Sample Chapter

INSTANT DOWNLOAD COMPLETE TEST BANK WITH ANSWERS

 

Test Bank Of Biological Science 4th Edition by Scott Freeman

 

 

SAMPLE QUESTIONS

 

Exam

 

 

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

 

1) Proteins in biological systems _____. 1)
  1. may be high-energy intermediates (for example, ATP)
  2. may be enzymes that catalyze reactions
  3. store genetic information
  4. link together to form the plasma membrane

 

2) The functional groups of amino acids _____. 2)
  1. are identical in different types of amino acids
  2. only contain C, H, and O
  3. are always charged
  4. may be hydrophobic or hydrophilic

 

3) In experiments that successfully simulate chemical evolution, why must at least some small, 3)
reduced molecules be present?
A) They act as proton donors in acid-base reactions.
B) They act as electron acceptors in redox reactions.
C) They act as proton acceptors in acid-base reactions.
D) They act as electron donors in redox reactions.
4) What is the process component of the theory of chemical evolution? 4)
  1. The process occurred at black smokers, in the atmosphere and oceans, and in outer space.
  2. Acid-base reactions resulted in the formation of large, complex organic molecules.
  3. During polymerization reactions, hydrolysis was completed with condensation.
  4. Kinetic energy was transformed into chemical energy.

 

5) What is the pattern component of the theory of chemical evolution? 5)
  1. The process occurred at black smokers, in the atmosphere and oceans, and in outer space.
  2. Both heat and electrical discharges are required for chemical evolution to occur.
  3. Increasingly complex carbon-containing molecules formed early in Earth history.
  4. Most chemical evolution occurred at black smokers.

 

6) Which of the following best describes the first living entity? 6)
A) It was large and extremely complex.
B) It could make a copy of itself.
C) It was a monomer.
7) In interstellar space, millions of ice-encrusted dust particles contain simple carbon-containing 7)
compounds. When particles like these are exposed to solar radiation, more complex organic
molecules form on the surfaces of the dust. What is the significance of these findings?
  1. Chemical evolution occurs only in outer space and was not possible on Earth.
  2. Life began in outer space.
  3. Chemical evolution can occur in outer space.
  4. Life exists in outer space.

 

 

 

 

 

 

 

 

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8) Consider the experiment that Stanley Miller did to simulate chemical evolution. Recall that a glass 8)
flask held the reduced gases NH3, CH4, and H2 and that the gases were exposed to electrical
sparks. What is the null hypothesis in the experiment?
A) Chemical evolution requires the presence of reduced molecules.
B) Chemical evolution requires a source of kinetic energy.
C) Chemical evolution requires continuous heating.
D) Chemical evolution does not occur.
E) Chemical evolution occurs only on Earth.
9) What prediction does the chemical evolution hypothesis make? 9)
  1. Proteins will be produced before any other macromolecule.
  2. Nothing will happen—meaning that no new types of molecules will appear.
  3. A self-replicating macromolecule cannot exist all need interaction with another macromolecule.
  4. Molecules with carbon-carbon bonds will form.

 

10) Suppose that Miller repeated his chemical evolution experiment but without a source of electrical 10)
sparks. What would be the purpose?
  1. to test if electrical energy is required for chemical evolution
  2. to make sure that the glassware had not been contaminated, and that any new molecules found were actually produced by chemical evolution
  3. to test the hypothesis that both reduced molecules and electrical energy are required for chemical evolution

 

  1. to test the hypothesis that reduced molecules are required for chemical evolution

 

11) Which one of the following is not a component of each monomer used to make proteins? 11)
A) a side chain, R B) a phosphorus atom, P
C) an amino functional group, NH2 D) a carboxyl group, COOH
12) What aspects of amino acid structure vary among different amino acids? 12)
  1. the presence of a central C atom
  2. the long carbon-hydrogen tails of the molecule
  3. the components of the R-group
  4. the glycerol molecule that forms the backbone of the amino acid

 

13) Why are polymerization reactions endergonic? 13)
  1. The condensation and hydrolysis reactions are equally spontaneous.
  2. They release heat, making the reactant monomers move faster.
  3. Polymers are energetically more stable and have lower potential energy than monomers do.
  4. They reduce entropy.

 

14) At the pH found in cells (about 7.0), what happens to the amino group on an amino acid? 14)
  1. A) It is reduced, and tends to act as an electron donor in redox reactions.
  2. B) It acts as an acid and loses a proton, giving it a negative charge.
  3. C) It acts as a base and gains a proton, giving it a positive charge.
  4. D) It remains neutral, like water, and does not have a charge.

 

 

 

 

 

 

 

 

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15) At the pH found in cells (about 7.0), what happens to the carboxyl group on an amino acid? 15)
A) It is oxidized, and tends to act as an electron acceptor in redox reactions.
B) It acts as an acid and loses a proton, giving it a negative charge.
C) It remains neutral, like water, and does not have a charge.
D) It acts as a base and gains a proton, giving it a positive charge.
16) How does the structure of an amino acid enable it to play its most important roles in cells? 16)
  1. The presence of carboxyl and amino groups gives it the ability to form peptide bonds, and its side chain gives it unique chemical properties.
  2. It can serve a wide variety of functions in a cell, because it contains the atoms most commonly found in organisms (C, H, N, and O).

 

  1. Because both carboxyl and amino groups are present, polymerization is exergonic. In addition, the presence of a side chain makes the molecule water soluble.

 

  1. Because each amino acid contains a variety of functional groups, they can participate in a wide variety of chemical reactions.

 

17) Which of the following involves an increase in entropy? 17)
A) chemical evolution B) condensation
C) polymerization D) hydrolysis
18) In solution, why do hydrolysis reactions occur more readily than condensation reactions? 18)
  1. Hydrolysis increases entropy and is exergonic.
  2. Hydrolysis increases entropy and is endergonic.
  3. Hydrolysis decreases entropy and is exergonic.
  4. Hydrolysis raises G, or Gibbs free energy.

 

19) Suppose you discovered a new amino acid. Its R-group contains only hydrogen and carbon atoms. 19) Predict the behavior of this amino acid.

 

  1. Relative to the amino acids found in organisms, its interactions with water will be very high.
  2. Relative to the amino acids found in organisms, its interactions with water will be intermediate.
  3. It is hydrophilic.
  4. It is hydrophobic.

 

20) You disrupt all hydrogen bonds in a protein. What level of structure will be preserved? 20)
A) quaternary structure B) primary structure
C) tertiary structure D) secondary structure
21) A peptide bond _____. 21)
  1. forms the primary structure of proteins
  2. forms between the functional groups of different amino acids
  3. forms between the central carbon and the amino group of a single amino acid
  4. does not play a role in maintaining the tertiary structure of proteins

 

22) When polymerization of a protein is complete, but the protein is still completely linear, what is the 22)
highest level of structure that has been completed?
A) tertiary B) quaternary C) primary D) secondary

 

 

 

 

 

 

 

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23) You determine the amino acid sequence of a protein and find it contains a long sequence of 23)
methionine, followed by a long sequence of proline, followed by a long sequence of valine. Using
these data you predict the sequence of this protein’s secondary structure will be _____.
A) beta sheets, then a region of no secondary structure, then beta sheets
B) beta sheets, then a region of no secondary structure, then alpha helices
C) alpha helices, then a region of no secondary structure, then beta sheets
D) alpha helices, then a region of no secondary structure, then alpha helices
24) You are studying a protein that is shaped like a doughnut. The shape is a function of which level(s) 24)
of protein structure?
  1. primary, secondary, and tertiary
  2. tertiary only
  3. secondary only
  4. secondary and tertiary only
  5. primary only

 

25) An enzyme has a total of four active sites. When you denature the molecule and study its 25)
composition, you find that each active site occurs on a different polypeptide. Which of the
following hypotheses does this observation support?
A) The enzyme requires a cofactor to function normally.
B) The protein’s structure is affected by temperature and pH.
C) The enzyme is subject to allosteric regulation.
D) The protein has quaternary structure.
26) Which of the following observations is the strongest argument in favor of the hypothesis that 26)
protein structure and function are correlated?
  1. Proteins have four distinct levels of structure and many functions.
  2. Denatured (unfolded) proteins do not function normally.
  3. Enzymes tend to be globular in shape.
  4. Proteins function best at certain temperatures.

 

27) You’ve just sequenced a new protein found in mice and observe that sulfur-containing cysteine 27)
residues occur at regular intervals. What is the significance of this finding?
  1. Cysteine residues are involved in disulfide bridges that help form tertiary structure.
  2. Cysteine residues are required for the formation of -helices and  -pleated sheets.
  3. Cysteine causes bends, or angles, to occur in the tertiary structure of proteins.
  4. It will be important to include cysteine in the diet of the mice.

 

28) Aquaporins are proteins that control the passage of water molecules across the cell membrane. The 28) protein forms a pore, or opening, in the membrane. You isolate what you think are two different molecules of aquaporin, and determine that one of the proteins has a larger pore diameter than the second. Which of the following do you conclude?

 

  1. These two forms of aquaporin will have identical sequences of amino acids.
  2. These molecules both can’t have aquaporin because all proteins that do the same type of job (such as catalyze a reaction) have the exact same 3-D structure.
  3. You will have to sequence the proteins to compare their primary structure, because it should have no effect on pore diameter.

 

  1. These two forms of aquaporin will have different sequences of amino acids.

 

 

 

 

 

 

 

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29) What type of interaction is directly responsible for the formation of secondary structure? 29)
A) hydrogen bonds between sections of the polypeptide backbone
B) peptide bonds between nonadjacent amino acids
C) hydrogen bonds between side chains of amino acids
D) peptide bonds between adjacent amino acids
30) A series of hydrophobic side chains will congregate together as a protein folds in an aqueous 30)
solution and be stabilized by _____.
A) quaternary structure bonds B) van der Waals interaction
C) disulfide bonds D) hydrogen bonds
31) How does primary protein structure affect the function of protein enzymes? 31)
  1. Substrates interact with hydrophobic R-groups at any region of the enzyme.
  2. Substrates interact with R-groups at the enzyme’s external surface.
  3. Substrates interact with R-groups at the enzyme’s active site.
  4. Substrates permanently bind to R-groups at the enzyme’s active site.

 

32) You have isolated a previously unstudied protein, identified its complete structure in detail, and 32)
determined that it catalyzes the breakdown of a large substrate. You notice it has two binding sites.
One of these is large, apparently the bonding site for the large substrate; the other is small, possibly
a binding site for a regulatory molecule. What do these findings tell you about the mechanism of
this protein?
A) It is probably a structural protein that is involved in cell-to-cell adhesion.
B) It is probably an enzyme that works through allosteric regulation.
C) It is probably a cell membrane transport protein—like an ion channel.
D) It is probably an enzyme that works through competitive inhibition.
E) It is probably a structural protein found in cartilage or skeletal tissue.
33) Which of the following is true when comparing an uncatalyzed reaction to the same reaction with 33)
a catalyst?
A) The catalyzed reaction will have higher activation energy.
B) The catalyzed reaction will have the same  G.
C) The catalyzed reaction will be slower.
D) The catalyzed reaction will consume all of the catalyst.
34) Which of the following would be an example of a cofactor? 34)
A) a  -pleated sheet hidden on the inside of a protein’s tertiary structure
B) the disulfide bridge that forms between cysteine residues
C) an enzyme active site that contains an  -helix
D) the nonprotein heme group in a hemoglobin molecule
35) In cells, the activity of enzymes is often regulated by other molecules. Why is this necessary? 35)
  1. because each enzyme has multiple functions
  2. because it is unlikely that all reaction products are required all of the time
  3. because other molecules are necessary to prevent enzymes from denaturing
  4. because all enzymes require some help from another molecule to function correctly

 

 

 

 

 

 

 

 

 

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36) Several of the molecules called vitamins act as enzyme cofactors. Vitamin deficiencies cause 36)
disease. What is the most direct explanation for this?
  1. Vitamins combine with nonprotein molecules to delay the onset of disease.
  2. Cofactors inhibit enzymes found in disease-causing bacteria and viruses. When cofactors are absent, these disease-causing agents multiply.
  3. Normal regulation cannot occur in the absence of cofactors. As a result, all enzymes will function all of the time.

 

  1. If cofactors are missing, enzymes cannot function properly, and important reaction products will be absent from cells.

 

37) You’ve discovered an enzyme that can catalyze two different chemical reactions. Which of the 37)
following is most likely to be correct?
  1. The enzyme is subject to both competitive inhibition and allosteric regulation.
  2. The enzyme contains both -helices and  -pleated sheets.
  3. Two types of allosteric regulation occur: The binding of one molecule activates the enzyme, while the binding of a different molecule inhibits it.
  4. Either the enzyme has two distinct active sites, or the reactants involved in the two reactions are very similar in size and shape.

 

38) HIV is the virus that causes AIDS. In the mid-1990s, researchers discovered an enzyme in HIV 38)
called protease. Once the enzyme’s structure was known, researchers began looking for drugs that
would fit into the active site and block it. If this strategy for stopping HIV infections were
successful, it would be an example of what phenomenon?
A) allosteric regulation B) competitive inhibition
C) poisoning D) vaccination
39) Consider the HIV enzyme called protease. The amino acid residues at the active site are highly 39)
hydrophobic. In designing a drug that would bind to the active site and jam it, researchers should
use which type of molecule?
A) polar B) hydrophobic C) acidic D) charged
40) The lock-and-key analogy for enzymes applies to the _____. 40)
  1. specificity of enzymes interacting with ions
  2. specificity of enzymes binding to their substrate
  3. specificity of enzymes interacting with water
  4. specificity of enzyme tertiary subunits joining to form a quaternary structure
  5. specificity of enzyme primary, secondary, and tertiary structure

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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41) You collect data on the effect of pH on the function of the enzyme catalase in human cells. Which 41)
of the following graphs would you expect?
A) B)

 

 

 

 

 

 

 

 

  1. C) D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

Refer to the following paragraph and Figure 3.1 to answer the following questions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3.1

 

Since structure correlates so well with function, biochemists are constantly looking for new ways to probe the complex structure of proteins in order to understand what they do and how they do it. One of the most powerful techniques in existence today is X-ray crystallography. The main difficulty with this technique is getting the protein to crystallize. Once crystallized, the protein is bombarded with X-rays to create a pattern that can be analyzed mathematically to determine the three-dimensional structure of the protein. This analysis has been performed by Krzysztof Palczewski on the protein rhodopsin, which is a light-sensitive protein found in species ranging from ancient bacteria (archaea) to humans. The structure (schematically shown above, where each letter represents an amino acid) is characterized by a single polypeptide chain with several -helical segments that loop back and forth across the cell membrane. Another notable feature is the disulfide bond (-S-S-) that can be seen at the bottom of the third transmembrane segment. [Figure adapted from K. Palczewski et al., Science 289 (2000): 739.]

 

42) How many times does the protein in Figure 3.1 cross the cell membrane? 42)
A) 1 B) 3 C) 4 D) 7
43) If you were reading off the sequence of amino acids in Figure 3.1 to a biologist friend, what should 43)
the first three letters be?
  1. M-N-G
  2. A-P-A
  3. It doesn’t matter, since the protein has no polarity or directionality.

 

44) Identify the location of the disulfide bond in Figure 3.1. What is the name of the amino acids that 44)
are forming this bond?
A) cytosine B) aspartic acid C) glycine D) cysteine

 

 

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45) What is the location of the C-terminus of the protein in Figure 3.1? 45)
A) nucleus B) extracellular
C) embedded within the membrane D) cytoplasm
46) Refer to Figure 3.1. Which level of structure is being maintained by the disulfide bond? 46)
A) primary B) secondary C) quaternary D) tertiary
47) Which term best describes the type of membrane protein in Figure 3.1? 47)
A) internal B) peripheral C) external D) integral

 

 

Exam

 

 

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

 

1) Mendel crossed yellow-seeded and green-seeded pea plants and then allowed the offspring to 1)
self-pollinate to produce an F2 generation. The results were as follows: 6022 yellow and 2001 green
(8023 total). The allele for green seeds has what relationship to the allele for yellow seeds?
A) dominant B) recessive
C) incomplete dominant D) codominant
2) A man and woman are both of normal pigmentation, but both have one parent who is albino 2)
(without melanin pigmentation). Albinism is an autosomal (not sex-linked) recessive trait. What is
the probability that their first child will be an albino?
A) 0 B) 1/8 C) 1/2 D) 1/4 E) 1
3) A man and woman are both of normal pigmentation, but both have one parent who is albino 3)
(without melanin pigmentation). Albinism is an autosomal (not sex-linked) recessive trait. What is
the probability that their first female child will have albinism?
A) 0 B) 1/8 C) 1/2 D) 1/4 E) 1
4) A man and woman are both of normal pigmentation and have a one child out of three who is 4)
albino (without melanin pigmentation). Albinism is an autosomal (not sex-linked) recessive trait.
What are the genotypes of the albino’s parents?
  1. Both parents must be heterozygous.
  2. Both parents must be homozygous dominant.
  3. One parent must be homozygous dominant; the other parent must be heterozygous.
  4. One parent must be heterozygous; the other parent can be homozygous dominant, homozygous recessive, or heterozygous.
  5. One parent must be homozygous for the recessive allele; the other parent can be homozygous dominant, homozygous recessive, or heterozygous.

 

5) In tigers, a recessive allele causes a white tiger (absence of fur pigmentation). If one phenotypically 5)
normal tiger that is heterozygous is mated to another that is phenotypically white, what percentage
of their offspring is expected to be white?
A) 50% B) 0% C) 75% D) 25% E) 100%
6) A man has extra digits (six fingers on each hand and six toes on each foot). His wife and their 6)
daughter have a normal number of digits. Having extra digits is a dominant trait. The couple’s
second child has extra digits. What is the probability that their next (third) child will have extra
digits?
A) 1/2 B) 1/8 C) 3/4 D) 1/16 E) 9/16
7) Different ratios occur in crosses with single gene pairs or two gene pairs. What types of ratios are 7)

likely to occur in crosses dealing with a single gene pair?

  1. A) 3:1, 1:1, 1:2:1 B) 9:3:3:1, 1:2:1 C) 4:1, 1:1, 1:4:1                    D) 1:1:1:1, 1:4:6:4:1

 

 

 

 

 

 

 

 

 

 

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8) A black guinea pig crossed with an albino guinea pig produced 12 black offspring. When the albino 8) was crossed with a second black animal, 6 blacks and 6 albinos were obtained. What is the best explanation for this genetic situation?

 

  1. Albino is recessive; black is codominant.
  2. Albino and black are codominant.
  3. Albino is dominant; black is incompletely dominant.
  4. Albino is recessive; black is dominant.

 

9) Gray seed color in peas is dominant to white. Assume that Mendel conducted a series of 9)
experiments where plants with gray seeds were crossed among themselves, and the following
progeny were produced: 302 gray and 98 white. (a) What is the most probable genotype of each
parent? (b) Based on your answer in (a) above, what genotypic and phenotypic ratios are expected
in these progeny? (Assume the following symbols: G = gray and g = white.)
A) (a) GG × gg; (b) genotypic = 3:1, phenotypic = 1:2:1
B) (a) gg × Gg; (b) genotypic = 1:2, phenotypic = 3:1
C) (a) GG × Gg; (b) genotypic = 1:2:1, phenotypic = 2:1
D) (a) Gg × Gg; (b) genotypic = 3:1, phenotypic = 9:3:3:1
E) (a) Gg × Gg; (b) genotypic = 1:2:1, phenotypic = 3:1
10) Phenylketonuria is an inherited disease caused by a recessive autosomal allele. If a woman and her 10)
husband are both carriers, what is the probability that their first child will be a phenotypically
normal girl?
A) 3/16 B) 1.0 C) 1/16 D) 1/4 E) 3/8
11) Assuming independent assortment for all gene pairs, what is the probability that the following 11)
parents, AABbCc × AaBbCc, will produce an AaBbCc offspring?
A) 3/4 B) 1/16 C) 1/2 D) 9/16 E) 1/8
12) Suppose two AaBbCc individuals are mated. Assuming that the genes are not linked, what fraction 12)
of the offspring are expected to be homozygous recessive for the three traits?
A) 1/16 B) 1/8 C) 1/64 D) 1/256 E) 1/4
13) When Mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow 13)
seeded. When he took these F1 yellow-seeded plants and crossed them to green-seeded plants,
what genotypic ratio is expected?
A) 1:2:1 B) 1:1:1:1 C) 9:3:3:1 D) 1:1 E) 3:1
14) In rabbits, the homozygous CC is normal, Cc results in deformed legs, and cc results in very short 14)
legs. The genotype BB produces black fur, Bb brown fur, and bb white fur. If a cross is made
between brown rabbits with deformed legs and white rabbits with deformed legs, what percentage
of the offspring would be expected to have deformed legs and white fur?
A) 33% B) 50% C) 100% D) 25% E) about 66%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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15) In Drosophila melanogaster, vestigial (short) wings (vg) are caused by a recessive allele of a gene that 15)

independently assorts with a gene pair that influences body hair. Hairy (h) results in a hairy body. A cross is made between a fly with normal (wild) wings and a hairy body and a fly with vestigial wings and a normal (wild) body. The phenotypically normal F1 flies were crossed among each other, and 1024 F2 flies were reared. What phenotypes would you expect in the F2, and in what actual numbers (not ratios) would you expect to find them?

  1. phenotypes wild, vestigial; numbers expected  wild (576), vestigial (576)
  2. phenotypes hairy, vestigial hairy; numbers expected  hairy (512), vestigial hairy (512)
  3. phenotypes wild, vestigial, hairy, vestigial hairy; numbers expected wild (256), vestigial (256), hairy (256), vestigial hairy (256)
  4. phenotypes all wild; numbers expected  wild (1024)
  5. phenotypes wild, vestigial, hairy, vestigial hairy; numbers expected wild (576), vestigial (192), hairy (192), vestigial hairy (64)

 

16) A heterozygous, but phenotypically wild-type fruit fly (gray body color and normal wings) was 16)
mated to a black fly with vestigial wings. The offspring had the following phenotypic distribution:
wild type, 720; black-vestigial, 780; black-normal, 280; gray-vestigial, 220. What conclusion is
likely from these results?
A) The black and vestigial loci assort independently from each other.
B) The black and vestigial loci are allelic.
C) The black and vestigial loci are linked.
D) Epistasis has modified a 9:3:3:1 ratio.
17) Pseudohypertrophic muscular dystrophy is a human disorder that causes gradual deterioration of 17)
the muscles. Only boys are affected, and they are always born to phenotypically normal parents.
Due to the severity of the disease, the boys die in their teens. Is this disorder likely to be caused by a
dominant or recessive allele? Is its inheritance sex-linked or autosomal?
A) recessive, sex-linked B) recessive, autosomal
C) dominant, sex-linked D) incomplete dominant, sex-linked
18) In birds, sex is determined by a ZW chromosome scheme that is much like the typical XY scheme 18)
seen in humans and many other organisms, except that the system is reversed: Males are ZZ
(similar to XX in humans) and females are ZW (similar to XY in humans). A lethal recessive allele
that causes death of the embryo occurs on the Z chromosome in pigeons. What would be the sex
ratio in the offspring of a cross between a male heterozygous for the lethal allele and a normal
female?
A) 2:1 male to female
B) 1:2 male to female
C) 3:1 male to female
D) 1:1 male to female
E) 4:1 male to female
19) A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A 19)
woman with normal vision whose father is color blind marries a color-blind male. What is the
probability that this couple’s first son will be color blind?
A) about 33% B) about 66% C) 75% D) 50% E) 25%
20) Hemophilia is caused by several genetic factors; one, a recessive allele of an X-linked gene, is the 20)
subject of this problem. Assume that a man with hemophilia marries a normal woman whose
father had hemophilia. What is the probability that they will have a daughter with hemophilia?
A) 1/4 B) 3/4 C) 1/16 D) 1/2 E) 1/8

 

 

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21) Hemophilia is caused by several genetic factors; one, a recessive allele of an X-linked gene, is the 21)
subject of this problem. Assume that a man with hemophilia marries a normal woman whose
father had hemophilia. What is the probability that their first son will have hemophilia?
A) 1/2 B) 1/16 C) 1/8 D) 3/4 E) 1/4
22) A man who carries an allele of an X-linked gene will pass it on to _____. 22)
  1. all of his daughters
  2. half of his sons
  3. all of his children
  4. half of his daughters
  5. all of his sons

 

23) Glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as a recessive allele of an 23)

X-linked gene in humans. A woman whose father suffered from G6PD marries a normal man. (a)

What proportion of their sons is expected to be G6PD? (b) If the husband was not normal but was

G6PD deficient, would you change your answer in part (a)?

  1. A) (a) zero; (b) no
  2. B) (a) 1/2; (b) yes
  3. C) (a) 1/2; (b) no
  4. D) (a) 100%; (b) no
  5. E) (a) 2/3; (b) no

 

 

 

 

 

 

 

 

Figure 13.1

 

24) In a Drosophila experiment, a cross was made between homozygous wild-type females and 24)

yellow-bodied males. All of the resulting F1s were phenotypically wild type. However, adult flies of the F2 generation (resulting from matings of the F1s) had the characteristics shown in the figure above:

 

  • Is the mutant allele for yellow body recessive or dominant?
  • Is the yellow locus autosomal (not X-linked) or X-linked?
A) (a) recessive; (b) not X-linked B) (a) dominant; (b) X-linked
C) (a) recessive; (b) X-linked D) (a) dominant; (b) not X-linked
25) A homozygous tomato plant with red fruit and yellow flowers was crossed with a homozygous 25)
tomato plant with golden fruit and white flowers. The F1 all had red fruit and yellow flowers. The
following phenotypes were obtained in the F2:
Red fruit and yellow flowers—41
Red fruit and white flowers—7
Golden fruit and yellow flowers—8
Golden fruit and white flowers—44
How many map units separate these genes?
A) 18.1 B) 35 C) 15 D) 17.6 E) 17.1

 

 

 

 

 

4

 

26) In humans, blue eyes are inherited as a recessive autosomal trait and color blindness is an X-linked 26) recessive trait. A woman with blue eyes and normal color vision whose father was color blind

 

marries a man who also has normal color vision. He has brown eyes, but his mother had blue eyes. Which of the following do you expect to be true for their sons?

 

  1. One-fourth of their sons will be color blind and have blue eyes, 1/4 of their sons will be color blind and have brown eyes, 1/4 of their sons will have normal color vision and blue eyes, 1/4 of their sons will have normal color vision and brown eyes.

 

  1. Their sons will all have normal color vision and blue eyes.
  2. One-half of their sons will have normal color vision and brown eyes; 1/2 of their sons will have normal color vision and blue eyes.
  3. Their sons will all have normal color vision and brown eyes.
  4. One-half of their sons will be color blind and have blue eyes; 1/2 their sons will be color blind and have brown eyes.

 

27) In humans, blue eyes are inherited as a recessive autosomal trait and color blindness is an X-linked 27) recessive trait. A woman with blue eyes and normal color vision whose father was color blind

 

marries a man who also has normal color vision. He has brown eyes but his mother had blue eyes. Which of the following do you expect to be true for their daughters?

 

  1. One-fourth of their daughters will be color blind and have blue eyes, 1/4 of their daughters will be color blind and have brown eyes, 1/4 of their daughters will have normal color vision and blue eyes, 1/4 of their daughters will have normal color vision and brown eyes.

 

  1. One-half of their daughters will be color blind and have blue eyes; 1/2 their daughters will be color blind and have brown eyes.

 

  1. One-half of their daughters will have normal color vision and brown eyes; 1/2 of their daughters will have normal color vision and blue eyes.

 

  1. Their daughters will all have normal color vision and have blue eyes.
  2. Their daughters will all have normal color vision and brown eyes.

 

28) In Drosophila melanogaster, vestigial wings are caused by a recessive allele of a gene that is linked to 28)

a gene with a recessive allele that causes black body color. Morgan crossed black-bodied normal-winged females and gray-bodied vestigial-winged males. The F1 were all gray bodied, normal winged. After examining the F2 progeny, Morgan calculated the map distance to be 17 map units. Which of the following is correct about the F2 progeny?

  1. black-bodied, vestigial-winged flies = 17%
  2. black-bodied normal-winged flies = 17%
  3. black-bodied, normal-winged flies PLUS gray-bodied, vestigial-winged flies = 17%
  4. gray-bodied, normal-winged flies PLUS black-bodied, vestigial-winged flies = 17%

 

29) Regarding an allelic pair for flower color in snapdragons, heterozygotes have pink flowers, 29)
whereas the two homozygotes have red flowers or white flowers. When plants with red flowers are
crossed with plants with white flowers, what proportion of the offspring is expected to have pink
flowers?
A) 100% B) 50% C) 0% D) 75% E) 25%

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

30) Snapdragons are flowers that come in a variety of colors, including red, pink, and white. A series of     30)

crosses with snapdragons having flowers of different colors produced the following results:

pink × pink: 27 pink, 13 red, 14 white

red × red: all red

white × white: all white

pink × white: 29 pink, 26 white

pink × red: 28 pink, 27 red

white × red: all pink

 

Based on the results, what is the most reasonable explanation for the inheritance of these flower colors?

  1. qualitative effects
  2. codominance
  3. pleiotropic effects
  4. incomplete dominance
  5. more than two alleles

 

31) Whenever the dominant allele of either (or both) gene A or gene B is present, red color is produced. 31)
A cross of AaBb × AaBb can be expected to yield how many red offspring out of 16? Assume the
genes are not linked.
A) 1 B) 4 C) 12 D) 15 E) 16
32) In humans, ABO blood types refer to glyocproteins in the membranes of red blood cells. There are 32)

three alleles for this autosomal gene: IA, IB, and i. The IA allele codes for the A glycoprotein, The IB allele codes for the B glycoprotein, and the i allele doesn’t code for any membrane glycoprotein. IA and IB are codominant, and i is recessive to both IA and IB. People with A type blood have the genotypes IAIA or IAi, people with type B blood are IBIB or IBi, people with type AB blood are IAIB, and people with O type blood are ii. If a woman with type AB blood marries a man with type O blood, which of the following blood types could their children possibly have?

  1. A and B
  2. AB and O
  3. A, B, and O
  4. A, B, and AB
  5. A, B, AB, and O

 

 

Exam

 

 

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

 

1) Most coal was formed during the Carboniferous period. What is a reasonable hypothesis that 1)

explains this observation?

  1. A) There were not many mycorrhizal fungi during this period.
  2. B) Plants from this period did not require fungal associations.
  3. C) There were not many saprophytic fungi during this period.
  4. D) Coal was formed from an explosion of fungal species during this period.

 

2) There was a mass extinction of plants and animals at the end of the Permian period 250 million 2)
years ago. Which of the following would be a reasonable prediction for the fungal fossil record?
  1. There should be a massive decrease in all fungal fossils just prior to the time that plant and animal species started to decline, and the number of these fossils should remain low throughout the extinction period.

 

  1. There should be a massive increase in saprophytic fossils during the extinction, and then a massive decline shortly after the extinction was complete.

 

  1. There should be a slow increase in all fungal fossils during the time that plant and animal species declined, with their numbers staying relatively high afterward since there was little competition from other species.

 

  1. There should be a massive increase in mycorrhizal fossils during the extinction and few afterward.

 

3) Which of the following is an important role for fungi in the carbon cycle? 3)
  1. Fungi get involved in the fixation of carbon by undergoing photosynthesis.
  2. Fungi help release fixed carbon back to the environment for other plants and photosynthetic organisms to utilize.
  3. One of fungi’s main roles is to provide already fixed carbon to plants that the plants then use for the production of cellular tissues.

 

  1. Fungi reduce atmospheric carbon dioxide.

 

4) You want to run an experiment to determine if an organism is a fungus. You place the organism in 4)
a petri dish with a small piece of wood. Which of the following results would support your
hypothesis that your unknown organism is indeed a fungus?
A) The presence of mold on the wood.
B) The presence of lignin in the dish.
C) The presence of cellulose in the dish.
D) The presence of decomposing bacteria in the dish.
E) The presence of glucose in the dish.
5) Fungi that absorb nutrients from decaying plant matter are called _____. 5)
A) mycorrhizae
B) yeasts
C) mushrooms
  1. D) saprobes
  2. E) molds

 

 

 

 

 

 

 

 

1

 

6) You decide to bake bread from scratch. Which of the following is required to make your dough 6)
rise?
A) a mycorrhizal fungus
B) a multicellular fungus
C) a mutualistic fungus
D) Saccharomyces cerevisiae
E) a saprophytic fungus
7) Fungi have an extremely high surface-area-to-volume ratio. What is the advantage of this to an 7)
organism that gets most of its nutrition through absorption?
  1. This high ratio means that fungi have a thick, fleshy structure that allows the fungi to store more of the food it absorbs.

 

  1. The larger surface area allows for more material to be transported through the cell membrane.
  2. The lower volume prevents the cells from drying out too quickly, which can interfere with absorption.
  3. This high ratio creates more room inside the cells for additional organelles involved in absorption.

 

8) You are a forester charged with increasing productivity in a South American forest newly planted 8)

with pines from Oregon. You believe that the southern forest lacks the fungal diversity needed by the North American pines, and that this lack of fungi is affecting the pines’ productivity, but you have no evidence to support your ideas. To count how many fungal species were present in the Oregon forest, which methodology would you choose?

  1. Do direct sequencing on representative soil samples from across the forest.
  2. Count all the plant species and multiply by six, as David Hawksworth did when determining the ratio of fungal to plant species in England.
  3. Collect all the fruiting structures (mushrooms, morels, etc.) found above ground.
  4. Expose the trees to radiolabeled CO2 and then collect the soil samples with the greatest radioactivity and do direct sequencing.

 

9) Why is it more difficult to treat fungal infections than bacterial infections in humans? 9)
  1. Fungal and animal cells and proteins are similar. Thus, drugs that disrupt fungal cell or protein function may also disrupt human cell or protein function.
  2. Fungi are able to mutate more quickly than bacteria, so they quickly develop resistance to antifungal drugs.

 

  1. Fungi are larger organisms than bacteria and thus require stronger drugs to stop an infection.
  2. Most fungi are multicellular and thus the drugs required to treat a fungal infection must be able to kill several types of cells; bacteria, on the other hand, are unicellular and thus simpler to kill.

 

10) It has been hypothesized that fungi and plants have a mutualistic relationship because fungi 10)
provide critical nitrogen for the plants’ use. How do we know this happens?
  1. Plants acquire more radioactive nitrogen when they are associated with fungi.
  2. When plants are associated with fungi, they can fix atmospheric nitrogen that has been tagged with a radioactive label.
  3. Radioactively labeled sugars in plants eventually find their way to their symbiotic fungi.
  4. Radioactively labeled nitrogen shows up in fungi when they are symbiotic with plants.

 

 

 

 

 

 

 

 

2

 

11) It has been hypothesized that fungi and plants have a mutualistic relationship because plants make 11) sugars available for the fungi’s use. What is the best evidence in support of this hypothesis?

 

  1. Radioactive label experiments show that plants pass crucial raw materials to the fungus for manufacturing sugars.

 

  1. Fungi associated with plants have the ability to undergo photosynthesis and produce their own sugars, while those not associated with plants do not produce their own sugars.

 

  1. Radioactively labeled sugars produced by plants eventually show up in the fungi they are associated with.

 

  1. Fungi survive better when they are associated with plants.

 

12) You observe the gametes of a fungal species under the microscope and realize that they resemble 12)
animal sperm. To which of the following group does the fungus belong?
A) Zygomycetes
B) Basidiomycota
C) Chytrids
D) Microsporidia
E) Ascomycota
13) Predict what you would see if you were looking at a new species of Zygomycetes. 13)
A) flagellated spores
B) its ability to form an association with plant roots
C) susceptibility to fungicide
D) a zygote enclosed in a tough outer coat
E) multicellularity
14) Which of these fungal features supports the phylogenetic conclusion that fungi are more closely 14)
related to animals than plants?
A) Fungi are able to change their body shape continuously throughout their life.
B) Zygomycetes have flagellated gametes.
C) The cell walls of fungi are made of chitin.
D) Fungi store polysaccharides as starch.
15) Why are mycorrhizal fungi superior to plants at acquiring mineral nutrition from the soil? 15)
  1. Fungi secrete extracellular enzymes that can break down large molecules.
  2. Hyphae are 100 to 1000 times larger than plant roots.
  3. Mycelia are able to grow in the direction of food.
  4. Hyphae have a smaller surface-area-to-volume ratio than do the hairs on a plant root.

 

16) Long, branching fungal filaments are called _____. 16)
A) mycelia B) ascus C) hyphae D) septa E) roots
17) A cell has two haploid nuclei. This means it is _____. 17)
A) dikaryotic B) a zygote C) yeast D) haploid E) diploid

 

 

 

 

 

 

 

 

 

 

 

 

 

3

 

18) Basidiomycetes are the only fungal group capable of synthesizing lignin peroxidase. What 18)
advantage does this group of fungi have over other fungi because of this capability?
  1. This fungal group can break down the tough lignin, which cannot be harnessed for energy, to get to the more useful cellulose.

 

  1. This is always the first group of fungi to begin any kind of plant decomposition.
  2. This enzyme releases heat energy from the breakdown of lignin that is used to kill off competing fungi.
  3. This is the only group of fungi that can use lignin for ATP production.

 

19) Why is it important that ectomycorrhizal fungi (EMF) have peptidase enzymes? 19)
  1. These enzymes are needed to release nitrogen from dead plant material in colder environments.
  2. These enzymes assist with the breakdown of cellulose.
  3. These enzymes are necessary to break through the tough lignin layers in plants.
  4. These enzymes catalyze the formation of the compounds used during decomposition.

 

20) This group of fungi has the ability to penetrate its host’s cell wall, thus increasing the efficiency 20)
with which materials are passed from fungus to host.
A) lichens B) endophytes
C) ectomycorrhizal fungi D) arbuscular mycorrhizal fungi
21) Which fungal class is not matched with its most common habitat? 21)
A) AMF   tropics B) AMF   grasslands
C) EMF    warm climate forests D) EMF    northern coniferous forests
22) Some fungal species can kill herbivores while feeding off of sugars from its plant host. What type of 22)
relationship does this fungus have with its host?
A) parasitic B) predatory C) commensal D) mutualistic

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

 

Use the following information when answering the corresponding question(s).

 

Suzanne Simard and colleagues knew that the same mycorrhizal fungal species could colonize multiple types of trees. They wondered if the same fungal individual would colonize different trees, forming an underground network that potentially could transport carbon and nutrients from one tree to another (S. Simard et al. 1997. Net transfer of carbon between mycorrhizal tree species in the field. Nature 388:579–82). Figure 31.2 illustrates the team’s experimental setup. Pots containing seedlings of three different tree species were set up and grown under natural conditions for three years; two of the three species formed ectomycorrhizae (Douglas fir, birch) and the other (cedar) formed arbuscular mycorrhizae. For the experiment, the researchers placed airtight bags over the Douglas fir and birch seedlings; into each bag, they injected either carbon dioxide made from carbon-13 or carbon-14 (13CO2 and 14CO2, isotopes of carbon). As the seedlings photosynthesized, the radioactive carbon dioxide was converted into radioactively labeled sugars that could be tracked and measured by the researchers.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 31.2                                                                                           Figure 31.3

 

23) Refer to Figure 31.2. Which of the following results would support Simard et al.’s (1997) hypothesis 23) that fungi can move carbon from one plant to another? Hypothesis: Sugars made by one plant

 

during photosynthesis can travel through a mycorrhizal fungus and be incorporated into the tissues of another plant.

  1. Carbon-14 is found in the Douglas fir seedling’s tissues and carbon-13 in the birch.
  2. Carbon-14 is found in the birch seedling’s tissues and carbon-13 in the Douglas fir.
  3. Either carbon-13 or carbon-14 is found in the fungal tissues.
  4. Either carbon-13 or carbon-14 is found in the cedar seedling’s tissues.

 

 

 

 

 

 

 

 

 

 

 

 

 

5

 

24) Referring to Simard et al. (1997), what is the result that would most strongly refute their 24)
hypothesis?
  1. Either carbon-13 or carbon-14 is found in the fungal tissues.
  2. Either carbon-13 or carbon-14 is found in the cedar seedling’s tissues.
  3. Reciprocal exchange: Carbon-14 is found in the Douglas fir seedling’s tissues and carbon-13 in the birch.
  4. No movement: Carbon-14 is found in the birch seedling’s tissues and carbon-13 in the Douglas fir.

 

25) Referring to Simard et al. (1997), which design element is the control in this experiment and why? 25)
A) the fact that all the seedlings are different species
B) the bags over the seedlings to contain the different types of carbon dioxide
C) the cedar seedling, because it forms arbuscular mycorrhizae
D) the cedar seedling, because it is not bagged
26) Simard et al. (1997) further hypothesized that if reciprocal transfer did occur, it would be a 26)
source-sink relationship driven by photosynthetic rates. That is, if one seedling is in full Sun and
the other in deep shade, there will be a net movement of carbon from the seedling in full Sun to the
one in deep shade. If a shade was placed over the birch seedlings and the cedar, and the Douglas fir
was left in full Sun, what result could Simard and colleagues expect?
A) The most 14C would be found in the cedar.
B) More 13C would be found in the Douglas fir than in the birch.
C) More 13C would be found in the birch than in the Douglas fir.
D) The most 13C would be found in the cedar.
27) At which stage of a basidiomycete’s life cycle would reproduction be halted if an enzyme that 27)
prevented the fusion of hyphae was introduced?
A) plasmogamy
B) fertilization
C) karyogamy
D) germination
E) meiosis
28) Microsporidians are considered parasitic because of the ability to penetrate their host cells using 28)
this structure.
A) mycelium B) chitin C) sporangia D) polar tube
29) The fungus used to produce penicillin and other antibiotics belongs to which fungal lineage? 29)
  1. Chytridiomycota
  2. Ascomycota
  3. Glomeromycota
  4. Zygomycota
  5. Basidiomycota

 

 

 

 

 

 

 

 

 

 

 

 

6

 

30) Many amphibian populations have been decimated by a parasitic fungi belonging to which 30)
lineage?
A) Glomeromycota
B) Chytridiomycota
C) Ascomycota
D) Basidiomycota
E) Zygomycota
31) Based on the idea that fungi have pores between their cell walls, which allow cytoplasm to move 31)
from one end of the mycelium to the other, which of the following hypotheses is the most
plausible?
  1. Predatory fungi capture their prey by encircling them with hyphae, and the flowing of the cytoplasm through the pores helps the hyphae to move around the prey.

 

  1. If a single mycorrhizal fungus formed symbiotic associations with more than one tree, carbon could travel from one plant to another.

 

  1. Parasitic fungi steal nutrients from their hosts.
  2. Fungi function as part of the global carbon cycle not only by converting carbon from one form to another, but by physically moving it from one location to another.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

 

Use the following information when answering the corresponding question(s).

 

There is much discussion in the media about protecting biodiversity, but does it really matter? Canadian and Swiss researchers wanted to know if the diversity of arbuscular mycorrhizal fungi (AMF) was important to the productivity of grasslands (M.G.A. van der Heijden, J. N. Klironomos, M. Ursic, P. Moutoglis, R. Streitwolf-Engel, T. Boler, A. Wiemken, and I. R. Sanders. 1998. Mycorrhizal fungal diversity determines plant biodiversity, ecosystem variability and productivity. Nature 396:69–72). Specifically, they wanted to know if it mattered which specific AMF species were present, or just that some type of AMF was present. They grew various plants in combination with one of four AMF species, no AMF, or all four AMF species together; and they measured plant growth under each set of conditions. All plant species were grown in each plot, so they always competed with each other with the only difference being which AMF species were present. Use the graphs in Figure 31.4 to answer the questions that follow. Note that the x-axis labels indicate the number and identity of AMF species (bar 0 = no fungi; bars A–D = individual AMF species; bar A+B+C+D = all AMF species together). The y-axis indicates the amount (grams) of plant biomass for the species shown in italics above each graph.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 31.4
32) Based on the graphs in Figure 31.4, which of the following plant species is most likely not to form 32)
mycorrhizal associations?
A) Carex flacca (graph a) B) Lotus corniculatus (graph b)
C) Sanguisorba officinalis (graph c) D) Centaurium erythrea (graph d)
33) Based on the van der Heijden et al. (1998) graphs in Figure 31.4, which of the following is the best 33)
description of the data supporting the idea that a plant species did not form mycorrhizae with a
fungus?
  1. Its biomass is greatest when no AMF are present.
  2. Its biomass is greatest when AM fungus B is present.
  3. Its biomass is greatest when AM fungus A is present.
  4. Its biomass is greatest when all AMF are present.
  5. Its biomass is greatest when AM fungus C is present.

 

 

 

 

 

 

 

8

 

34) Which of the following best explains the data given in graph (b) of Figure 31.4 about Lotus 34)
corniculatus?
  1. This plant grows best when AMF taxa A or C are present.
  2. This plant forms multiple AMF associations, growing best with increased fungal diversity.
  3. Lotus corniculatus does not form mycorrhizal associations.
  4. Mycorrhizal fungi parasitize the plant’s roots when they are present, reducing its growth.

 

Use the graphs in Figures 31.4 and 31.5 and the following information when answering the corresponding questions.

 

Canadian and Swiss researchers (van der Heijden et al., 1998), interested in factors affecting biodiversity, grew a variety of grassland plants in combination with one of four arbuscular mycorrhizal (AMF) species, no AMF, or all four AMF species together; and they measured plant growth under each set of conditions. All plant species were grown in each plot, so they always competed with each other with the only difference being which AMF were present. Use the graphs in Figure 31.5 to answer the questions that follow. Note that the x-axis labels indicate the number and identity of AMF species (bar 0 = no fungi; bars A–D = individual AMF species; bar A+B+C+D = all AMF species together). The y-axis indicates the amount (grams) of plant biomass for the species shown in italics above each graph. Graph (e) is the total biomass (grams) of all 11 plant species combined; graph (f) is the biomass of Bromus erectus plants only, separated from the total.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 31.4 Figure 31.5
35) What is the major difference between Bromus erectus (graph f) and the other plant species (graphs a 35)
–d) included in the study?
  1. Bromus produces very little biomass regardless of AMF.
  2. Bromus does not form mycorrhizal associations.
  3. Bromus grows best with a diversity of fungal partners.
  4. Bromus is unaffected by AMF diversity.

 

 

 

 

 

 

 

 

9

 

36) Why does total biomass (graph e Figure 31.5) not vary with AMF diversity? 36)
  1. Most of the plants in this system do not form mycorrhizal associations.
  2. Lotus corniculatus is a rare species.
  3. Bromus is the dominant plant species.
  4. Plant growth is unaffected by fungal diversity.

 

37) Based on graphs (e) and (f) in Figure 31.5, which is the most well-supported prediction for the 37)
effect on total plant biomass if AMF diversity were increased to eight species?
  1. No effect is predicted, because the dominant species is non-
  2. Total biomass for eight species would double in comparison to that for four species.
  3. Rare species would produce more biomass compared to the case when fewer AMF are present.
  4. No effect is predicted, because the dominant species is unaffected by AMF diversity.

 

 

 

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

 

1) A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to 1)
grow and divide are showing which type of cell-to-cell signaling?
A) endocrine B) paracrine C) neuroendocrine D) autocrine
2) You are dissecting a fish in your biology laboratory section. Your teaching assistant points out a 2)
long oval structure and tells you it is an endocrine gland. Which of the following would you then
know is a true statement about this structure?
  1. It secretes a product that is carried in the bloodstream or other fluids to target cells.
  2. The gland’s product will only interact with receptors on the cell membrane.
  3. The gland’s product is lipid soluble.
  4. The gland produces and secretes its product.

 

3) If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its 3)
appetite, one explanation is that the removed portion contains cells that secrete a chemical signal
that somehow stimulates appetite. Given this scenario, what type of chemical signaling is
occurring?
A) paracrine B) neuroendocrine C) endocrine D) autocrine
4) If a biochemist discovers a new molecule, which of the following pieces of data would allow her to 4)
draw the conclusion that the molecule is a steroid hormone?
A) The molecule is lipid soluble.
B) The molecule is derived from a series of steps beginning with cholesterol.
C) The molecule acts at a target tissue some distance from where it is produced.
D) The molecule uses a carrier protein when in an aqueous solution such as blood.
E) All of the above would indicate this molecule is a steroid hormone.
5) Which of the following is similar in structure to cholesterol? 5)
A) melanocyte-stimulating hormone and vasopressin
B) testosterone, estradiol, and cortisol
C) luteinizing hormone and insulin
D) oxytocin and vasopressin
E) leptin and serotonin
6) Polypeptides can have which of the following types of effects? 6)
A) autocrine B) paracrine C) endocrine D) all of the above
7) In experiments where researchers suspect that a hormone may be responsible for a certain 7)
physiological effect, they may cut the neurons leading to the organ where the effect being studied
occurs. What is the purpose of cutting these neurons?
  1. to make sure that the organ being affected cannot function unless the researchers stimulate it with an external electrical probe

 

  1. to impair the normal functions of the organ so that the hormonal effect can be more easily studied

 

  1. to make sure that the effect is not occurring through actions in the nervous system
  2. to numb the organ so that it can be probed without inducing pain in the lab animal

 

 

 

 

 

1

 

8) What is the only type of chemical signal that is not intended to alter the physiology of the animal 8)
producing that signal?
A) neural
B) paracrine
C) neuroendocrine
D) pheromones
E) only neural and neuroendocrine signals
9) Which of these glands is located within the abdominal cavity? 9)
A) pancreas
B) adrenal
C) parathyroid
D) thyroid
E) all of the above
10) What property of the steroid hormones allows them to cross the phospholipid bilayer? 10)
  1. Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.
  2. Steroid hormones can act in very small concentrations and very few molecules of steroids need to cross the lipid bilayer.
  3. Steroid hormones act on cells close to where they were produced and very few molecules are required to travel such a short distance to cross the lipid bilayer.

 

  1. Steroid hormones act on the same cells in which they are produced and therefore are within the cell they are acting upon.

 

  1. None of the above are true.

 

11) When partially digested food enters the small intestine from the stomach, several events must occur 11) to protect the intestine and allow for the continued digestion of the food. One hormone in

 

particular performs two of these functions. What intestinal hormone is responsible for causing the pancreas to release digestive enzymes and the gallbladder to release bile salts into the intestine?

  1. secretin
  2. corticosterone
  3. epinephrine
  4. insulin
  5. cholecystokinin

 

12) People with type II diabetes mellitus have defective insulin receptors that cannot respond to insulin 12) properly. Relative to normal individuals, what would be the effect on blood glucose levels of

 

chronic stress that kept blood cortisol levels high?

  1. There would be a greater increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.

 

  1. There would be less decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.

 

  1. There would be a greater decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.

 

  1. There would be less increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.

 

  1. There would be about the same effect on blood glucose levels in both types of individuals.

 

 

 

 

 

 

 

 

2

 

13) When a person drinks alcohol the rate of urination increases. This suggests that antidiuretic 13)

hormone (ADH) may be affected by alcohol consumption in some way. Which of the following could account for the increase in urination?

  1. Alcohol inhibits the release of ADH.
  2. Alcohol could inhibit ADH release or the binding of ADH to receptors in the nephron.
  3. Alcohol inhibits the binding of ADH to receptors in the nephron.
  4. Alcohol stimulates the release of ADH.

 

14) In human embryonic development, which of the following pairs of hormones are released by the 14)
developing testes and result in development of the male reproductive tract and inhibition of the
female reproductive tract?
A) estradiol and estrogen
B) testosterone and Mullerian inhibitory substance
C) testosterone and estrogen
D) estrogen and progesterone
E) testosterone and estradiol
15) Osteoporosis is a condition in which the density of bones is decreased so much that the individual 15)
is at a higher risk of fractures. The more calcium in the bones, the better the bone density. Which of
the following would have the greatest effect on calcium levels in the bones?
A) calcitonin injection B) parathyroid receptor blocker
C) parathyroid hormone injection D) calcitonin receptor blocker
16) You have three strains of mice: A, B, and C. You experimentally manipulate each strain and find 16)
that all three show increased secretion of molecule X. Now you perform a parabiosis experiment

with the three combinations of these mice: AB, AC, and BC. You perform the same experimental manipulation as above on one mouse of each pair without directly affecting the other mouse and look for effects on the other mouse. You find no detectable effect on the unmanipulated partner in any of the combinations. What is the logical conclusion based on these results?

  1. The effect on molecule X is not mediated by hormones.
  2. The effect on molecule X was just an artifact of the first experiment.
  3. The effect on molecule X is not mediated by nerves.
  4. The effect on molecule X is controlled by higher integrative centers of the brain.

 

17) Removing which of the following glands would have the most wide-reaching effect on bodily 17)
functions of an adult human?
A) pituitary gland B) ovaries (in female) or testes (in male)
C) adrenal glands D) thyroid gland
18) Predict the effects of a drug that increases adrenocorticotropic hormone (ACTH) synthesis. 18)
  1. increase in glucocorticoid production
  2. decrease in release of corticotropin-releasing hormone (CRH)
  3. increase in release of corticotropin-releasing hormone (CRH)
  4. decrease in cortisol release
  5. all of the above

 

 

 

 

 

 

 

 

 

 

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19) The regulation of blood sugar levels and our stress responses are controlled in part by a negative 19)
feedback loop involving cortisol, ACTH, and CRH. What would likely be the result during times of
stress if cortisol receptors in the hypothalamus were nonfunctional?
A) CRH production would cease.
B) ACTH production would cease.
C) Blood sugar levels would be unaffected.
D) Blood sugar levels would rise to dangerous levels.
E) Cortisol production would cease.
20) All of the following are examples of amplification of a hormone signal except _____. 20)
  1. epinephrine initiates an enzyme cascade
  2. steroids bind hormone-response elements in the cell and initiate gene transcription
  3. different cell types have different receptors capable of binding the same hormone
  4. 09 mg of growth hormone leads to a 10,000-mg weight gain in a cow

 

21) Which of the following hormone does not act via a second messenger system? 21)
A) insulin
B) norepinephrine
C) growth hormone
D) estrogen
E) ACTH
22) Which of the following statements correctly describes the relationship between the hypothalamus 22)
(H) and the anterior (AP) and posterior (PP) lobes of the pituitary?
A) The H regulates secretions from the PP, which then regulates all secretions from the AP.
B) The H communicates directly with the PP and indirectly with the AP through the circulatory
system.
C) The AP regulates the H through negative feedback mechanisms while the PP regulates the H
through positive feedback.
D) The H is the neural system that releases hormones directly into the AP and communicates
with the PP only through the circulation.
23) Which of the following best describes the neuroendocrine-to-endocrine pathway of hormone 23)
action?
  1. a gland that exhibits negative feedback on the nervous system by releasing hormones into neural tissue both directly and indirectly through the circulation

 

  1. a gland that releases hormones directly into a neural structure, thus regulating neural functions

 

  1. a neural organ that produces hormones regulates another gland through the release of hormones into the circulation that travel to the affected gland

 

  1. a neural organ that produces hormones releases its hormones directly into another gland that it regulates

 

24) Glucocorticoids do which of the following?                                                                                                                 24)

  1. A) promote the release of fatty acids B) promote the immune response
  2. C) increase blood glucose levels D) increase insulin production

 

 

 

 

 

 

 

 

 

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25) Prolactin tumors can cause a number of effects on the body. Which of the following might occur in 25)
a male patient?
A) acromegaly — the enlargement of the hands, feet, and jaw
B) excessive fat buildup in the face, neck, and abdomen
C) increase in heart rate
D) lactation
E) weight loss
26) How are small amounts of hormones amplified? 26)
  1. One cAMP molecule triggers the production of more hormone.
  2. One cAMP molecule stimulates one cAMP-dependent protein kinase A molecule, which activates many molecules of phosphorylase kinase.
  3. One cAMP molecule stimulates several cAMP-dependent protein kinase A molecules, which activates many molecules of phosphorylase kinase.

 

  1. Signal transduction cascades are dependent upon second messenger signaling only in rare cases and only when the hormone in question is a steroid.

 

27) Signal transduction occurs when a chemical message at the cell surface elicits a response inside the 27)
cell. Which one of the following events is not associated with signal transduction?
A) protein phosphorylation B) second messenger activation
C) cell-surface receptor binding D) internal receptor binding
28) Of the following types of molecules, which can function as both neurotransmitters and hormones? 28)
A) adipocytes B) glucocorticoids
C) second messengers D) catecholamines
29) Which of the following is true during a typical cAMP-type signal transduction event? 29)
  1. The hormone activates the second messenger by directly binding to it.
  2. Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation occurs.
  3. The second messenger amplifies the hormonal response by attracting more hormones to the cell being affected.

 

  1. The second messenger is the last part of the system to be activated.

 

30) Tadpoles must undergo a major metamorphosis to become frogs. This change includes 30)

reabsorption of the tail, growth of limbs, calcification of the skeleton, increase in rhodopsin in the eye, development of lungs, change in hemoglobin structure, and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore. Amazingly, all of these changes are induced by thyroxine. What is the most likely explanation for such a wide array of effects of thyroxine?

  1. There are many different forms of thyroxine, each specific to a different tissue.

 

  1. Different tissues have different types of receptors.
  2. Some tissues have membrane receptors for thyroxine, while other tissues have thyroxine receptors within the nucleus.
  3. Different releasing hormones release thyroxine to different tissues.

 

31) Patients diagnosed with hypercortisolism may have tumors that secrete _____. 31)
A) ACTH B) growth hormone
C) estrogen D) leptin

 

 

 

 

 

 

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32) Which of the following hormones does not act using a second messenger system? 32)
A) leptin B) testosterone
C) glucagon D) growth hormone
33) When adenylyl cyclase is activated ________. 33)
  1. G-proteins bind to cAMP
  2. cAMP is destroyed
  3. steroid hormones pass through the lipid bilayer
  4. cAMP is created

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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