AP Bio Unit 7 Evolution

Mastering Biology Qs

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it _____.

1. dismissed the idea that species are constant and emphasized the importance of variation and change in populations

2. was the first time a biologist had proposed that species changed through time

3. proved that individuals acclimated to their environment over time

4. was the first theory to refute the ideas of special creation

1. dismissed the idea that species are constant and emphasized the importance of variation and change in populations

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?

1. Disuse of an organ may lead to its eventual disappearance.

2. Characteristics acquired during an organism's life are generally not passed on through genes.

3. Spontaneous mutations can result in the appearance of new traits.

4. Only favorable adaptations have survival value.

2. Characteristics acquired during an organism's life are generally not passed on through genes.

The following question refer to the figure below, which shows an outcrop of sedimentary rock whose strata are labeled A-D.

If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?

1. three strata

2. two strata

3. one stratum

4. four strata

2. two strata

Parasitic species tend to have simple morphologies. Which of the following statements best explains this observation?

1. Parasites do not live long enough to inherit acquired characteristics.

2. Parasites are lower organisms, and this is why they have simple morphologies.

3. Simple morphologies convey some advantage in most parasites.

4. Parasites have not yet had time to progress, because they are young evolutionarily.

3. Simple morphologies convey some advantage in most parasites.

A population of organisms will not evolve if _____.

1. the population lives in a habitat without competing species present

2. all individual variation is due only to environmental factors

3. the environment is changing at a relatively slow rate

4. the population size is large

2. all individual variation is due only to environmental factors

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?

1. Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future.

2. Earth changed over the years through a series of catastrophic upheavals.

3. Populations tend to increase at a faster rate than their food supply normally allows.

4. The environment is responsible for natural selection

3. Populations tend to increase at a faster rate than their food supply normally allows.

A biologist studied a population of squirrels for fifteen years. During that time, the population was never fewer than thirty squirrels and never more than forty-five. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to eighty. Which inference(s) about this most recent surge in the population size might be true?

1. The amount of available food may have increased.

2. The number of predators that prey upon squirrels may have decreased.

3. The amount of available food may have increased and/or the predators that prey upon squirrels may have decreased.

4. The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight.

3. The amount of available food may have increased and/or the predators that prey upon squirrels may have decreased.

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

1. the population has predators

2. genetic variation among individuals

3. variation among individuals caused by environmental factors

4. sexual reproduction

2. genetic variation among individuals

The role that humans play in artificial selection is to _____.

1. determine who lives and who dies

2. create genetic diversity

3. perform artificial insemination

4. choose which organisms reproduce

4. choose which organisms reproduce

In a hypothetical environment, fishes called pike-cichlids are visual predators of large, adult algae-eating fish (in other words, they locate their prey by sight). The population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following is least likely to occur in the algae-eater population in future generations?

1. selection for larger female algae-eaters, bearing broods composed of more, and larger, young

2. selection for nocturnal algae-eaters (active only at night)

3. selection for drab coloration of the algae-eaters

4. selection for algae-eaters that become sexually mature at smaller overall body sizes

1. selection for larger female algae-eaters, bearing broods composed of more, and larger, young

Which of the following evidence most strongly supports the common origin of all life on Earth? All organisms _____.

1. use essentially the same genetic code

2. reproduce

3. require energy

4. show heritable variation

1. use essentially the same genetic code

What must be true of any organ described as vestigial?

1. It must be analogous to some feature in an ancestor.

2. It must be homologous to some feature in an ancestor.

3. It must be both homologous and analogous to some feature in an ancestor.

4. It need be neither homologous nor analogous to some feature in an ancestor.

2. It must be homologous to some feature in an ancestor.

The following question refer to the evolutionary tree in the figure below.

The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.

How many distinct species, both living and extinct, are depicted in this tree?

1. five

2. six

3. nine

4. eleven

4. eleven

Which of the following is the best modern definition of evolution?

1. change in the number of genes in a population over time

2. survival of the fittest

3. descent with modification

4. inheritance of acquired characters

3. descent with modification

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

1. The frequency of the strong-beak alleles increased in each bird as the drought persisted.

2. Each bird evolved a deeper, stronger beak as the drought persisted.

3. Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.

4. Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation.

3. Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.

Which statement about variation is true?

1. All genetic variation produces phenotypic variation.

2. All new alleles are the result of nucleotide variability.

3. All nucleotide variability results in neutral variation.

4. All phenotypic variation is the result of genotypic variation.

2. All new alleles are the result of nucleotide variability.

The following experiment is used for the corresponding question.

A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers. But caterpillars that hatch in summer feed on oak leaves and look like oak twigs.

How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below.

In each of the four environments, one of the caterpillars was fed oak flowers, the other oak leaves. Thus, there were a total of eight treatment groups (4 environments × 2 diets).

Refer to the accompanying figure. Which one of the following is NOT a plausible hypothesis to explain the differences in caterpillar appearance observed in this population?

1. Differences in diet trigger the development of different types of caterpillars.

2. The cooler temperatures of spring trigger the development of flowerlike caterpillars.

3. Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars.

4. The longer day lengths of summer trigger the development of twig-like caterpillars.

3. Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars.

The following experiment is used for the corresponding question.

A researcher discovered a species of moth that lays its eggs on oak trees. Eggs are laid at two distinct times of the year: early in spring when the oak trees are flowering and in midsummer when flowering is past. Caterpillars from eggs that hatch in spring feed on oak flowers and look like oak flowers. But caterpillars that hatch in summer feed on oak leaves and look like oak twigs.

How does the same population of moths produce such different-looking caterpillars on the same trees? To answer this question, the biologist caught many female moths from the same population and collected their eggs. He put at least one egg from each female into eight identical cups. The eggs hatched, and at least two larvae from each female were maintained in one of the four temperature and light conditions listed below.

In each of the four environments, one of the caterpillars was fed oak flowers, the other oak leaves. Thus, there were a total of eight treatment groups (4 environments × 2 diets).

Refer to the accompanying figure. In every case, caterpillars that feed on oak flowers look like oak flowers. In every case, caterpillars that were raised on oak leaves looked like twigs. These results support which of the following hypotheses?

1. Differences in diet trigger the development of different types of caterpillars.

2. The cooler temperatures of spring trigger the development of flowerlike caterpillars.

3. Differences in air pressure, due to differences in elevation, trigger the development of different types of caterpillars.

4. The longer day lengths of summer trigger the development of twig-like caterpillars.

1. Differences in diet trigger the development of different types of caterpillars.

Use the following information to answer the question(s) below.

Researchers studying a small milkweed population note that some plants produce a toxin and other plants do not. They identify the gene responsible for toxin production. The dominant allele (T) codes for an enzyme that makes the toxin, and the recessive allele (t) codes for a nonfunctional enzyme that cannot produce the toxin. Heterozygotes produce an intermediate amount of toxin. The genotypes of all individuals in the population are determined (see chart) and used to determine the actual allele frequencies in the population.

Refer to the figure above. Is this population in Hardy-Weinberg equilibrium?

1. Yes

2. No; there are more homozygotes than expected

3. No; there are more heterozygotes than expected

4. More information is needed to answer this question

2. No; there are more homozygotes than expected

Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus, _____.

1. natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency

2. individuals within the population are evolving

3. two alleles are present in equal proportions

4. the allele's frequency should not change from one generation to the next

4. the allele's frequency should not change from one generation to the next

In the formula for determining a populations genotype frequencies, the "pq" in the term 2pq is necessary because _____.

1. the population is diploid

2. the population is doubling in number

3. heterozygotes can come about in two ways

4. heterozygotes have two alleles

4. heterozygotes have two alleles

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?

1. 0.09

2. 0.9

3. 0.49

4. 9.0

1. 0.09

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals that are heterozygous for this allele?

1. 0.020

2. 0.32

3. 0.16

4. 0.04

2. 0.32

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population?

1. 0.70

2. 0.08

3. 0.09

4. Allele frequency cannot be determined from this information

4. Allele frequency cannot be determined from this information

The following question(s) are based on information in Hopi E. Hoekstra, Kristen E. Drumm, and Michael W. Nachman, "Ecological Genetics of Adaptive Color Polymorphism in Pocket Mice: Geographic Variation in Selected and Neutral Genes," Evolution 58(6), 2004: 132941.

Refer to the figure above. In their investigation of natural selection on Mc1r alleles (the gene that determines coat color) in Arizona pocket mice, Hoekstra et al. determined the frequency of the D and d alleles in each population. They also determined the frequency of alleles for two neutral mitochondrial DNA genes (genes that do not affect and are not linked to coat color). Why did the researchers include the mitochondrial DNA genes as part of their experimental design?

1. Allele change for the neutral mitochondrial genes serves as an experimental group and gives information on coat-color differences among these populations.

2. Allele change for the neutral mitochondrial genes serves as an experimental group and gives information on any general background genetic difference among these populations.

3. Allele change for the neutral mitochondrial genes serves as a control and determines coat-color differences among these populations.

4. Allele change for the neutral mitochondrial genes serves as a control and gives information on any general background genetic difference among these populations.

4. Allele change for the neutral mitochondrial genes serves as a control and gives information on any general background genetic difference among these populations.

Soon after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the evolution of life on this new island should have been most strongly influenced by _____.

1. sexual selection

2. genetic bottleneck

3. founder effect

4. habitat differentiation

3. founder effect

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing _____.

1. gene flow

2. genetic drift

3. nonrandom making

4. geographic isolation

1. gene flow

You are maintaining a small population of fruit flies in the laboratory by transferring the flies to a new culture bottle after each generation. After several generations, you notice that the viability of the flies has decreased greatly. Recognizing that small population size is likely to be linked to decreased viability, the best way to reverse this trend is to _____.

1. cross your flies with flies from another lab

2. transfer only the largest flies

3. change the temperature at which you rear the flies

4. reduce the number of flies that you transfer at each generation

1. cross your flies with flies from another lab

Which of the following is a fitness trade-off (compromise)?

1. In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge.

2. The strong, thick beak of a woodpecker helps it find insects in trees.

3. Turtle shells provide protection but are heavy and burdensome when moving.

4. Hummingbirds are the best pollinators of certain flowers, but bees are the best pollinators for orchids.

3. Turtle shells provide protection but are heavy and burdensome when moving.

Martin Wikelski and L. Michael Romero (Body size, performance and fitness in Galápagos marine iguanas, Integrative and Comparative Biology 43 [2003]:376-86) measured the snout-to-vent (anus) length of Galápagos marine iguanas and observed the percent survival of different-sized animals, all of the same age. The graph shows the log snout-vent length (SVL, a measure of overall body size) plotted against the percent survival of these different size classes for males and females.

Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (for example, cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to _____ in the absence of other factors; the iguanas would then be under _____ selection.

1. increase; directional

2. decrease; directional

3. decrease; disruptive

4. increase; disruptive

2. decrease; directional

The restriction enzymes of bacteria protect the bacteria from successful attack by bacteriophages, whose genomes can be degraded by the restriction enzymes. The bacterial genomes are not vulnerable to these restriction enzymes because bacterial DNA is methylated. This situation selects for bacteriophages whose genomes are also methylated. As new strains of resistant bacteriophages become more prevalent, this in turn selects for bacteria whose genomes are not methylated and whose restriction enzymes instead degrade methylated DNA. The outcome of the conflict between bacteria and bacteriophage at any point in time results from _____.

1. frequency-dependent selection

2. neutral variation

3. heterozygote advantage

4. evolutionary imbalance

1. frequency-dependent selection

Arrange the following in order from most general to most specific.

1 natural selection

2. microevolution

3. intrasexual selection

4. evolution

5. sexual selection

1, 4, 2, 5, 3

4, 2, 1, 3, 5

4, 2, 1, 5, 3

4, 1, 2, 3, 5

4, 2, 1, 5, 3

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 _____.

1. though we may not consider the fit between the current skeletal arrangements and their functions excellent, we should not doubt that natural selection ultimately produces the best design

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

3. in many cases, phenotype is determined by genotype and the environment

4. natural selection has not had sufficient time to create the optimal design in each case, but will do so given enough time

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

In a very large population, a quantitative trait has the following distribution pattern.

If there is no gene flow, the curve shifts to the left or to the right, and the population size consequently increases over successive generations, which of the following is most likely occurring?

1. genetic drift

2. directional selection

3. disruptive selection

4. immigration or emigration

2. directional selection

Macroevolution is _____.

1. the same as microevolution, but includes the origin of new species

2. defined as a change in allele or gene frequency over the course of many generations

3. evolution above the species level

4. defined as the evolution of microscopic organisms into organisms that can be seen with the naked eye

3. evolution above the species level

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?

1. morphological

2. biological

3. ecological

4. phylogenetic

2. biological

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?

1. temporal isolation

2. habitat isolation

3. gametic isolation

4. behavioral isolation

2. habitat isolation

The production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) is an example of _____.

1. mechanical isolation

2. hybrid breakdown

3. reduced hybrid viability

4. reduced hybrid fertility

4. reduced hybrid fertility

Two researchers experimentally formed tetraploid frogs by fertilizing diploid eggs from Rana porosa brevipoda with diploid sperm from Rana nigromaculata. When they mated these tetraploid frogs with each other, most of the offspring that survived to maturity were tetraploid, with chromosome sets of both diploid parent species. Based on these results, if this type of tetraploid formed in the wild, what would be the result? (Y. Kondo and A. Kashiwagi. 2004. Experimentally induced autotetraploidy and allotetraploidy in two Japanese pond frogs. Journal of Herpetology 38(3):381-92.)

1. The two parent species would interbreed and fuse into one species.

2. The tetraploids would be selected against.

3. The tetraploids would be reproductively isolated from both parent species.

4. The two parent species would recognize each other as mates.

3. The tetraploids would be reproductively isolated from both parent species.

In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In the western United States, pronghorns and cattle often associate with one another in the same open rangeland. Some of these fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood. The host mammal can be considered as the fleas' habitat. If this situation persists, and new species evolve, this would be an example of _____.

1. sympatric speciation and habitat isolation

2. sympatric speciation and temporal isolation

3. allopatric speciation and habitat isolation

4. allopatric speciation and gametic isolation

1. sympatric speciation and habitat isolation

Use the following description to answer the question(s) below.

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences.

Which two of the following have operated to increase divergence between mosquitofish populations on Andros?

1. improved gene flow

2. bottleneck effect

3. sexual selection

4. founder effect

5. natural selection

1 and 3

3 and 5

2 and 3

2 and 4

3 and 5

Use the following description to answer the question(s) below.

In the ocean, on either side of the Isthmus of Panama, are thirty species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are fifteen species on the Pacific side and fifteen different species on the Atlantic side. The Isthmus of Panama started rising about ten million years ago. The oceans were completely separated by the isthmus about three million years ago.

In the following figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest.

In which habitat should one find snapping shrimp most closely related to shrimp that live in habitat A4?

1. B4

2. A5

3. A3

4. either A3 or A5

1. B4

Use the following description to answer the question(s) below.

In the ocean, on either side of the Isthmus of Panama, are thirty species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are fifteen species on the Pacific side and fifteen different species on the Atlantic side. The Isthmus of Panama started rising about ten million years ago. The oceans were completely separated by the isthmus about three million years ago.

In the following figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest.

Which habitats should harbor snapping shrimp species with the greatest degree of genetic divergence from each other?

1. A1 and B5

2. A1 and A5

3. A5 and B5

4. Both A1/A5 and B1/B5 should have the greatest, but equal amounts of, genetic divergence

3. A5 and B5

Use the following description to answer the question(s) below.

In the ocean, on either side of the Isthmus of Panama, are thirty species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are fifteen species on the Pacific side and fifteen different species on the Atlantic side. The Isthmus of Panama started rising about ten million years ago. The oceans were completely separated by the isthmus about three million years ago.

In the following figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest.

Which factor is most important for explaining why there are equal numbers of snapping shrimp species on either side of the isthmus?

1. the number of actual depth habitats between the surface and the sea floor

2. the relative shortness of time they have been separated

3. the elevation of the isthmus above sea level

4. the depth of the ocean

2. the relative shortness of time they have been separated

Speciation _____.

1. must begin with the geographic isolation of a small, frontier population

2. can involve changes to a single gene

3. occurs at such a slow pace that no one has ever observed the emergence of new species

4. occurs only by the accumulation of small genetic changes over vast expanses of time

2. can involve changes to a single gene

Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?

1. a behavioral reproductive isolating mechanism

2. a temporal reproductive isolating mechanism

3. a postzygotic isolating mechanism

4. a gametic reproductive isolating mechanism

1. a behavioral reproductive isolating mechanism

How were conditions on the early Earth of more than three billion years ago different from those on today's Earth? Unlike Earth today, early Earth _____.

1. experienced little high energy radiation from the sun

2. had an oxidizing atmosphere

3. had an atmosphere rich in gases released from volcanic eruptions

4. had an atmosphere with significant quantities of ozone

3. had an atmosphere rich in gases released from volcanic eruptions

The questions below refer to the following description and figure.

The figure below represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities. At the arrow labeled "I" (the rift valley), the igneous rock of the sea floor is so young that it can be accurately dated using carbon-14 dating. At the arrow labeled "III," however, the igneous rock is about one million years old, and potassium-40 dating is typically used to date such rocks. Note: The horizontal arrows indicate the direction of sea-floor spreading, away from the rift valley.

Which section of sea-floor crust should have the thickest layer of overlying sediment, assuming a continuous rate of sediment deposition?

1. A

2. B

3. D

4. E

4. E

Which of the following organisms would be most likely to fossilize?

1. a common worm

2. a common squirrel

3. a rare squirrel

4. a rare worm

2. a common squirrel

Which of the following would be LEAST likely in the fossil record?

1. marsh-dwelling species

2. marine-dwelling species

3. desert-dwelling species

4. burrowing species

3. desert-dwelling species

What is true of the fossil record of mammalian origins?

1. It includes transitional forms with progressively specialized teeth.

2. It shows that mammals and birds evolved from the same kind of dinosaur.

3. It indicates that mammals and dinosaurs did not overlap in geologic time.

4. It includes a series that shows the gradual change of scales into fur.

1. It includes transitional forms with progressively specialized teeth.

A sediment core is removed from the floor of an inland sea. The sea has been in existence, off and on, throughout the entire time that terrestrial life has existed. Researchers wish to locate and study the terrestrial organisms fossilized in this core. The core is illustrated as a vertical column, with the top of the column representing the most recent strata and the bottom representing the time when land was first colonized by life.

To assign absolute dates to fossils in this sediment core, it would be most helpful if _____.

1. we knew the order in which the fossils occurred

2. the sediments had not been affected by underwater currents during their deposition

3. fossils throughout the column were equally spaced apart

4. volcanic ash layers were regularly interspersed between the sedimentary strata

4. volcanic ash layers were regularly interspersed between the sedimentary strata

What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth?

1. origin of mitochondria

2. origin of multicellular eukaryotes

3. origin of chloroplasts

4. origin of cyanobacteria

5. origin of fungal-plant symbioses

4, 3, 1, 5, 2

4, 1, 3, 2, 5

4, 1, 2, 3, 5

4, 3, 2, 1, 5

4, 1, 3, 2, 5

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to _____.

1. make it easier to maintain reduced molecules

2. change the atmosphere from oxidizing to reducing

3. cause iron in ocean water and terrestrial rocks to rust (oxidize)

4. prevent the formation of an ozone layer

3. cause iron in ocean water and terrestrial rocks to rust (oxidize)

Which of the following characteristics are expected in the first animals to have colonized land?

1. were probably herbivores (ate photosynthesizers)

2. had four appendages

3. had the ability to resist dehydration

4. had lobe-finned fishes as ancestors

5. were invertebrates

1, 2, 3, and 4

1, 3, and 5

3 and 5

3 only

1, 3, and 5

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?

1. The climates of the two regions are similar.

2. Life in India was wiped out by ancient volcanic eruptions.

3. India is in the process of separating from the rest of Asia.

4. India was a separate continent until forty-five million years ago.

4. India was a separate continent until forty-five million years ago.

What does the circled part of the phylogenetic tree above indicate?

1. an adaptive radiation and rapid speciation

2. a mass extinction event

3. an adaptive radiation

4. rapid speciation

1. an adaptive radiation and rapid speciation

According to the theory of sea-floor spreading, oceanic islands, such as the Hawaiian Islands depicted in the figure above, form as oceanic crustal plates move over a stationary "hot spot" in the mantle. Currently, the big island of Hawaii is thought to be over a hot spot, which is why it is the only one of the seven large islands that has active volcanoes. What should be true of the island of Hawaii?
1. Scientists in search of ongoing speciation events are more likely to find them here than on the other six large islands.
2. Its species should be more closely related to those of nearer islands than to those of farther islands.
3. It should have a rich fossil record of terrestrial organisms.
4. It should have species that are not found anywhere else on Earth.
5. On average, it should have fewer species per unit surface area than the other six islands.

1, 2, and 5

1, 2, and 3

1, 2, 4, and 5

1, 2, 3, and 4

1, 2, 4, and 5

Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

1. mass extinctions, leading to bottleneck effect

2. adaptive radiation, leading to founder effect

3. major evolutionary innovations, leading to rafting to nearby continents

4. a variety of empty ecological niches, leading to adaptive radiation

4. a variety of empty ecological niches, leading to adaptive radiation

The duplication of homeotic (Hox) genes has been significant in the evolution of animals because it _____.

1. permitted the evolution of novel forms

2. allowed animals to survive on significantly fewer calories

3. reduced morphological diversity into simpler forms of life

4. caused the extinction of major groups

1. permitted the evolution of novel forms

The following question are based on the observation that several dozen different proteins comprise the prokaryotic flagellum and its attachment to the prokaryotic cell, producing a highly complex structure.

Certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This evidence supports the claim that _____.

1. bacteria that possess flagella must have lost the ability to pump certain chemicals across their plasma membranes

2. natural selection can produce new structures by coupling together parts of other structures

3. natural selection produces organs that will be needed in future environments

4. the motors of bacterial flagella must have originated in other organisms

2. natural selection can produce new structures by coupling together parts of other structures

The questions below refer to the following phylogenetic trees.

I. II.

III. IV.

Which tree depicts the closest relationship between zygomycetes and chytrids?

III.

The legless condition that is observed in several groups of extant reptiles is the result of _____.

1. their common ancestor having been legless

2. a shared adaptation to an arboreal (living in trees) lifestyle

3. individual lizards adapting to a fossorial (living in burrows) lifestyle during their lifetimes

4. several instances of the legless condition arising independently of each other

4. several instances of the legless condition arising independently of each other

The various taxonomic levels (for example, phyla, genera, classes) of the hierarchical classification system differ from each other on the basis of _____.

1. how widely the organisms assigned to each are distributed throughout the environment

2. morphological characters that are applicable to all organisms

3. their inclusiveness

4. the relative genome sizes of the organisms assigned to each

3. their inclusiveness

The best classification system is that which most closely _____.

1. unites organisms that possess similar morphologies

2. reflects the basic separation of prokaryotes from eukaryotes

3. reflects evolutionary history

4. conforms to traditional, Linnaean taxonomic practices

3. reflects evolutionary history

Based on this tree, which statement is NOT correct?

1. Lizards are more closely related to salamanders than to humans.

2. The salamander lineage is a basal taxon.

3. Salamanders are as closely related to goats as to humans.

4. Salamanders are a sister group to the group containing lizards, goats, and humans.

1. Lizards are more closely related to salamanders than to humans.

Which of the following pairs are the best examples of homologous structures?

1. owl wing and hornet wing

2. bones in the bat wing and bones in the human forelimb

3. bat wing and bird wing

4. eyelessness in the Australian mole and eyelessness in the North American mole

2. bones in the bat wing and bones in the human forelimb

The importance of computers and of computer software to modern cladistics is most closely linked to advances in _____.

1. light microscopy

2. molecular genetics

3. radiometric dating

4. fossil discovery techniques

2. molecular genetics

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as _____.

1. structural homologies

2. vestiges

3. homoplasies

4. the result of shared ancestry

3. homoplasies

Which of the following would be useful in creating a phylogenetic tree of a taxon?

I) morphological data from fossil species

II) genetic sequences from living species

III) behavioral data from living species

1. I

2. II

3. III

4. I, II, and III

4. I, II, and III

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?

1. to see if the lily is a cryptic orchid species

2. to serve as an outgroup

3. to demonstrate likely homoplasies

4. to see if the lily and the orchids show all the same shared derived characters (synapomorphies)

2. to serve as an outgroup

Which of the following statements best describes the rationale for applying the principle of parsimony in constructing phylogenetic trees?

1. The outgroup roots the tree, allowing the principle of parsimony to be applied.

2. The molecular clock validates the principle of parsimony.

3. Similarity due to common ancestry should be more common than similarity due to convergent evolution.

4. Parsimony allows the researcher to "root" the tree.

3. Similarity due to common ancestry should be more common than similarity due to convergent evolution.

Phylogenetic trees constructed from evidence from molecular systematics are based on similarities in _____.

1. the pattern of embryological development

2. biochemical pathways

3. mutations to homologous genes

4. morphology

3. mutations to homologous genes

In a comparison of birds and mammals, having four limbs is _____.

1. a character useful for distinguishing birds from mammals

2. an example of analogy rather than homology

3. a shared ancestral character

4. a shared derived character

3. a shared ancestral character

To apply parsimony to constructing a phylogenetic tree, _____.

1. choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

2. choose the tree in which the branch points are based on as many shared derived characters as possible

3. choose the tree that assumes all evolutionary changes are equally probable

4. choose the tree with the fewest branch points

1. choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma. These species have apparently undergone speciation from ancestral stock since the last glacial retreat about ten thousand years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species?

1. ribosomal RNA

2. conserved regions of nuclear DNA

3. mitochondrial DNA

4. amino acids in proteins

3. mitochondrial DNA

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves _____.

1. share a very recent common ancestor

2. have very similar morphologies

3. belong to the same order

4. are both members of the order Carnivora

1. share a very recent common ancestor

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that _____.

1. having multiple copies of genes is essential for the occurrence of sympatric speciation in the wild

2. polyploidy is a necessary precondition for the occurrence of sympatric speciation in the wild

3. paralogous genes can occur only in diploid species; thus, they are absent from most prokaryotes

4. having an extra copy of a gene permits modifications to the copy without loss of the original gene product

4. having an extra copy of a gene permits modifications to the copy without loss of the original gene product

The most important feature that permits a gene to act as a molecular clock is _____.

1. a reliable average rate of mutation

2. a recent origin by a gene-duplication event

3. being acted upon by natural selection

4. a large number of base pairs

1. a reliable average rate of mutation

The questions below refer to the following table, which compares the % sequence homology of four different parts (two introns and two exons) of a gene that is found in five different eukaryotic species. Each part is numbered to indicate its distance from the promoter (for example, Intron I is the one closest to the promoter). The data reported for species A were obtained by comparing DNA from one member of species A to another member of species A.

% Sequence Homology

Species	Intron I	Exon I	Intron VI	Exon V
A	100%	100%	100%	100%
B	98%	99%	82%	96%
C	98%	99%	89%	96%
D	99%	99%	92%	97%
E	98%	99%	80%	94%

Which of these four gene parts should allow the construction of the most accurate phylogenetic tree, assuming that this is the only part of the gene that has acted as a reliable molecular clock?

1. Exon V

2. Intron I

3. Exon I

4. Intron VI

4. Intron VI

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium?

1. Protista

2. Fungi

3. Animalia

4. Plantae

4. Plantae

The following question refer to this phylogenetic tree, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer.

A possible phylogenetic tree for the three domains of life.

Which portion of the figure above may ultimately be better depicted as a "ring"?

1. the eukaryotic lineage

2. the trunk of the tree

3. the archaean lineage

4. the bacterial lineage

2. the trunk of the tree