Quiz 10

Question 1

Which of the following concepts/ideas reflects Lamarck’s perception of evolution?

a) gradualism
b) natural selection
c) use and disuse
d) the scala naturae

Answer 1

c) use and disuse

Question 2

Which of the following must exist in a population before natural selection can act upon that population?

a) genetic variation among individuals
b) variation among individuals caused by environmental factors
c) sexual reproduction
d) All of the above.

Answer 2

a) genetic variation among individuals

Question 3

If the bacterium Staphylococcus aureus expeirences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?

a) These genes should continue to be maintained in case the antibiotics ever appear.
b) These bacteria should be outcompeted and replaced by bacteria that have lost these genes.
c) The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present.
d) The bacteria should start making and secreting their own antibiotics.

Answer 3

b) These bacteria should be outcompeted and replaced by bacteria that have lost these genes.

Question 4

Biological diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution?

a) mistakes in translation of structural genes
b) mistakes in protein folding
c) binary fission
d) recombination by crossing over in meiosis

Answer 4

d) recombination by crossing over in meiosis

Question 5

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. Assuming that there are two alleles for that locus in the gene pool, what should be the frequency of the allele asscociated with the recessive phenotype?

a) 0.07
b) 0.09
c) 0.70
d) Allele frequency cannot be determined from this information.

Answer 5

d) Allele frequency cannot be determined from this information.

Question 6

Swine (pigs) are vulnerable to infection by bird flu virus and human flu virus, which can both be present in an individual pig at the same time. When this occurs, it is possible for genes from both flu viruses to be combined, thereby producing a genetically distinctive virus, which can subsequently cause widespread disease. The production of new types of flu virus in the manner described above is most similar to the phenonenon of

a) bottleneck effect
b) founder effect
c) natural selection
d) gene flow

Answer 6

d) gene flow

Question 7

A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. The actual forelimbs of these mammals do not seem to be optimally arranged because

a) natural selection has not had sufficient time to create the optimal design in each case, but will do so given enough time.
b) in many cases, phenotype is not merely determined by genotype, but by the environment as well.
c) though we may not consider the fit between the current skeletal arrangements and their functions to be excellent, we should not doubt that natural selection ultimately produces the best design.
d) natural selection is generally limited to modifying structures that were present in previous generations and in previous species.

Answer 7

d) natural selection is generally limited to modifying structures that were present in previous generations and in previous species.

Question 8

Which of the following is not an observation or inference on which natural selection is based?

a) There is heritable variation among individuals.
b) Poorly adapted individuals never produce offspring.
c) Species produce more offspring than the environment can support.
d) Only a fraction of an individual’s offspring may survive.

Answer 8

b) Poorly adapted individuals never produce offspring.

Question 9

Which of the following observations helped Darwin shape his concept of descent with modification?

a) Species diversity is lower farther from the equator.
b) Fewer species live on islands than on the nearest continents.
c) Birds live on islands located farther from the mainland than the birds’ maximum nonstop flight distance.
d) South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

Answer 9

d) South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe.

Question 10

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?

a) Forelimb evolution was adaptive in people and bats, but not in whales.
b) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
c) Genes mutate faster in whales than in humans or bats.
d) Whales are not properly classified as mammals.

Answer 10

b) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.

Question 11

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that

a) humans and chimpanzees share a relatively recent common ancestor.
b) humans evolved from chimpanzees.
c) chimpanzees evolved from humans.
d) convergent evolution led to the DNA similarities.

Answer 11

a) humans and chimpanzees share a relatively recent common ancestor.

Question 12

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
1. Well-adapted individuals leave more offspring than do poorly adapted individuals.
2. A change occurs in the environment.
3. Genetic frequencies within the population change.
4. Poorly adapted individuals have decreased survivorship.

Answer 12

2 → 4 → 1 → 3

Question 13

What must be true of any organ that is described as vestigial?

a) It must be both homologous and analogous to some feature in an ancestor.
b) It must be analogous to some feature in an ancestor.
c) It need be neither homologous nor analogous to some feature in an ancestor.
d) It must be homologous to some feature in an ancestor.

Answer 13

d) It must be homologous to some feature in an ancestor.

Question 14

If one wanted to find the largest number of endemic species, one should visit which of the following geological features (assuming each has existed for several millions of years)?

a) an extensive mountain range
b) an isolated ocean island in the tropics
c) a shallow estuary on a warm-water coast
d) a midcontinental grassland with extreme climatic conditions

Answer 14

b) an isolated ocean island in the tropics

Question 15

What is the best explanation for the emergence of resistant strains of Staphylococcus aureus?

a) In the presence of antibiotics, resistant bacteria in a population survive better than non-resistant bacteria, produce more offspring, and pass on the resistance to their offspring.
b) In many bacteria, artificial selection is stronger than natural selection.
c) Resistant strains of Staphylococcus aureus are more fit than nonresistant strains in all environments.
d) Antibiotics used to fight Staphylococcus aureus infections create resistance in the pathogen.
e) Resistance occurs in all organisms that have short generation times.

Answer 15

a) In the presence of antibiotics, resistant bacteria in a population survive better than non-resistant bacteria, produce more offspring, and pass on the resistance to their offspring.

Question 16

Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true?

a) Species X and Y are not related to species Z.
b) Species X and Y share a common ancestor that is still extant (in other words, not yet extinct).
c) Species X and Y are the result of artificial selection from an ancestral species Z.
d) Species X, Y, and Z share a common ancestor, but nothing more can be claimed than this.
e) Species X and Y share a greater number of homologies with each other than either does with species Z.

Answer 16

e) Species X and Y share a greater number of homologies with each other than either does with species Z.

Question 17

In the formula for determining a population’s genotype frequencies, the 2 in the term 2pq is necessary because

a) the population is doubling in number.
b) heterozygotes can come about in two ways.
c) the population is diploid.
d) heterozygotes have two alleles.

Answer 17

b) heterozygotes can come about in two ways.

Question 18

Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence?

a) gene flow
b) natural selection
c) genetic drift
d) nonrandom mating
e) mutation

Answer 18

c) genetic drift

Question 19

In the formula for determining a population’s EQUILIBRIUM genotype frequencies, the pq in the term 2pq is necessary because

a) heterozygotes have two alleles.
b) heterozygotes can come about in two ways.
c) the population is doubling in number.
d) the population is diploid.

Answer 19

a) heterozygotes have two alleles.

Question 20

Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree?

a) None of the organisms depicted by the tree ate the same foods.
b) Some of the organisms depicted by the tree had lived in different habitats.
c) Transitional fossils had not been found.
d) Relationships between DNA sequences among the species did not match relationships between skeletal patterns.
e) The skeletal remains of the organisms depicted by the tree were incomplete (in other words, some bones were missing).

Answer 20

d) Relationships between DNA sequences among the species did not match relationships between skeletal patterns.

Question 21

Which of Darwin’s ideas had the strongest connection to Darwin having read Malthus’s essay on human population growth?

a) that the ancestors of the Galápagos finches had come from the South American mainland
b) descent with modification
c) the ability of related species to be conceptualized in “tree thinking”
d) struggle for existence
e) variation among individuals in a population

Answer 21

d) struggle for existence

Question 22

Which of the following statements best describes theories?

a) They cannot be tested because the described events occurred only once.
b) They are nearly the same things as hypotheses.
c) They are predictions of future events.
d) They are supported by, and make sense of, many observations.

Answer 22

d) They are supported by, and make sense of, many observations.

Question 23

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?

a) by the principle of convergent evolution
b) by proposing that humans, bats, and dolphins share a common ancestor
c) by identifying the bones as being homologous structures
d) Three of the statements above are correct.
e) Two of the statements above are correct.

Answer 23

e) Two of the statements above are correct.

Question 24

A conservation organization has been trying to eliminate introduced species and encourage the growth/spread of native species. After several years, the balloon vine has almost totally replaced the goldenrain tree in the experimental plot. Based on your knowledge of evolution, which of the following outcomes would appear to be the most logical?

a) Intermediate beak length will be favoured just in case the introduced goldenrain tree makes a comeback.
b) Half of the soapberry bugs will die.
c) Variation in beak size will remain present in the soapberry bug population, but natural selection will favour beak lengths that are best adapted to the current food source.
b) The genes for short beaks will be lost.
e) To save soapberry bugs with short beaks, the researchers must relocate them to a different plot.

Answer 24

c) Variation in beak size will remain present in the soapberry bug population, but natural selection will favour beak lengths that are best adapted to the current food source.

Question 25

Evolution

a) requires that populations become better suited to their environments.
b) requires the operation of natural selection.
c) must happen whenever a population is not well-adapted to its environment.
d) must happen, due to organisms’ innate desire to survive.
e) can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met.

Answer 25

e) can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met.

Question 26

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.1. What is the frequency of individuals with AA genotype?

a) 0.32
b) 0.42
c) 0.20
d) 0.81

Answer 26

d) 0.81

Question 27

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants.

What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait (aa) has not changed over time?

a) There has been sexual selection favouring allele a.
b) The genotype AA is lethal.
c) There has been a high rate of mutation of allele A to allele a.
d) The population is undergoing genetic drift.
e) The two phenotypes are about equally adaptive under laboratory conditions.

Answer 27

e) The two phenotypes are about equally adaptive under laboratory conditions.

Question 28

Which of the following statements is a misconception about evolution of populations?

a) Without genetic variation, evolution would not be possible.
b) For a population to evolve, individual members of the population must also evolve.
c) Most heritable variation involves quantitative characters.
d) Natural selection acts on individuals.
e) Microevolution is a change in the genetic structure of a population over time.

Answer 28

b) For a population to evolve, individual members of the population must also evolve.

Question 29

How many of these statements regarding populations are true?

1. Mature males and females of a population can interbreed with each other.
2. Populations are sometimes geographically isolated from other populations.
3. Biological species are made up of populations.
4. Members of a population tend to be genetically more similar to each other than to members of other populations.
5. Populations have genomes, but not gene pools.

Answer 29

Four of these statements are true

Question 30

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?

a) analogous; analogous
b) homologous; analogous
c) analogous; homologous
d) homologous; homologous

Answer 30

b) homologous; analogous

Question 31

A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of

a) genetic drift.
b) relative fitness.
c) a cline.
d) geographic variation.
e) a bottleneck.

Answer 31

c) a cline.

Question 32

The three main mechanisms that alter allele frequencies and change the genetic composition of populations are

a) natural selection, bottleneck effect, and founder effect.
b) natural selection, random mating, and gene flow.
c) natural selection, genetic drift, and gene flow.
d) natural selection, gene flow, and large population size.
e) natural selection, gene flow, and random mating.

Answer 32

c) natural selection, genetic drift, and gene flow.

Question 33

Charles Darwin was the first person to propose

a) a mechanism for how evolution occurs.
b) a mechanism for evolution that was supported by evidence.
c) that evolution occurs.
d) that Earth is older than a few thousand years.
e) that population growth can outpace the growth of food resources.

Answer 33

b) a mechanism for evolution that was supported by evidence.

Question 34

Which of the following statements is a misconception about evolution of populations?

a) Without genetic variation, evolution would not be possible.
b) For a population to evolve, individual members of the population must also evolve.
c) Most heritable variation involves quantitative characters.
d) Natural selection acts on individuals.
e) Microevolution is a change in the genetic structure of a population over time.

Answer 34

b) For a population to evolve, individual members of the population must also evolve.

Question 35

Consider the human arm, a dog’s foreleg, and a seal’s flipper. These three structures are examples of ________ structures.

a) related
b) mammalian
c) analogous
d) similar function in
e) homologous

Answer 35

e) homologous

Question 36

In a hypothetical environment, fish called pike-cichlids are visual predators of algae-eating fish (in other words, they locate their prey by sight). If a population of algae-eaters experiences predation pressure from pike-cichlids, which of the following is least likely to be observed in the algae-eater population over the course of many generations?

a) selection for larger female algae-eaters, bearing broods composed of more, and larger, young
b) selection for nocturnal algae-eaters (active only at night)
c) selection for algae-eaters that are faster swimmers
d) selection for drab colouration of the algae-eaters
e) selection for algae-eaters that become sexually mature at smaller overall body sizes

Answer 36

a) selection for larger female algae-eaters, bearing broods composed of more, and larger, young

Question 37

The existence of the phenomenon of exaptation is most closely associated with which of the following observations that natural selection cannot fashion perfect organisms?

a) Chance events affect the evolutionary history of populations in environments that can change unpredictably.
b) Evolution is limited by historical constraints.
c) Adaptations are often compromises.
d) Natural selection and sexual selection can work at cross-purposes to each other.

Answer 37

b) Evolution is limited by historical constraints.

Question 38

Speciation

a) occurs only by the accumulation of genetic change over vast expanses of time.
b) can involve changes to a single gene.
c) occurs at such a slow pace that no one has ever observed the emergence of new species.
d) must begin with the geographic isolation of a small, frontier population.
e) and microevolution are synonymous.

Answer 38

b) can involve changes to a single gene.

Question 39

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new infections were caused by MRSA. How can this result best be explained?

a) S. aureus can resist vaccines.
b) A patient must have become infected with MRSA from another community.
c) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug.
d) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Answer 39

c) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug.

Question 40

Hardy-Weinberg equilibrium must occur in populations wherein

a) no genetic variation exists.
b) an allele remains fixed.
c) natural selection is not operating.
d) All three of the responses above are correct.
e) Only two of the responses above are correct.

Answer 40

e) Only two of the responses above are correct.

Question 41

In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution?

a) binary fission
b) mistakes in protein folding
c) recombination by crossing over in meiosis
d) rampant changes to the dictionary of the genetic code
e) mistakes in translation of structural genes

Answer 41

c) recombination by crossing over in meiosis

Question 42

DDT was once considered a “silver bullet” that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run?

a) The frequency of DDT application should have been higher.
b) DDT application should have been continual.
c) All habitats should have received applications of DDT at about the same time.
d) Larger doses of DDT should have been applied.
e) None of the individual insects should have possessed genomes that made them resistant to DDT.

Answer 42

e) None of the individual insects should have possessed genomes that made them resistant to DDT.

Question 43

Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?

a) All organisms have undergone evolution.
b) All organisms reproduce.
c) All organisms require energy.
d) All organisms show heritable variation.
e) All organisms use essentially the same genetic code.

Answer 43

e) All organisms use essentially the same genetic code.

Question 44

Of the following anatomical structures, which is homologous to the bones in the wing of a bird?

a) chitinous struts in the wing of a butterfly
b) bones in the hind limb of a kangaroo
c) bony rays in the tail fin of a flying fish
d) bones in the flipper of a whale
e) cartilage in the dorsal fin of a shark

Answer 44

d) bones in the flipper of a whale

Question 45

If two modern organisms are distantly related in an evolutionary sense, then one should expect that

a) they live in very different habitats.
b) they should be members of the same genus.
c) their chromosomes should be very similar.
d) they should share fewer homologous structures than two more closely related organisms.
e) they shared a common ancestor relatively recently.

Answer 45

d) they should share fewer homologous structures than two more closely related organisms.

Question 46

If Darwin had been aware of genes, and of their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement?

a) If natural selection can change one gene’s frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones.
b) If an individual’s somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring.
c) A single mutation in a single gene in a single gamete will, if perpetuated, produce a new species within just two generations.
d) If an individual acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will be the result.

Answer 46

a) If natural selection can change one gene’s frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones.

Question 47

Which of the following is a true statement concerning genetic variation?

a) It must be present in a population before natural selection can act upon the population.
b) It arises in response to changes in the environment.
c) A population that has a higher average heterozygosity has less genetic variation than one with a lower average heterozygosity.
d) It is created by the direct action of natural selection.
e) It tends to be reduced by the processes involved when diploid organisms produce gametes.

Answer 47

a) It must be present in a population before natural selection can act upon the population.

Question 48

You are studying three populations of birds. Population A has ten birds, of which one is brown (a recessive trait) and nine are red. Population B has 100 birds, of which ten are brown. Population C has 30 birds, and three of them are brown.

Which population is most likely to be subject to the bottleneck effect?

a) population A
b) population B
c) population C
d) They are all equally likely

Answer 48

a) population A

Question 49

The Hardy-Weinberg equilibrium theorem

a) applies to populations that exhibit low rates of mutation.
b) applies to extremely small populations that are subject to genetic drift.
c) describes a hypothetical population that is not evolving.
d) describes two or more populations that interbreed with one another.
e) applies to populations that show differential survival and reproductive success.

Answer 49

c) describes a hypothetical population that is not evolving.

Question 50

During a study session about evolution, one of your fellow students remarks, “The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result.” Which statement is most likely to be helpful in correcting this student’s misconception?

a) Characteristics acquired during an organism’s life are generally not passed on through genes.
b) If the giraffes did not have to compete with each other, longer necks would not have been passed on to the next generation.
c) Spontaneous mutations can result in the appearance of new traits.
d) Disuse of an organ may lead to its eventual disappearance.
e) Only favourable adaptations have survival value.

Answer 50

a) Characteristics acquired during an organism’s life are generally not passed on through genes.

Question 51

Which of the following statements best summarizes evolution as it is viewed today?

a) It represents the result of selection for acquired characteristics.
b) It is the differential survival and reproduction of the most-fit phenotypes.
c) It is synonymous with the process of gene flow.
d) It is the descent of humans from the present-day great apes.

Answer 51

b) It is the differential survival and reproduction of the most-fit phenotypes.

Question 52

In those parts of equatorial Africa where the malaria parasite is most common, the sickle-cell allele constitutes 20% of the β hemoglobin alleles in the human gene pool.

What should be the proportion of heterozygous individuals in populations that live here?

a) 0.04
b) 0.16
c) 0.20
d) 0.32
e) 0.80

Answer 52

d) 0.32

Question 53

There are those who claim that the theory of evolution cannot be true because the apes, which are supposed to be closely related to humans, do not likewise share the same large brains, capacity for complicated speech, and tool-making capability. They reason that if these features are generally beneficial, then the apes should have evolved them as well. Which of these provides the best argument against this misconception?

a) Advantageous alleles do not arise on demand.
b) Evolution can be influenced by environmental change.
c) A population’s evolution is limited by historical constraints.
d) Adaptations are often compromises.

Answer 53

a) Advantageous alleles do not arise on demand.

Question 54

Natural selection is based on all of the following EXCEPT

a) the best-adapted individuals tend to leave the most offspring.
b) individuals adapt to their environments and, thereby, evolve.
c) individuals who survive longer tend to leave more offspring than those who die young.
d) populations tend to produce more individuals than the environment can support.
e) genetic variation exists within populations.

Answer 54

b) individuals adapt to their environments and, thereby, evolve.

Question 55

Linnaeus was a “fixist” who believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with

a) nested, ever-more inclusive categories of organisms.
b) classifying organisms using the morphospecies concept.
c) the scientific discipline known as taxonomy.
d) a hierarchical classification scheme.
e) phylogenies.

Answer 55

e) phylogenies.