Gainesville Biology 1108 Test 1

Created by ccatmoore 

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Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of
A) evolution.
B) the fossil record.
C) uniformitarianism.
D) the origin of new species.
E) natural selection.

B. The fossil record

Which of the events described below agrees with the idea of catastrophism?
A) The gradual uplift of the Himalayas by the collision of the Australian crustal plate with the Eurasian crustal plate
B) The formation of the Grand Canyon by the Colorado River over millions of years
C) The gradual deposition of sediments many kilometers thick on the floors of seas and oceans
D) The sudden demise of the dinosaurs, and various other groups, by the impact of a large extraterrestrial body with Earth
E) The development of the Galapagos Islands from underwater seamounts over millions of years

D) The sudden demise of the dinosaurs, and various other groups, by the impact of a large extraterrestrial body with Earth

3) What was the prevailing notion prior to the time of Lyell and Darwin?
A) Earth is a few thousand years old, and populations are unchanging.
B) Earth is a few thousand years old, and populations gradually change.
C) Earth is millions of years old, and populations rapidly change.
D) Earth is millions of years old, and populations are unchanging.
E) Earth is millions of years old, and populations gradually change.

A) Earth is a few thousand years old, and populations are unchanging.

4) 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) Spontaneous mutations can result in the appearance of new traits.
C) Only favorable adaptations have survival value.
D) Disuse of an organ may lead to its eventual disappearance.
E) Overproduction of offspring leads to a struggle for survival.

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

5) Which group is composed entirely of individuals who maintained that species are fixed (i.e., unchanging)?
A) Aristotle, Cuvier, and Lamarck
B) Linnaeus, Cuvier, and Lamarck
C) Lyell, Linnaeus, and Lamarck
D) Aristotle, Linnaeus, and Cuvier
E) Hutton, Lyell, and Darwin

D) Aristotle, Linnaeus, and Cuvier

6) In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of
A) Cuvier.
B) Hutton.
C) Lamarck.
D) Darwin.
E) Plato.

C) Lamarck.

Who would have proposed that the boundaries between each stratum mark the occurrence of different localized floods?
A) Lyell
B) Cuvier
C) Hutton
D) Darwin
E) Lamarck

B) Cuvier

Which pair would have been likely to agree that strata such as those depicted here were deposited gradually over long periods of time by subtle mechanisms that are still at work?
A) Cuvier and Aristotle
B) Cuvier and Lamarck
C) Lyell and Linnaeus
D) Aristotle and Hutton
E) Hutton and Lyell

E) Hutton and Lyell

Darwin's mechanism of natural selection required long time spans in order to modify species. From whom did Darwin get the concept of Earth's ancient age?
A) Georges Cuvier
B) Charles Lyell
C) Alfred Wallace
D) Thomas Malthus
E) John Henslow

B) Charles Lyell

As a young biologist, Charles Darwin had expected the living plants of temperate South America would resemble those of temperate Europe, but he was surprised to find that they more closely resembled the plants of tropical South America. The biological explanation for this observation is most properly associated with the field of
A) meteorology.
B) embryology.
C) vertebrate anatomy.
D) bioengineering.
E) biogeography.

E) biogeography.

Which of these naturalists synthesized a concept of natural selection independently of Darwin?
A) Charles Lyell
B) Gregor Mendel
C) Alfred Wallace
D) John Henslow
E) Thomas Malthus

C) Alfred Wallace

Charles Darwin was the first person to propose
A) that evolution occurs.
B) a mechanism for how evolution occurs.
C) that the Earth is older than a few thousand years.
D) a mechanism for evolution that was supported by evidence.
E) a way to use artificial selection as a means of domesticating plants and animals.

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

In Darwin's thinking, the more closely related two different organisms are, the
A) more similar their habitats are.
B) less similar their DNA sequences are.
C) more recently they shared a common ancestor.
D) less likely they are to have the same genes in common.
E) more similar they are in size.

C) more recently they shared a common ancestor

Which of these conditions should completely prevent the occurrence of natural selection in a population over time?
A) All variation between individuals is due only to environmental factors.
B) The environment is changing at a relatively slow rate.
C) The population size is large.
D) The population lives in a habitat where there are no competing species present.

A) All variation between individuals is due only to environmental factors.

Natural selection is based on all of the following except
A) genetic variation exists within populations.
B) the best-adapted individuals tend to leave the most offspring.
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) individuals adapt to their environments and, thereby, evolve.

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

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?
A) All species are fixed in the form in which they are created.
B) Populations tend to increase at a faster rate than their food supply normally allows.
C) Earth changed over the years through a series of catastrophic upheavals.
D) The environment is responsible for natural selection.
E) Earth is more than 10,000 years old.

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

Which statement about natural selection is most correct?
A) Adaptations beneficial in one habitat should generally be beneficial in all other habitats as well.
B) Different species that occupy the same habitat will adapt to that habitat by undergoing the same genetic changes.
C) Adaptations beneficial at one time should generally be beneficial during all other times as well.
D) Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals.
E) Natural selection is the sole means by which populations can evolve.

D) Well-adapted individuals leave more offspring, and thus contribute more to the next generation's gene pool, than do poorly adapted individuals

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.
A) 2 → 4 → 1 → 3
B) 4 → 2 → 1 → 3
C) 4 → 1 → 2 → 3
D) 4 → 2 → 3 → 1
E) 2 → 4 → 3 → 1

A) 2 → 4 → 1 → 3

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?
A) The amount of available food may have increased.
B) The number of predators may have decreased.
C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive.
D) A and B only
E) A, B, and C

E) A, B, and C

To observe natural selection's effects on a population, which of these must be true?
A) One must observe more than one generation of the population.
B) The population must contain genetic variation.
C) Members of the population must increase or decrease the use of some portion of their anatomy.
D) A and C only
E) A and B only

E) A and B only

If the HMS Beagle had completely bypassed the Galapagos Islands, Darwin would have had a much poorer understanding of the
A) relative stability of a well-adapted population's numbers over many generations.
B) ability of populations to undergo modification as they adapt to a particular environment.
C) tendency of organisms to produce the exact number of offspring that the environment can support.
D) unlimited resources that support population growth in most natural environments.
E) lack of genetic variation among all members of a population.

B) ability of populations to undergo modification as they adapt to a particular environment.

During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?
A) Small birds gaining larger beaks by exercising their mouth parts.
B) Small birds mutating their beak genes with the result that later-generation offspring have larger beaks.
C) Small birds anticipating the long drought and eating more to gain weight and, consequently, growing larger beaks.
D) More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.
E) Larger birds eating less so smaller birds can survive.

D) More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.

Which of the following statements is an inference of natural selection?
A) Subsequent generations of a population should have greater proportions of individuals that possess traits better suited for success in unchanging environments.
B) An individual organism undergoes evolution over the course of its lifetime.
C) Habitats do not generally have unlimited resources.
D) Natural populations tend to reproduce to their full biological potential.
E) Some of the variation that exists among individuals in a population is genetic.

A) Subsequent generations of a population should have greater proportions of individuals that possess traits better suited for success in unchanging environments.

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) B and C only
E) A, B, and C

A) Genetic variation among individuals

Which of Darwin's ideas had the strongest connection to Darwin having read Malthus's essay on human population growth?
A) Descent with modification
B) Variation among individuals in a population
C) Struggle for existence
D) The ability of related species to be conceptualized in "tree thinking"
E) That the ancestors of the Galapagos finches had come from the South American mainland

C) Struggle for existence

How many separate species, both extant and extinct, are depicted in this tree?
A) 2
B) 3
C) 4
D) 5
E) 6

E) 6

Which pair would probably have agreed with the process that is depicted by this tree?
A) Cuvier and Lamarck
B) Lamarck and Wallace
C) Aristotle and Lyell
D) Wallace and Linnaeus
E) Linnaeus and Lamarck

B) Lamarck and Wallace

Evolutionary trees such as this are properly understood by scientists to be
A) theories.
B) hypotheses.
C) laws.
D) dogmas.
E) facts.

B) hypotheses

In a hypothetical environment, fishes called pike-cichlids are visual predators of algae-eating fish (i.e., they locate their prey by sight). If a population of algae-eaters experiences predation pressure from pike-cichlids, which of the following should least likely be observed in the algae-eater population over the course of many generations?
A) Selection for drab coloration of the algae-eaters
B) Selection for nocturnal algae-eaters (active only at night)
C) Selection for larger female algae-eaters, bearing broods composed of more, and larger, young
D) Selection for algae-eaters that become sexually mature at smaller overall body sizes
E) Selection for algae-eaters that are faster swimmers

C) Selection for larger female algae-eaters, bearing broods composed of more, and larger, young

Which statement best describes the evolution of pesticide resistance in a population of insects?
A) Individual members of the population slowly adapt to the presence of the chemical by striving to meet the new challenge.
B) All insects exposed to the insecticide begin to use a formerly silent gene to make a new enzyme that breaks down the insecticide molecules.
C) Insects observe the behavior of other insects that survive pesticide application, and adjust their own behaviors to copy those of the survivors.
D) Offspring of insects that are genetically resistant to the pesticide become more abundant as the susceptible insects die off.

D) Offspring of insects that are genetically resistant to the pesticide become more abundant as the susceptible insects die off.

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) Larger doses of DDT should have been applied.
B) All habitats should have received applications of DDT at about the same time.
C) The frequency of DDT application should have been higher.
D) None of the individual insects should have possessed genomes that made them resistant to DDT.
E) DDT application should have been continual.

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

Some members of a photosynthetic plant species are genetically resistant to an herbicide, while other members of the same species are not resistant to the herbicide. Which combination of events should cause the most effective replacement of the non-herbicide-resistant strain of plants by the resistant strain?
1. The presence of the herbicide in the environment
2. The absence of the herbicide from the environment
3. The maintenance of the proper conditions for one generation
4. The maintenance of the proper conditions for many generations
A) 1 and 3
B) 1 and 4
C) 2 and 3
D) 2 and 4

B) 1 and 4

If 3TC resistance is costly for HIV, then which plot (I—IV) best represents the response of a strain of 3TC-resistant HIV over time, if 3TC administration begins at the time indicated by the arrow?
A) I
B) II
C) III
D) IV

C) III

Of the following anatomical structures, which is homologous to the wing of a bird?
A) Dorsal fin of a shark
B) Hindlimb of a kangaroo
C) Wing of a butterfly
D) Tail fin of a flying fish
E) Flipper of a cetacean

E) Flipper of a cetacean

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 share fewer homologous structures than two more closely related organisms.
C) their chromosomes should be very similar.
D) they shared a common ancestor relatively recently.
E) they should be members of the same genus.

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

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 identifying the bones as being homologous
B) By the principle of convergent evolution
C) By proposing that humans, bats, and dolphins share a common ancestor
D) A and C only
E) A, B, and C

D) A and C only

Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
A) Natural selection cannot account for losses, only for innovations.
B) Natural selection accounts for these losses by the principle of use and disuse.
C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.
D) The ancestors of these organisms experienced harmful mutations that forced them to find new habitats that these species had not previously used.

C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.

Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
A) All organisms require energy.
B) All organisms use essentially the same genetic code.
C) All organisms reproduce.
D) All organisms show heritable variation.
E) All organisms have undergone evolution.

B) All organisms use essentially the same genetic code.

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) The skeletal remains of the organisms depicted by the tree were incomplete (i.e., some bones were missing).
D) Transitional fossils had not been found.
E) Relationships between DNA sequences among the species did not match relationships between skeletal patterns.

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

Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ?
A) The appendix can be surgically removed with no immediate ill effects.
B) The appendix might have been larger in fossil hominids.
C) The appendix has a substantial amount of defensive lymphatic tissue.
D) Individuals with a larger-than-average appendix leave fewer offspring than those with a below-average-sized appendix.
E) In a million years, the human species might completely lack an appendix.

C) The appendix has a substantial amount of defensive lymphatic tissue.

Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution?
A) The two species live at great distance from each other.
B) The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.
C) The sizes of the structures in adult members of both species are similar in size.
D) Both species are well adapted to their particular environments.
E) Both species reproduce sexually.

B) The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are
A) homologous.
B) examples of convergent evolution.
C) adaptations to a common environment.
D) A and C only
E) B and C only

E) B and C only

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that
A) island forms and mainland forms descended from common ancestors.
B) common environments are inhabited by the same organisms.
C) the islands were originally part of the continent.
D) the island forms and mainland forms are converging.
E) island forms and mainland forms have identical gene pools.

A) island forms and mainland forms descended from common ancestors.

Monkeys of South and Central America have prehensile tails, meaning that their tails can be used to grasp objects. The tails of African and Asian monkeys are not prehensile. Which discipline is most likely to provide an evolutionary explanation for how this difference in tails came about?
A) Aerodynamics
B) Biogeography
C) Physiology
D) Biochemistry
E) Botany

B) Biogeography

The theory of evolution is most accurately described as
A) an educated guess about how species originate.
B) one possible explanation, among several scientific alternatives, about how species have come into existence.
C) an opinion that some scientists hold about how living things change over time.
D) an overarching explanation, supported by much evidence, for how populations change over time.
E) an idea about how acquired characteristics are passed on to subsequent generations.

D) an overarching explanation, supported by much evidence, for how populations change over time.

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) Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less suited.
E) Only a fraction of the offspring produced by an individual may survive.

B) Poorly adapted individuals never produce offspring.

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) Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms.
B) Forelimb evolution was adaptive in people and bats, but not in whales.
C) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
D) Genes mutate faster in whales than in humans or bats.
E) Whales are not properly classified as mammals.

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

Which of the following observations helped Darwin shape his concept of descent with modification?
A) Species diversity declines farther from the equator.
B) Fewer species live on islands than on the nearest continents.
C) Birds can be found 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.
E) Earthquakes reshape life by causing mass extinctions.

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

Within a few weeks of treatment with the drug 3TC, a patient's HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained?
A) HIV can change its surface proteins and resist vaccines.
B) The patient must have become reinfected with 3TC-resistant viruses.
C) HIV began making drug-resistant versions of reverse transcriptase in response to the drug.
D) A few drug-resistant viruses were present at the start of treatment, and natural selection increased their frequency.
E) The drug caused the HIV RNA to change.

D) A few drug-resistant viruses were present at the start of treatment, and natural selection increased their frequency.

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.
E) humans and chimpanzees are not closely related.

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

Which of the following pairs of structures is least likely to represent homology?
A) The wings of a bat and the arms of a human
B) The hemoglobin of a baboon and that of a gorilla
C) The mitochondria of a plant and those of an animal
D) The wings of a bird and those of an insect
E) The brain of a cat and that of a dog

D) The wings of a bird and those of an insect

Which gas was least abundant in Earth's early atmosphere, prior to 2 billion years ago?
A) O2
B) CO2
C) CH4
D) H2O
E) NH3

A

In their laboratory simulations of the early Earth, Miller and Urey observed the abiotic synthesis of
A) amino acids.
B) complex organic polymers.
C) DNA.
D) liposomes.
E) genetic systems.

A

Which of the factors below weaken the hypothesis of abiotic synthesis of organic monomers in early Earth's atmosphere?
1. the relatively short time between intense meteor bombardment and appearance of the first life forms
2. the lack of experimental evidence that organic monomers can form by abiotic synthesis
3. uncertainty about which gases comprised early Earth's atmosphere
A) 1
B) 2
C) 3
D) 1 and 3
E) 2 and 3

D

Which of the following has not yet been synthesized in laboratory experiments studying the origin of life?
A) liposomes
B) liposomes with selectively permeable membranes
C) oligopeptides and other oligomers
D) protobionts that use DNA to program protein synthesis
E) amino acids

D

In what way were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth?
A) Only early Earth had water vapor in its atmosphere.
B) Only early Earth was intensely bombarded by large space debris.
C) Only early Earth had an oxidizing atmosphere.
D) Less ultraviolet radiation penetrated Earth's early atmosphere.
E) Earth's early atmosphere had significant quantities of ozone.

B

What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites?
A) They had the same proportion of L and D isomers as Earth does today.
B) The proportion of the amino acids was similar to those produced in the Miller-Urey experiment.
C) There were fewer kinds of amino acids on the chondrites than are found in living organisms today.
D) They were delivered in the form of polypeptides.

B) The proportion of the amino acids was similar to those produced in the Miller-Urey experiment.

Which of the following is the correct sequence of these events in the origin of life?
I. formation of protobionts
II. synthesis of organic monomers
III. synthesis of organic polymers
IV. formation of DNA-based genetic systems
A) I, II, III, IV
B) I, III, II, IV
C) II, III, I, IV
D) IV, III, I, II
E) III, II, I, IV

C

Which is a defining characteristic that all protobionts had in common?
A) the ability to synthesize enzymes
B) a surrounding membrane or membrane-like structure
C) RNA genes
D) a nucleus
E) the ability to replicate RNA

B

Although absolute distinctions between the "most evolved" protobiont and the first living cell are unclear, biologists generally agree that one major difference is that the typical protobiont could not
A) possess a selectively permeable membrane boundary.
B) perform osmosis.
C) grow in size.
D) perform controlled, precise reproduction.
E) absorb compounds from the external environment.

D

The first genes on Earth were probably
A) DNA produced by reverse transcriptase from abiotically produced RNA.
B) DNA molecules whose information was transcribed to RNA and later translated in polypeptides.
C) auto-catalytic RNA molecules.
D) RNA produced by autocatalytic, proteinaceous enzymes.
E) oligopeptides located within protobionts.

C

) RNA molecules can both carry genetic information and be catalytic. This supports the proposal that
A) RNA was the first hereditary information.
B) protobionts had an RNA membrane.
C) RNA could make energy.
D) free nucleotides would not have been necessary ingredients in the synthesis of new RNA molecules.
E) RNA is a polymer of amino acids.

A

What probably accounts for the switch to DNA-based genetic systems during the evolution of life on Earth?
A) DNA is chemically more stable and replicates with fewer errors (mutations) than RNA.
B) Only DNA can replicate during cell division.
C) RNA is too involved with translation of proteins and cannot provide multiple functions.
D) DNA forms the rod-shaped chromosomes necessary for cell division.
E) Replication of RNA occurs too slowly.

A

The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of
A) a snowball Earth.
B) earlier genetic systems than those based on DNA.
C) the abiotic synthesis of organic monomers.
D) the delivery of organic matter to Earth by meteors and comets.
E) the endosymbiotic origin of mitochondria and chloroplasts.

B

Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?
A) How can amino acids, simple sugars, and nucleotides be synthesized abiotically?
B) How can RNA molecules catalyze reactions?
C) How did RNA sequences come to carry the code for amino acid sequences?
D) How could polymers involving lipids and/or proteins form membranes in aqueous environments?
E) How can RNA molecules act as templates for the synthesis of complementary RNA molecules?

C

If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for
I. polynucleotide polymerase with low mismatch error rates.
II. polynucleotide polymerases without proofreading capability.
III. batteries of efficient polynucleotide repair enzymes.
IV. polynucleotide polymerases with proofreading capability.
V. polynucleotide polymerases with high mismatch error rates.
A) I only
B) I and IV
C) I, III, and IV
D) II and V
E) II, III and V

D

If relatively small carbonaceous chondrites from space were a significant source of Earth's original amino acids, then which two of these would have been most important in permitting their organic materials to survive impact with Earth?
I. Carbonaceous chondrites must contain no D-amino acids.
II. Earth's early atmosphere must have had little free oxygen.
III. The chondrites must have arrived on Earth before 4.2 billion years ago.
IV. Earth's early atmosphere must have been dense enough to dramatically slow the chondrites before they impacted.
V. The chondrites must have impacted land, rather than a large body of water.
A) I & II
B) II & III
C) II & IV
D) II & V
E) III & IV

C

If the half-life of carbon-14 is about 5,730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?
A) 1,400
B) 2,800
C) 11,200
D) 16,800
E) 22,400

E

Which measurement would help determine absolute dates by radiometric means?
A) the accumulation of the daughter isotope
B) the loss of parent isotopes
C) the loss of daughter isotopes
D) all three of these
E) only A and B

E

How many half-lives should have elapsed if 6.25% of the parent isotope remains in a fossil at the time of analysis?
A) one
B) two
C) three
D) four
E) five

D

Approximately how far back in time does the fossil record extend?
A) 6,000 years
B) 3,500,000 years
C) 6,000,000 years
D) 3,500,000,000 years
E) 5,000,000,000,000 years

D

Assuming that the rate of sea-floor spreading was constant during the 1-million-year period depicted above, Earth's magnetic field has undergone reversal at an average rate of once every
A) 10,000 years.
B) 25,000 years.
C) 100,000 years.
D) 250,000 years.
E) 1,000,000 years.

D

Earth's current magnetic field is the same as it had been when which sea-floor areas solidified?
I. area B
II. area C
III. area D
IV. area E
A) I only
B) II only
C) I and II
D) I and III
E) II and IV

E

Assuming that the rate of sea-floor spreading was constant during the 1-million-year period depicted above, what should be the approximate age of marine fossils found in undisturbed sedimentary rock immediately overlying the igneous rock at the arrow labeled "II"?
A) 10,000 years
B) 250,000 years
C) 500,000 years
D) 1,000,000 years

C

Argon-40, the daughter isotope of potassium-40, is a gas. Elemental potassium has an atomic mass of about 39. If the submersible robot (which is equipped with a drill that is long enough to get to the igneous rock) ascends from depth too quickly, gases trapped within igneous rock may rapidly expand, fracture the rock, and escape from the sample before it can be dated aboard the floating research vessel. Rock samples can also absorb argon gas. Which of these techniques has the highest chance of providing inaccurate dates of igneous rocks distant from the rift valley, and what type of inaccuracy would it cause?
A) if the date of the rock is determined by comparing the ratio of potassium-40 to potassium-39, underestimation of age
B) if the submersible robot is retrieved from the sea floor at a very slow speed, overestimation of age
C) if the submersible robot is equipped with a decompression chamber for the samples, underestimation of age
D) if the submersible robot keeps the sample in a chamber of pure argon at high pressure, overestimation of age

D

What is true of the fossil record of mammalian origins?
A) It is a good example of punctuated equilibrium.
B) It shows that mammals and birds evolved from the same kind of dinosaur.
C) It includes transitional forms with progressively specialized teeth.
D) It indicates that mammals and dinosaurs did not overlap in geologic time.
E) It includes a series that shows the gradual change of scales into fur.

C

If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (e.g., lava, volcanic ash) nearby, then it should be
A) easy to determine the absolute age of the fossil, because the radioisotopes in the sediments will not have been "reset" by the heat of the igneous rocks.
B) easy to determine the absolute age of the fossil, because the igneous rocks will not have physically obstructed the deposition of sediment of a single age next to the fossil.
C) difficult to determine the absolute age of the fossil, because the "marker fossils" common to igneous rock will be absent.
D) difficult to determine the absolute age of the fossil, because radiometric dating of sedimentary rock is less accurate than that of igneous rock.

D

Let's say that a hypothetical submersible robot was used to collect samples of sedimentary rock from the sea floor along the section illustrated. The robot moved back and forth along the transect, collecting first from site A, then site III, then site B, then site II, and lastly site D. Assuming that sedimentation has occurred at a constant rate along the transect over the past million years, rearrange the sites mentioned above on the basis of the thickness of the sediments overlying the igneous rock, from thickest to thinnest.
A) A, B, II, D, III
B) I, II, III
C) III, II, D, B, A
D) III, A, II, B, D
E) III, D, II, B, A

E

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to
A) make life on land difficult for aerobic organisms.
B) change the atmosphere from oxidizing to reducing.
C) make it easier to maintain reduced molecules.
D) cause iron in ocean water and terrestrial rocks to rust (oxidize).
E) prevent the formation of an ozone layer.

D

Arrange these events from earliest to most recent.
1. emission of lava in what is now Siberia at time of Permian extinctions
2. emission of lava that solidified at the same time as iron-bearing terrestrial rocks began to rust
3. emission of lava that solidified at the same time as rusted iron precipitated from seawater
4. emission of lava in what is now India at time of Cretaceous extinctions
A) 3, 1, 2, 4
B) 3, 2, 1, 4
C) 3, 1, 4, 2
D) 1, 3, 2, 4
E) 1, 2, 3, 4

B

Which free-living cells were the earliest contributors to the formation of Earth's oxidizing atmosphere?
A) cyanobacteria
B) chloroplasts
C) mitochondria
D) seaweeds
E) endosymbionts

Answer: A

Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?
A) the primitive structure of plants
B) meteorites that have struck Earth
C) abiotic laboratory experiments that produced liposomes
D) Liposomes closely resemble prokaryotic cells.
E) The oldest fossilized cells resemble prokaryotes.

E) The oldest fossilized cells resemble prokaryotes.

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
A) 4, 3, 2, 1, 5
B) 4, 1, 2, 3, 5
C) 4, 1, 3, 2, 5
D) 4, 3, 1, 5, 2
E) 3, 4, 1, 2, 5

C

If it were possible to conduct sophisticated microscopic and chemical analyses of microfossils found in 3.2-billion-year-old stromatolites, then within such microfossils, one should be surprised to observe evidence of:
I. double-stranded DNA
II. a nuclear envelope
III. a nucleoid
IV. a nucleolus
V. nucleic acids
A) II only
B) III only
C) II and IV
D) II, III, and IV
E) all five of these

C

Recent evidence indicates that the first major diversification of multicellular eukaryotes may have coincided in time with the
A) origin of prokaryotes.
B) switch to an oxidizing atmosphere.
C) melting that ended the "snowball Earth" period.
D) origin of multicellular organisms.
E) massive eruptions of deep-sea vents.

C

Which of these observations fails to support the endosymbiotic theory for the origin of eukaryotic cells?
A) the existence of structural and molecular differences between the plasma membranes of prokaryotes and the internal membranes of mitochondria and chloroplasts
B) the existence of size differences between the cytosolic ribosomes of eukaryotes and the ribosomes within mitochondria and chloroplasts
C) the existence of size differences between some prokaryotic cells and mitochondria
D) the existence of rRNA sequence differences between the cytosolic ribosomes of eukaryotes and the ribosomes within mitochondria and chloroplasts

A

Which event is nearest in time to the end of the period known as snowball Earth?
A) oxygenation of Earth's seas and atmosphere
B) evolution of mitochondria
C) Cambrian explosion
D) evolution of true multicellularity
E) Permian extinction

C

The snowball Earth hypothesis provides a possible explanation for the
A) diversification of animals during the late Proterozoic.
B) oxygenation of Earth's seas and atmosphere.
C) colonization of land by plants and fungi.
D) origin of O2-releasing photosynthesis.
E) existence of prokaryotes around hydrothermal vents on the ocean floor.

A

If two continental land masses converge and are united, then the collision should cause
A) a net loss of intertidal zone and coastal habitat.
B) the extinction of any species adapted to intertidal and coastal habitats.
C) an overall decrease in the surface area located in the continental interior.
D) a decrease in climatic extremes in the interior of the new super-continent.
E) the maintenance of the previously existing ocean currents and wind patterns.

A

A major evolutionary episode that corresponds in time most closely with the formation of Pangaea was the
A) origin of humans.
B) Cambrian explosion.
C) Permian extinctions.
D) Pleistocene ice ages.
E) Cretaceous extinctions.

C

On the basis of their morphologies, how might Linnaeus have classified the Hawaiian silverswords?
A) He would have placed them all in the same species.
B) He would have classified them the same way that modern botanists do.
C) He would have placed them in more species than modern botanists do.
D) He would have used evolutionary relatedness as the primary criterion for their classification.
E) Both B and D are correct.

C

Anatomically, what was true of Lystrosaurus?
A) Its jaw would have been hinged the same way as the jaws of the early reptiles were hinged.
B) It was a tetrapod.
C) It had thin, moist skin without scales.
D) Its dentition (tooth pattern) was typical of modern mammals.
E) It would have had no temporal fenestra in its skull.

B

Which of Lystrosaurus' features help explain why these organisms fossilized so abundantly?
I. the presence of hard parts, such as tusks
II. its herbivorous diet
III. its persistence across at least two geological eras
IV. its widespread geographic distribution
V. its mixture of reptilian and mammalian features
A) I and III
B) III and V
C) III and V
D) I, III, and IV
E) II, III, IV, and V

D

Which of these is the most likely explanation for the modern-day distribution of dicynodont fossils?
A) There had been two previous super-continents that existed at different times long before the Permian period.
B) The dicynodonts were evenly distributed throughout all of Pangaea.
C) The dicynodonts were distributed more abundantly throughout Gondwanaland than throughout any other land mass.
D) The dicynodonts were able to swim long distances, up to thousands of kilometers.
E) The dicynodonts could survive for periods of months aboard "rafts" of vegetation, which carried them far and wide, but not to the northern hemisphere.

C

The observation that tusks were limited to males in several species, and were apparently not used in food-gathering, is evidence that the tusks probably
A) were used by males during the sex act.
B) served as heat-dissipation structures.
C) are homologous to claws.
D) were insignificant to the survival and/or reproduction of dicynodonts.
E) were maintained as the result of sexual selection.

E

Which of these is the most likely explanation for the existence of dicynodont fossils on modern-day Antarctica?
A) They arrived there aboard "rafts" of vegetation, and quickly adapted to the bitterly cold climate.
B) Earth's polar regions were once so warm (especially immediately after the "snowball Earth period") that reptiles and mammal-like reptiles flourished there.
C) The landmass that is now the Antarctic continent was formerly located at a more-northerly position, and was also united to other landmasses.
D) Dicynodonts originated on the island continent of Antarctica and went extinct as the continent migrated to its current position at the South Pole.

Answer: C

Dicynodonts survived the Permian extinction and, therefore, existed during both the
A) Paleozoic and Mesozoic eras.
B) Proterozoic and Archaean eons.
C) Proterozoic and Phanerozoic eons.
D) Mesozoic and Cenozoic eras.
E) Carboniferous and Permian periods.

Answer: A

There are at least a dozen known species in the extinct genus Lystrosaurus. If each species was suited to a quite different environment, then this relatively large number of species is likely due to
A) sexual selection.
B) adaptive radiation.
C) heterochrony.
D) polyploidy.
E) species selection.

Answer: B

The dicynodonts survived the mass extinction that was most closely correlated in time, if not in cause, with
A) snowball Earth.
B) a large (10 km) meteor striking the Earth.
C) an intense period of sun-spot formation, with subsequent increase in solar radiation.
D) the formation of Pangaea and lava flows that covered large portions of Pangaea.
E) the pleistocene Ice Age.

Answer: D

The dicynodonts that survived the Permian extinction would initially have had to endure (or escape from) the physical effects of __________, and subsequently, the biological effects of __________.
A) warm temperatures, decreased metabolism
B) arid conditions, disease
C) meteorite shock waves, lack of food
D) increased sea level, lack of freshwater
E) volcanic ash in the atmosphere, increased predation

Answer: E

If an increase in dicynodont species diversity (i.e., number of species) occurred soon after the Permian extinction, and if it occurred for the same general reason usually given for the increase in mammalian diversity following the Cretaceous extinction, then it should be attributed to
A) an innovation among the dicynodonts that allowed them to fill brand new niches.
B) the availability of previously occupied niches.
C) the extinction of the dinosaurs (except the birds).
D) the evolution of humans.

B

An organism has a relatively large number of Hox genes in its genome. Which of the following is not true of this organism?
A) It evolved from evolutionary ancestors that had fewer Hox genes.
B) It must have multiple paired appendages along the length of its body.
C) It has the genetic potential to have a relatively complex anatomy.
D) At least some of its Hox genes owe their existence to gene duplication events.
E) Its Hox genes cooperated to produce the positional patterns of this organism as it developed.

B

Bagworm moth caterpillars feed on evergreens and carry a silken case or bag around with them in which they eventually pupate. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. This is a good example of
A) allometric growth.
B) paedomorphosis.
C) sympatric speciation.
D) adaptive radiation.
E) changes in homeotic genes.

B

As rat pups mature, the growth of their snouts and tails outpaces growth of the rest of their bodies, producing the appearance of sexually mature males. It is found that sexually mature female rats prefer to mate with mutant, sexually mature males that possess snouts and tails with juvenile proportions. Which of the following terms is (are) appropriately applied to this situation?
A) sexual selection
B) paedomorphosis
C) allometric growth
D) B and C only
E) A, B, and C

E

A hypothetical mutation in a squirrel population produces organisms with eight legs rather than four. Further, these mutant squirrels survive, successfully invade new habitats, and eventually give rise to a new species. The initial event, giving rise to extra legs, would be a good example of
A) punctuated equilibrium.
B) species selection.
C) habitat selection.
D) changes in homeotic genes.
E) allometry.

Answer: D

The loss of ventral spines by modern freshwater sticklebacks is due to natural selection operating on the phenotypic affects of Pitx1 gene
A) duplication (gain in number).
B) elimination (loss).
C) mutation (change).
D) silencing (loss of expression).
E) up-regulation (increase in expression).

Answer: D

If these fly species lost the ability to fly independently of each other as a result of separate mutation events in each lineage, then the flightless condition in these species could be an example of
A) adaptive radiation.
B) species selection.
C) sexual selection.
D) allometric growth.
E) habitat differentiation.

Answer: B

In each fly species, the entire body segment that gave rise to the original flight wings is missing. The mutation(s) that led to the flightless condition could have
A) duplicated all of the Hox genes in these flies' genomes.
B) altered the nucleotide sequence within a Hox gene.
C) altered the expression of a Hox gene.
D) either A or B
E) either B or C

Answer: E

If the foods preferred by each species are found on different parts of the island, and if the flies mate and lay eggs on their food sources, regardless of the location of the food sources, then the speciation events involving these fly species may have been driven, at least in part, by which of the following?
A) autopolyploidy
B) allopolyploidy
C) species selection
D) genetic drift
E) habitat differentiation

Answer: E

If the males' halteres have species-specific size, shape, color, and use in courtship displays, and if the species' ranges overlap, then the speciation events may have been driven, at least in part, by which of the following?
A) autopolyploidy
B) allopolyploidy
C) species selection
D) sexual selection
E) habitat differentiation

D

Fly species W, found in a certain part of the island, produces fertile offspring with species Y. Species W does not produce fertile offspring with species X or Z. If no other species can hybridize, then species W and Y
A) have genomes that are still similar enough for successful meiosis to occur in hybrid flies.
B) have more genetic similarity with each other than either did with the other two species.
C) may fuse into a single species if their hybrids remain fertile over the course of many generations.
D) A and B only
E) A, B, and C

Answer: E

Which of these fly organs, as they exist in current fly populations, best fits the description of an exaptation?
A) wings
B) balancing organs
C) mouthparts
D) thoraxes
E) walking appendages

Answer: B

The existence of the phenomenon of exaptation is most closely associated with which of the following reasons that natural selection cannot fashion perfect organisms?
A) Natural selection and sexual selection can work at cross-purposes to each other.
B) Evolution is limited by historical constraints.
C) Adaptations are often compromises.
D) Chance events affect the evolutionary history of populations in environments that can change unpredictably.

B) Evolution is limited by historical constraints.

If the complex protein assemblage of the prokaryotic flagellum arose by the same general processes as those of the complex eyes of mollusks (such as squids and octopi), then
A) natural selection cannot account for the rise of the prokaryotic flagellum.
B) ancestral versions of this protein assemblage were either less functional, or had different functions, than modern prokaryotic flagella.
C) scientists should accept the conclusion that neither eyes nor flagella could have arisen by evolution.
D) we can conclude that both of these structures must have arisen through the direct action of an "intelligent designer."
E) Both A and C are true.

B) ancestral versions of this protein assemblage were either less functional, or had different functions, than modern prokaryotic flagella.

If the prokaryotic flagellum developed from assemblages of proteins that originally were not involved with cell motility but with some other function instead, then the modern prokaryotic flagellum is a(n)
A) vestigial organ.
B) adoption.
C) exaptation.
D) homogeneous organ.
E) allometric organ.

C) exaptation

In certain motile prokaryotes, dozens of different proteins comprise the motor that powers the prokaryotic flagellum. The motor has a complicated structure, and its various proteins interact to carry out its function. Based on Darwin's explanation for the existence of human eyes, how would he probably have explained the existence of such motors?
A) Because he could not have explained their existence, he would have used supernatural agents as a temporary explanation until the gap in scientific knowledge had been filled.
B) Because he could not have explained their existence, he would have concluded that the human brain has not (and probably cannot) evolve the capability to solve such complex problems.
C) He would have proposed that these motors were the products of aliens, and had been delivered to Earth by extraterrestrial visitors.
D) He would have proposed that less complicated, but still functional, versions (maybe even with a different function) had existed in ancestral prokaryotes.

D) He would have proposed that less complicated, but still functional, versions (maybe even with a different function) had existed in ancestral prokaryotes.

It has been found that certain proteins of the complex motor that drives bacterial flagella are modified versions of proteins that had previously belonged to plasma membrane pumps. This is evidence in support of the claim that
A) some structures are so complex that natural selection cannot, and will not, explain their origins.
B) the power of natural selection allows it to act in an almost predictive fashion, producing organs that will be needed in future environments.
C) the motors of bacterial flagella were originally synthesized abiotically.
D) natural selection can produce new structures by cobbling together parts of other structures.
E) bacteria that possess flagella must have lost the ability to pump certain chemicals across their plasma membranes.

D) natural selection can produce new structures by cobbling together parts of other structures

An explanation for the evolution of insect wings suggests that wings began as lateral extensions of the body that were used as heat dissipaters for thermoregulation. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. If this hypothesis is correct, insect wings could best be described as
A) adaptations.
B) mutations.
C) exaptations.
D) isolating mechanisms.
E) examples of natural selection's predictive ability.

C) exaptations.

If one organ is an exaptation of another organ, then what must be true of these two organs?
A) They are both vestigial organs.
B) They are homologous organs.
C) They are undergoing convergent evolution.
D) They are found together in the same hybrid species.
E) They have the same function.

B) They are homologous organs.

Many species of snakes lay eggs, but in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth is an example of
A) natural selection.
B) sexual selection.
C) species selection.
D) goal direction in evolution.
E) directed selection.

C) species selection.

In the 5—7 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space. As recently as 30,000 years ago, Homo sapiens coexisted with Homo neanderthalensis. Both species had large brains and advanced intellects. The fact that these traits were common to both species is most easily explained by which of the following?
A) species selection
B) uniformitarianism
C) sexual selection
D) A and B only
E) A, B, and C

A) species selection

The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that
A) a larger volume-to-surface area ratio is beneficial to all mammals.
B) an unseen guiding force is at work.
C) evolution always tends toward increased complexity or increased size.
D) in particular environments, similar adaptations can be beneficial in more than one species.
E) evolution generally progresses toward some predetermined goal.

D) in particular environments, similar adaptations can be beneficial in more than one species.

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers. If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests, this might be evidence supporting the claim that
A) dinosaurs were as fully endothermal (warm-blooded) as modern birds and mammals.
B) their feathers originally served as insulation, and only later became flight surfaces.
C) the earliest reptiles could fly, and the feathers of flightless dinosaurs were vestigial flight surfaces.
D) the feathers were plucked from the bodies of other adults to provide nest-building materials.
E) all fossils with feathers are actually some kind of bird.

B) their feathers originally served as insulation, and only later became flight surfaces.

The appearance of Pax-6 in all animals with eyes can be explained in multiple ways. Based on the information above, which explanation is most likely?
A) Pax-6 in all of these animals is not homologous; it arose independently in many different animal phyla due to intense selective pressure favoring vision.
B) The Pax-6 gene is really not "one" gene. It is many different genes that, over evolutionary time and due to convergence, have come to have a similar nucleotide sequence and function.
C) The Pax-6 gene was an innovation of an ancestral animal of the early Cambrian. Animals with eyes or eyespots are descendants of this ancestor.
D) The perfectly designed Pax-6 gene appeared instantaneously in all animals created to have eyes or eyespots.

C) The Pax-6 gene was an innovation of an ancestral animal of the early Cambrian. Animals with eyes or eyespots are descendants of this ancestor.

Fruit fly eyes are of the compound type, structurally very different from the camera-type eyes of mammals. Even the camera-type eyes of mollusks, such as octopi, are structurally quite different from those of mammals. Yet, fruit flies, octopi, and mammals possess very similar versions of Pax-6. The fact that the same gene helps produce very different types of eyes is most likely due to
A) the few differences in nucleotide sequence among the Pax-6 genes of these organisms.
B) variations in the number of Pax-6 genes among these organisms.
C) the independent evolution of this gene at many different times during animal evolution.
D) differences in the control of Pax-6 expression among these organisms.

D) differences in the control of Pax-6 expression among these organisms.

Pax-6 usually causes the production of a type of light-receptor pigments. In vertebrate eyes, though, a different gene (the rh gene family) is responsible for the light-receptor pigments of the retina. The rh gene, like Pax-6, is ancient. In the marine ragworm, for example, the rh gene causes production of c-opsin, which helps regulate the worm's biological clock. Which of these most likely accounts for vertebrate vision?
A) The Pax-6 gene mutated to become the rh gene among early mammals.
B) During vertebrate evolution, the rh gene for biological clock opsin was co-opted as a gene for visual receptor pigments.
C) In animals more ancient than ragworms, the rh gene(s) coded for visual receptor pigments; in lineages more recent than ragworms, rh has flip-flopped several times between producing biological clock opsins and visual receptor pigments.
D) Pax-6 was lost from the mammalian genome, and replaced by the rh gene much later.

B) During vertebrate evolution, the rh gene for biological clock opsin was co-opted as a gene for visual receptor pigments.

Fossilized stromatolites
A) all date from 2.7 billion years ago.
B) formed around deep-sea vents.
C) resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays.
D) provide evidence that plants moved onto land in the company of fungi around 500 million years ago.
E) contain the first undisputed fossils of eukaryotes and date from 2.1 billion years ago.

C) resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays.

The oxygen revolution changed Earth's environment dramatically. Which of the following adaptations took advantage of the presence of free oxygen in the oceans and atmosphere?
A) the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules
B) the persistence of some animal groups in anaerobic habitats
C) the evolution of photosynthetic pigments that protected early algae from the corrosive effects of oxygen
D) the evolution of chloroplasts after early protists incorporated photosynthetic cyanobacteria
E) the evolution of multicellular eukaryotic colonies from communities of prokaryotes

A) the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules

Select the factor most likely to have caused the animals and plants of India to differ greatly from species in nearby Southeast Asia.
A) The species have become separated by convergent evolution.
B) The climates of the two regions are similar.
C) India is in the process of separating from the rest of Asia.
D) Life in India was wiped out by ancient volcanic eruptions.
E) India was a separate continent until 55 million years ago.

E) India was a separate continent until 55 million years ago.

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.
A) vacant ecological niches
B) genetic drift
C) colonization of an isolated region that contains suitable habitat and few competitor species
D) evolutionary innovation
E) an adaptive radiation in a group of organisms (such as plants) that another group uses as food

B) genetic drift

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped to make possible the evolution of the tetrapod limb. This type of change is illustrative of
A) the influence of environment on development.
B) paedomorphosis.
C) a change in a developmental gene or in its regulation that altered the spatial organization of body parts.
D) heterochrony.
E) gene duplication.

C) a change in a developmental gene or in its regulation that altered the spatial organization of body parts.

Which of the following steps has not yet been accomplished by scientists studying the origin of life?
A) synthesis of small RNA polymers by ribozymes
B) abiotic synthesis of polypeptides
C) formation of molecular aggregates with selectively permeable membranes
D) formation of protobionts that use DNA to direct the polymerization of amino acids
E) abiotic synthesis of organic molecules

D) formation of protobionts that use DNA to direct the polymerization of amino acids

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lungs of an ancestral fish is an example of
A) an evolutionary trend.
B) paedomorphosis.
C) exaptation.
D) adaptive radiation.
E) changes in the Hox gene expression.

C) exaptation.

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