats set aside for endangered species are often sectioned into areas by roads, producing 47)
separate small populations. This causes problems in conservation because it reduces:
A) interaction among generations.
B) sharing of resources.
C) gene flow between populations.
D) the number of potential leaders.
Answer: C
Explanation: A)
B)
C)
D)
48) The gene pool for a particular gene would include: 48)
  1. the sum of all the alleles for all the traits in the population.
  2. all the alleles for a given trait in a particular individual organism of the population.
  3. all the alleles for a particular gene in all the individuals in the population.
  4. the sum of all the phenotypes in the population.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

14

 

49) Which of the following statements is true? 49)
  1. The advantage a trait conveys depends on its environmental context.
  2. All traits currently in a population must have provided a reproductive advantage at some point in time.
  3. All traits are simultaneously maximized in a population.
  4. A population will always evolve to fit current conditions.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

50) Which of the following is ultimately responsible for introducing new alleles into a population? 50)
A) genetic drift
B) mutation
C) natural selection
D) sexual selection
Answer: B
Explanation: A)
B)
C)
D)
51) The mate-attracting elaborate plumage of the male peacock is a result of: 51)
A) genetic drift.
B) sexual selection.
C) gene flow.
D) adaptation to the environment.
Answer: B
Explanation: A)
B)
C)
D)
52) Imagine a population of monkeys in South America whose habitat has been reduced to the point 52)
where only 25 monkeys survive. This is an example of:
A) population bottleneck.
B) genetic drift.
C) natural selection.
D) founder effect.
Answer: A
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

15

 

53) Which of the following males in a given population would be considered the most fit in an 53)
evolutionary sense?
  1. one that produced 1,000 offspring, of which 100 survived but 99 did not reproduce
  2. one that produced 1,000 offspring, all of which died before reaching reproductive age
  3. one that produced 100 offspring, of which 10 survived but 9 did not reproduce
  4. one that produced two offspring, both of which survived and produced offspring of their own

 

Answer: D

Explanation:      A)

B)

C)

D)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

54) ________ characters are continuously variable. 54)
Answer: Polygenic
Explanation:
55) The original source of variation within a population comes from ________. 55)
Answer: mutations
Explanation:
56) In ________ selection, individuals with an intermediate phenotype are favored over other 56)
individuals in the population.
Answer: stabilizing
Explanation:
57) When a population decreases in number until a small remnant of the original population 57)
remains, a ________ has occurred.
Answer: bottleneck
Explanation:
58) The smallest unit that can participate in evolution is a ________. 58)
Answer: population
Explanation:

 

TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.

 

59) A population of salamanders migrates from a sand beach to a pebble beach and evolves over many 59)
generations from a solid color to speckled coloration. This process is called stabilizing selection.
Answer: True False
Explanation:
60) If a species of bird with an intermediate beak size evolves into two varieties, one with large beaks 60)
and one with small beaks, this could result from disruptive selection.
Answer: True False

Explanation:

 

 

 

 

 

 

 

 

16

 

  • Without mutation, evolution would eventually cease, because mutations create the variation that evolution acts upon.

 

Answer:   True               False

Explanation:

 

62) There can be more than two varieties of alleles for a particular gene in a population.

 

Answer:   True               False

Explanation:

 

63) Genetic drift has a much more significant effect on small populations than on large populations.

 

Answer:   True               False

Explanation:

 

64) The basic units that evolve are species.

 

Answer:       True       False

Explanation:

 

  • A small minority of mutations is adaptive, providing an improvement to the gene pool of the population.

 

Answer:   True               False

Explanation:

 

MATCHING. Choose the item in column 2 that best matches each item in column 1.

61)

 

 

 

 

 

62)

 

 

 

 

63)

 

 

 

 

64)

 

 

 

 

65)

 

 

Match column 1 with the items in column 2.

  • A small number of individuals from one area establish a new isolated population in another area. The gene frequencies of the new population differ from those of the original population.

 

Answer: B

 

  • Alleles migrate into or out of a population from neighboring populations.

 

Answer: D

 

  • Chance events change allele frequencies in populations. Answer: A

 

  • Individuals with average phenotypes are favored over those with extreme phenotypes.

 

Answer: C

 

  • Females tend to mate with brightly colored males.

 

Answer: E

 

  1. genetic drift

 

  1. founder effect

 

  1. stabilizing selection

 

  1. gene flow

 

  1. sexual selection

 

66)

 

 

 

 

 

 

 

 

 

67)

 

 

 

 

 

68)

 

 

 

 

69)

 

 

 

 

 

70)

 

 

 

17

 

ESSAY. Write your answer in the space provided or on a separate sheet of paper.

 

  • The concept of evolution has always been connected with some notion of progress–natural selection pushing populations toward better and better adaptations to create “perfect organisms.” How would you argue that evolution does not craft perfect organisms?

 

Answer: Natural selection adapts populations to their constantly changing environments. It acts on those more fit for their environments, but the environments may change over time. An organism is only more fit than others of its population at a particular time; the organism is not necessarily a perfect match for its environment and is not a perfect organism by human criteria. What constitutes a best match at one time may be a less perfect match as the environment changes.

 

  • Male long-tailed widowbirds have unusually long tails, about 20 inches in length, whereas the females have short tails. In an experiment with long-tailed widowbirds, one group of males had their tails clipped to 5 inches, a second group were left with normal 20-inch tails, and a third group had their tails lengthened to 30 inches by gluing on feathers clipped from the tails of other birds. If sexual selection is responsible for the males having such long tails, predict what will happen when similar numbers of females are placed in the territories of each group of males.

 

Answer: The males have longer tails because that characteristic was sexually selected for by females. One plausible hypothesis is that, because female preference is for longer tails, the males from the third group with 30-inch tails will attract more females.

 

  • List five mechanisms by which gene frequencies in a population can be altered. Describe each briefly.

 

Answer: Gene frequencies can be altered by mutation, which changes allele frequencies or creates new alleles; gene flow, which introduces new alleles into a population; genetic drift, which changes allele frequencies due to random events; natural selection, in which traits that confer a reproductive advantage grow more common in a population; and sexual selection, which produces differential reproductive success.

 

  • One solution to the problem of species extinction is captive breeding in zoos and gardens. What are some of the problems associated with this solution?

 

Answer: The resulting population, because it is small, will have a low genetic diversity. Such programs mimic the bottleneck effect unless efforts are made to increase diversity.

 

  • Cheetahs are not a healthy species. Several million years ago they were widespread in Africa and Asia, but their numbers fell drastically during the last ice age and again when they were hunted to near extinction in the nineteenth century. Now, they suffer from low survivorship (a large number of animals dying), poor sperm quality, and greater susceptibility to disease. Normally, an animal will reject tissue transplanted from another animal, but cheetahs will not reject tissue grafted on to them from another cheetah. What happened to the cheetah? How did their genetic variation change? Where does genetic variation ultimately come from? What mechanism can maintain and increase genetic variation in natural populations?

 

Answer: Cheetahs went through a bottleneck twice, once during the last ice age and again when they were hunted to near extinction. This caused a significant reduction in the genetic variation in their gene pool, and cheetahs now have very little genetic variation. With little genetic variation, the members of the species are all genetically very similar. Genetic variation ultimately comes from mutations, which produces new alleles. Genetic variation can be maintained and increased through gene flow.

 

 

 

Exam

 

Name___________________________________

 

 

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

 

1) The value of the three small bones of the middle ear is that they: 1)
  1. connect the eardrum to the nerves of hearing.
  2. translate vibration into nerve impulses.
  3. amplify vibrations by concentrating them into a smaller area.
  4. translate solid vibration into internal liquid vibration.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

2) Which part of the human eye detects colored light? 2)
A) enzymes in ganglion cells
B) aqueous humor
C) rhodopsin molecules
D) cornea
E) cones
Answer: E
Explanation: A)
B)
C)
D)
E)
3) Routine activities and energy conservation are controlled by the: 3)
A) peripheral nervous system.
B) thalamus.
C) parasympathetic division.
D) sympathetic division.
Answer: C
Explanation: A)
B)
C)
D)
4) Which of the following best describes the structural aspect of the cerebral cortex? 4)
A) a cap of white matter over the spinal cord, made mostly of the thalamus
B) a thick band of white matter making the outer layer of the cerebrum
C) a thin band of gray matter making the outer layer of the cerebrum
D) a core of fast, myelinated axons in the interior of the brain
Answer: C
Explanation: A)
B)

C)

D)

 

 

 

 

1

 

5) The cochlea is part of the: 5)
A) inner ear.
B) eye.
C) outer ear.
D) brain.
Answer: A
Explanation: A)
B)
C)
D)
6) Any collection of nerve cell bodies in the PNS is called a: 6)
A) ganglion.
B) dendrite.
C) afferent nerve.
D) efferent nerve.
Answer: A
Explanation: A)
B)
C)
D)
7) When light enters the eye, it is bent, or refracted, first by the: 7)
A) vitreous body.
B) cornea.
C) lens.
D) retina.
Answer: B
Explanation: A)
B)
C)
D)
8) Our “oldest” sense, which works in a very similar way in insects, is the sense of: 8)
A) vision.
B) smell.
C) hearing.
D) touch.
Answer: B
Explanation: A)
B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

9) A person is blindfolded and then given a piece of apple to eat while the scent of pineapple is 9)
wafted around his or her nose. The person would most likely guess that he or she is eating a/an:
A) pineapple.
B) new type of fruit.
C) 50-50 mixture of apple and pineapple.
D) apple.
Answer: A
Explanation: A)
B)
C)
D)
10) Which part of your brain processes the information in this question and, you hope, retrieves the 10)
information necessary to answer it?
A) cerebellum
B) cerebral cortex
C) pons
D) midbrain
E) hypothalamus
Answer: B
Explanation: A)
B)
C)
D)
E)
11) The parts of the central nervous system are the: 11)
A) nerves and receptors.
B) autonomic and somatic.
C) afferent and efferent.
D) brain and spinal cord.
Answer: D
Explanation: A)
B)
C)
D)
12) Which of the following would send a signal to the central nervous system that you had touched a 12)
hot object?
A) sensory neuron
B) glial cell
C) motor neuron
D) interneuron
Answer: A
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

3

 

13) Which of the following best describes sensory receptors? 13)
  1. Sensory receptors interpret sensation.
  2. Sensory receptors work through efferent pathways.
  3. Sensory receptors translate stimulation into action potentials.
  4. Sensory receptors translate action potentials into stimuli.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

14) How do hair cells of the cochlea translate vibration into nervous impulses? 14)
A) Pulling hairs trigger an action potential.
B) Bending cilia lead to ion flow and neurotransmitter release.
C) Vibrating hairs open voltage sensitive channels.
D) Moving cilia break molecules at their bases.
Answer: B
Explanation: A)
B)
C)
D)
15) Cells in the central nervous system that are important for functions such as memory are the: 15)
A) glial cells.
B) sensory neurons.
C) interneurons.
D) motor neurons.
Answer: C
Explanation: A)
B)
C)
D)
16) Part of the reason for the charge difference inside and outside a neuron’s membrane is: 16)
A) excess potassium outside the membrane.
B) positively charged proteins outside the membrane.
C) excess sodium inside the membrane.
D) negatively charged proteins inside the membrane.
E) positively charged proteins inside the membrane.
Answer: D
Explanation: A)
B)
C)
D)
E)

 

 

 

 

 

 

 

 

 

 

 

4

 

17) White matter areas of the nervous system mostly contain: 17)
A) myelinated axons.
B) cerebrospinal fluid.
C) ganglia.
D) neuron cell bodies.
Answer: A
Explanation: A)
B)
C)
D)
18) The portion of the nervous system that most directly controls skeletal muscles is the: 18)
A) parasympathetic.
B) autonomic.
C) somatic.
D) afferent.
E) sympathetic.
Answer: C
Explanation: A)
B)
C)
D)
E)
19) A section of a neuron’s membrane becomes temporarily positive on the inside when: 19)
A) negatively charged proteins exit the cell.
B) neurotransmitters enter the cell.
C) ion channels open and potassium ions rush in.
D) ion channels open and sodium ions rush in.
Answer: D
Explanation: A)
B)
C)
D)
20) Nerves would be best described as: 20)
  1. collections of sensory neuron dendrites and cell bodies.
  2. bundles of dendrites in the peripheral nervous system (PNS).
  3. bundles of axons in the peripheral nervous system (PNS).
  4. collections of motor neuron dendrites and cell bodies.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

5

 

21) The term “brain dead” may refer to the fact that all brain centers have ceased to function except the: 21)
A) hypothalamus.
B) cerebellum.
C) medulla oblongata.
D) thalamus.
E) cerebrum.
Answer: C
Explanation: A)
B)
C)
D)
E)
22) The cells of the nervous system that transmit nervous system messages are the: 22)
A) dendrites.
B) synapses.
C) neurons.
D) glial cells.
Answer: C
Explanation: A)
B)
C)
D)
23) The iris of the human eye is composed partly of: 23)
A) empty space.
B) connective tissue.
C) rods.
D) smooth muscle.
E) nervous tissue.
Answer: D
Explanation: A)
B)
C)
D)
E)
24) Inrushing sodium ions trigger the opening of nearby channels and movement of sodium inward at 24)
that neighboring section of the membrane. What is occurring?
A) normal resting potential
B) neurotransmitter release
C) an action potential
D) protein movement
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

6

 

25) An organ or group of cells that responds to a motor neuron is a/an: 25)
  1. A) glial cell.
  2. B) receptor.
  3. C) effector.
  4. D) sensory organ.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

26) The Pacinian corpuscle is important to: 26)
  1. the sense of touch.
  2. information about the position of the joints.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

27) Proprioceptors provide us with: 27)
  1. information about the position of the joints.
  2. the sense of touch.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

28) A drug that causes potassium to leak out of the neuron would: 28)
  1. make it harder to trigger action potentials in the neuron.
  2. cause the outside of the neuron to become more negative.
  3. cause the inside of the neuron to become more positive.
  4. make it easier to trigger action potentials in the neuron.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

29) Which of the following does the central nervous system use for the action of pulling your hand 29)

away from a hot object?

  1. A) motor neurons
  2. B) sensory neurons
  3. C) receptors
  4. D) glial cells

 

Answer: A

Explanation:      A)

B)

C)

D)

 

30) Which statement about the sense of smell in humans is most accurate? 30)
  1. Ciliated cells rapidly move scent molecules to the brain for rapid analysis.
  2. One hundred different receptor varieties allow us to discern about 100 scents.
  3. Smell is about equally as strong as taste.
  4. Combinations of over 300 receptors allow us to discern thousands of scents.

 

Answer: D

Explanation:      A)

B)

C)

D)

 

31) Which of the following would be a function of the sympathetic division? 31)
A) constrict the pupils
B) stimulate the gallbladder
C) accelerate heart rate
D) stimulate the stomach
Answer: C
Explanation: A)
B)
C)
D)
32) In a reflex such as the “knee jerk” or patellar reflex, the efferent signal travels through the: 32)
A) motor neuron.
B) sensory neuron.
C) spinal cord.
D) interneuron.
Answer: A
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

8

 

33) Most sensory information is routed through which structure before arriving in the cerebrum? 33)
A) medulla oblongata
B) midbrain
C) thalamus
D) pons
E) hypothalamus
Answer: C
Explanation: A)
B)
C)
D)
E)
34) Spinal nerves emerging from the spinal cord are named for: 34)
A) their basic function.
B) strictly the number sequence 1—30.
C) the portion of the vertebral column around them.
D) the organ they supply.
Answer: C
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

9

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

35) The missing label indicated by a “2” corresponds to the: 35)
  1. A) oval window.
  2. B) tympanic membrane.
  3. C) cochlea.
  4. D) malleus.

 

Answer: C

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

10

 

Refer to the figure below, and then answer the question that follows.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

36) The part of the brain indicated by a “1” corresponds to the: 36)
A) hypothalamus.
B) cerebellum.
C) thalamus.
D) medulla oblongata.
Answer: B
Explanation: A)
B)
C)
D)
37) You are giving first aid to a semiconscious person who (before your arrival) told a bystander 37)
something about taking a drug overdose. The person has dilated pupils and a dry mouth. You
recall reading that many drugs “mimic” the effects of nervous system functions, and you quickly
size up which part of the nervous system is being mimicked here. The bystander is calling 911. In
order to save time and best advise the emergency dispatcher about the treatment EMTs should be
prepared to begin when they arrive, you tell the bystander to tell the 911 operator that the drug
taken probably mimics which nervous system division?
A) sfferent
B) sympathetic
C) somatic
D) parasympathetic
Answer: B
Explanation: A)
B)
C)
D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11

 

38) Axons of motor neurons first leave the spinal cord through the: 38)
A) ventral roots.
B) dorsal roots.
C) spinal nerve.
D) dorsal root ganglion.
Answer: A
Explanation: A)
B)
C)
D)
39) The autonomic nervous system is a part of the: 39)
A) peripheral nervous system.
B) appendicular nervous system.
C) somatic nervous system.
D) central nervous system.
Answer: A
Explanation: A)
B)
C)
D)
40) Which statement best describes how one neuron stimulates another? 40)
  1. Calcium ions diffuse across the synapse.
  2. Neurotransmitter molecules diffuse across the synapse.
  3. Sodium ions jump across to the next neuron’s membrane.
  4. The neurons are physically connected, so the action potential continues movement.

 

Answer: B

Explanation:      A)

B)

C)

D)

 

41) The basic taste sensations are different in that each sensation works through: 41)
  1. A) a different chemical reaction route in a taste cell.
  2. B) different ciliated receptor varieties, just like smell receptors.
  3. C) different taste nerves.
  4. D) a similar chemical reaction route in a taste cell.

 

Answer: A

Explanation:      A)

B)

C)

D)

 

 

 

 

 

 

 

 

 

 

 

 

 

12

 

42) When a neuron is at its “resting potential,” which of the following is true about the concentration of 42)
sodium ions?
  1. The sodium concentration is the same outside and inside the neuron’s cell membrane.
  2. Sodium ions have a greater concentration outside the neuron’s cell membrane.
  3. Sodium ions have a greater concentration inside the neuron’s cell membrane.

 

Answer: B

Explanation:      A)

B)

C)

 

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.

 

43) In which layer of cells in the eye is light converted into an electrical signal? 43)
Answer: retina
Explanation:
44) Which division of the autonomic nervous system stimulates digestion? 44)
Answer: parasympathetic division
Explanation:
45) Motor neurons, which tell muscles to move, leave the spinal cord through the ________. 45)
Answer: ventral root
Explanation:
46) Which part of the brain is probably most involved with dreaming? 46)
Answer: the cerebrum
Explanation:
47) In which part of the inner ear are vibrations converted into action potentials? 47)
Answer: cochlea
Explanation:

 

TRUE/FALSE. Write ‘T’ if the statement is true and ‘F’ if the statement is false.

 

48) A nerve is larger than a neuron. 48)
Answer: True False
Explanation:
49) Different parts of the tongue are responsive to different tastes. 49)
Answer: True False
Explanation:
50) If the left side of the body is paralyzed by a stroke or other brain injury, the damage occurred on 50)
the left side of the brain.
Answer: True False
Explanation:
51) Our visual system creates images as well as perceiving them. 51)
Answer: True False

Explanation:

 

 

 

13

 

52) The action potential moves across the synaptic cleft as an electrical signal. 52)
Answer: True False
Explanation:
53) Voluntary movement of the legs is controlled by the somatic nervous system. 53)
Answer: True False
Explanation:
54) The brain and the spinal cord make up the central nervous system (CNS). 54)
Answer: True False
Explanation:
55) Damage to the medulla oblongata in the brain could interfere with breathing. 55)
Answer: True False
Explanation:
56) The neuron being stimulated by a neurotransmitter comes after the synaptic cleft. 56)
Answer: True False
Explanation:
57) The parasympathetic division of the autonomic nervous system would be key in preserving an 57)
individual who is escaping from a dangerous situation.
Answer: True False
Explanation:
58) The human body has more sensory input to the CNS than the traditional “five senses.” 58)
Answer: True False
Explanation:
59) When a neuron is resting, it has a higher concentration of Na+ ions inside the cell membrane than 59)
outside.
Answer: True False
Explanation:
60) Any nerve that carries messages from the brain and spinal cord is an afferent division of the PNS. 60)
Answer: True False
Explanation:
61) Neurons are not true cells because they aren’t spherical in shape. 61)
Answer: True False
Explanation:
62) The cilia that respond to sounds in the cochlea have “trapdoor” channels for K+ ions. 62)
Answer: True False

Explanation:

 

 

 

 

 

 

 

 

14

 

MATCHING. Choose the item in column 2 that best matches each item in column 1.

 

Match column 1 with the items in column 2.
63) Cerebrum A) reasoning and memory
Answer: A
Match column 1 with the items in column 2.
64) Afferent neuron A) carries signals away from the CNS
Answer: B B) carries signals to the CNS
  • Efferent neuron Answer: A

 

Match column 1 with the items in column 2.
66) Medulla oblongata A) regulates breathing and blood pressure
Answer: A
Match column 1 with the items in column 2. Answers may be used more than once.
67) Accelerates heart A) sympathetic division
Answer: A
Match column 1 with the items in column 2.
68) Gray matter A) mostly neuron cell bodies
Answer: A
Match column 1 with the items in column 2. Answers may be used more than once.
69) Stimulates skeletal muscles A) somatic division
Answer: A
Match column 1 with the items in column 2.
70) Myelin A) glial membrane wrapping
Answer: A
Match column 1 with the items in column 2. Answers may be used more than once.
71) Constricts pupils A) parasympathetic division
Answer: A
Match column 1 with the items in column 2.
72) Pons A) the “bridge” to the cerebrum
Answer: A
Match column 1 with the items in column 2.
73) Nerve A) bundle of axons
Answer: A
Match column 1 with the items in column 2. Answers may be used more than once.
74) Stimulates salivation A) parasympathetic division
Answer: A

 

 

 

63)

 

 

 

 

64)

 

 

65)

 

 

 

 

66)

 

 

 

 

67)

 

 

 

 

68)

 

 

 

 

69)

 

 

 

 

70)

 

 

 

 

71)

 

 

 

 

72)

 

 

 

 

73)

 

 

 

 

74)

 

 

 

 

 

15

 

Match column 1 with the items in column 2.
75) Hypothalamus A) regulation of drives
Answer: A B) motor control and balance
76) Cerebellum
Answer: B

 

Match column 1 with the items in column 2. Answers may be used more than once.

77) Inhibits digestion                                                            A) sympathetic division

 

Answer: A

 

ESSAY. Write your answer in the space provided or on a separate sheet of paper.

 

  • Why are sensory receptors often called transducers?

 

Answer: They must convert a signal in one form (such as light) into an electrical signal.

75)

 

 

76)

 

 

 

 

77)

 

 

  • Novocain, or procaine, is a chemical that dentists use to numb your mouth before drilling. The chemical blocks the sodium gates on sensory neurons, preventing them from opening. Describe how this chemical decreases (One hopes!) the perception of pain.

 

Answer: Because the chemical prevents sodium gates on the sensory neuron from opening, no sodium enters the neurons. Sodium entering neurons is the signal for nearby channels to open, continuing the spread of sodium influx down the length of the axon. If sodium is blocked from entering voltage-regulated gates, the signal or action potential cannot move down the axon of the sensory neuron; thus, the brain won’t be alerted to the sensation of pain.

 

  • Imagine a person’s spinal cord has been severed high enough that they feel nothing from their legs. Do the sensory neurons in their legs stop functioning? Explain your answer.

 

Answer: The sensory neurons are undamaged and continue functioning. The sensory neurons will still detect stimuli and send an impulse to neurons in the spinal cord. But the pathway running from spinal cord to brain has been cut above the level where the sensory neuron enters, so signals from these neurons won’t be able to reach the brain; therefore, the brain won’t sense anything.

 

  • A person is diagnosed with a brain tumor that is treated with radiation. The treatment is successful, but the doctor believes some brain damage occurred. The patient is constantly complaining of being thirsty, even though she has had plenty of water to drink. Which part of the brain is damaged in this patient and why? Answer: The hypothalamus is a likely candidate because it controls drives such as the thirst drive.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16

 

  • Humans have sophisticated, highly evolved brains that would be useful in directing all body activities. Yet we have the autonomic division and reflexes that intentionally bypass the conscious centers of the brain and directly handle some responses. Evaluate why this is useful. Also, propose situations to the contrary in which it might be useful to use the brain rather than an autonomic response, and explain why we respond as such anyway.

 

Answer: As remarkably fast as the brain works, it still takes time (even if a small amount of time) for a stimulus to pass from one neuron to the next. As small as the synaptic cleft is, it still relies on the relatively slow process of diffusion for the neurotransmitters of one neuron to pass a signal on to the next neuron. Reducing the number of neurons in a chain from stimulus to response may save that half-second or so that could mean the difference between falling and catching our balance. Additionally, there are some situations in which the response to a stimulus is unambiguous, and there is no reason to involve a decision-making process. Some of the simpler aspects of compensating for unbalanced movement to prevent falling or of being able to pull away from a burning object that is doing more damage every fraction of a second we are in contact with it are examples in which decision making in the brain would hardly ever be useful.

 

On the other hand, there are rare situations in which overruling a reflex would be useful, and we are largely powerless to do so. Many people would gladly endure an extra split second of pain in order to place, not drop, that expensive antique vase that has a sharp burr that has cut our hand. Something innocuous that has nonetheless startled us and sent our fight or flight response into overdrive would be preferable to ignore. Yet, in the evolutionary balance sheet, being over-prepared for such responses must have been of greater survival value than not having those reflexes and autonomic responses.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

17

 

 

 

 

 

 

 

 

18

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

19

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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