CH 13-15

29) The recessive allele of a gene causes cystic fibrosis. For this gene among Caucasians, p = 0.98. If a Caucasian population is in Hardy-Weinberg equilibrium with respect to this gene, what proportion of babies is born homozygous recessive and therefore suffers cystic fibrosis? A) (0.02)2 = 0.0004 B) 0.02 C) (0.98)2 = 0.9604 D) 2(0.02 × 0.98)= 0.0392

A) (0.02)2 = 0.0004

15) Which of the following would prevent an organism from becoming part of the fossil record when it dies? A) It is fully decomposed by bacteria and fungi. B) It is buried in fine sediments at the bottom of a lake. C) It gets trapped in sap. D) It is frozen in ice.

A) It is fully decomposed by bacteria and fungi

11) Which of the following assumptions or observations is not part of Darwin's idea of natural selection? A) Whether an organism survives and reproduces is almost entirely a matter of random chance. B) Heritable traits that promote successful reproduction should gradually become more common in a population. C) Populations produce more offspring than their environment can support. D) Organisms compete for limited resources

A) Whether an organism survives and reproduces is almost entirely a matter of random chance.

22) A population is A) a group of individuals of the same species that live in the same area and interbreed. B) all individuals of a species, regardless of location or time period in which they live. C) a group of individuals of different species living in the same place at the same time. D) a group of individuals of a species plus all of the other species with which they interact

A) a group of individuals of the same species that live in the same area and interbreed.

44) Which of the following would most quickly be eliminated by natural selection? A) a harmful allele in an asexual, haploid population B) a harmful recessive allele in a sexual, diploid population C) a harmful recessive allele in a sexual, polyploid population D) any harmful allele, regardless of the system of inheritance in a population

A) a harmful allele in an asexual, haploid population

29) The emergence of many diverse species from a common ancestor is called A) adaptive radiation. B) gradualism. C) allopatric speciation. D) hybridization.

A) adaptive radiation.

39) A rabbit population consists of animals that are either very dark on top or very light on top. The color pattern is not related to sex. No rabbit shows intermediate coloration (medium darkness). This pattern might result from A) disruptive selection. B) directional selection. C) stabilizing selection. D) sexual selection

A) disruptive selection.

33) Thirty people are selected for a long-term mission to colonize a planet many light-years away from Earth. The mission is successful, and the population rapidly grows to several hundred individuals. However, certain genetic diseases are unusually common in this group, and the group's gene pool is quite different from that of the Earth population they have left behind. Which of the following phenomena has left its mark on this population? A) founder effect B) bottleneck effect C) high rates of mutation D) natural selection

A) founder effect

41) Mate-attracting features such as the bright plumage of a male peacock result from A) intersexual selection. B) artificial selection. C) disruptive selection. D) stabilizing selection.

A) intersexual selection.

20) Diane Dodd raised different fruit fly populations on different food sources. She found that after about 40 generations the evolution of reproductive isolation was under way. The mechanism of evolution responsible for this was A) natural selection. B) genetic drift. C) gene flow. D) hybridization

A) natural selection.

5) These data demonstrate an example of A) nonrandom mating. B) genetic drift. C) a population in Hardy-Weinberg equilibrium. D) gene flow between populations.

A) nonrandom mating.

27) Sympatric speciation commonly occurs through ________ in plants but is more likely to occur through ________ in animals. A) polyploidy; habitat differentiation and sexual selection B) habitat differentiation and sexual selection; polyploidy C) asexual reproduction; chromosome duplications D) self-pollination; polyploidy and other genetic mechanisms

A) polyploidy; habitat differentiation and sexual selection

10) Which of the following best expresses the concept of natural selection? A) reproductive success influenced by inherited characteristics B) inheritance of acquired characteristics C) change in response to need D) a process of constant improvement, leading eventually to perfection

A) reproductive success influenced by inherited characteristics

4) Darwin found that many of the species on the Galápagos Islands A) resembled species on the nearest mainland. B) resembled species in Europe. C) resembled species from Australia. D) were identical to South American species.

A) resembled species on the nearest mainland.

23) Speciation without geographic isolation is called ________ speciation. A) sympatric B) allopatric C) incomplete D) diversifying

A) sympatric

7) Which of the following types of reproductive barriers separates a pair of species that could interbreed but for the fact that one mates at dusk and the other at dawn? A) temporal isolation B) habitat isolation C) behavioral isolation D) mechanical isolation

A) temporal isolation

) The variation in gene pools among the 30 pupfish populations occurred through an evolutionary mechanism called A) the bottleneck effect. B) directional selection. C) random mating. D) Hardy-Weinberg equilibrium.

A) the bottleneck effect

55) Which of the following statements about evolutionary adaptation is true? A) An individual who has learned how to survive cold winters has become adapted to the cold. B) A population that has an increase in frequency of alleles for thicker fur has become adapted to the cold. C) Adaptation results when cold temperatures cause mutations for longer fur. D) Adaptation is possible when all the alleles in a gene pool are the same

B) A population that has an increase in frequency of alleles for thicker fur has become adapted to the cold.

30) Which of the following would tend to promote adaptive radiation? A) An organism has a very stable set of features and capabilities over long spans of evolutionary time. B) An organism colonizes an isolated area that is habitable but relatively devoid of life. C) An organism colonizes an area that already has a high level of existing species diversity. D) A single species goes extinct, but it has several competitors that quickly expand to assume its ecological roles.

B) An organism colonizes an isolated area that is habitable but relatively devoid of life.

28) Which of the following statements about the Galápagos finches is false? A) The Galápagos finch species differ in their feeding habitats. B) Each island in the Galápagos chain has one and only one isolated, unique species of Darwin's finch. C) Most speciation events of the Galápagos finches occurred when some finches made it to another island, evolved in isolation, and accumulated enough changes to become a new species. D) The evolution of the Galápagos finches is an excellent example of adaptive radiation

B) Each island in the Galápagos chain has one and only one isolated, unique species of Darwin's finch.

45) The sickle-cell allele produces a serious blood disease in homozygotes. Why doesn't natural selection eliminate this allele from all human populations? A) Natural selection is a positive force, so it does not eliminate alleles. B) In populations where endemic malaria is present, heterozygotes have an important advantage: They are resistant to malaria and therefore are more likely to survive and produce offspring that carry the allele. C) Mutations keep bringing the allele back into circulation. D) Natural selection occurs very slowly, but elimination of the sickle-cell allele is expected to occur soon

B) In populations where endemic malaria is present, heterozygotes have an important advantage: They are resistant to malaria and therefore are more likely to survive and produce offspring that carry the allele.

32) Two bird species overlap in a hybrid zone. They are isolated by a slight difference in the male songs and by the females' tendency to select males with the "correct" song. Hybrid offspring tend to have reduced fertility compared to either of the parent species. What effect might natural selection have in this situation? A) Natural selection might favor males with less distinctive calls and/or females that are less "choosy." B) Natural selection might favor males with more distinctive calls and/or females that are more "choosy." As a result, the reproductive barrier between the two species could be reinforced. C) Natural selection could lead to the hybrid species taking over and eliminating the weaker parent species. D) Natural selection could lead to the stronger of the two species taking over and eliminating the other species.

B) Natural selection might favor males with more distinctive calls and/or females that are more "choosy." As a result, the reproductive barrier between the two species could be reinforced.

14) Which of the following statements regarding natural selection is false? A) Natural selection depends on the local environment at the current time. B) Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness. C) Natural selection and evolutionary change can occur in a short period of time (a few generations). D) Natural selection can be observed working in organisms alive today

B) Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness.

58) A news article discussing the evolution of domestic dogs from wolves included this statement: "On its way from pack-hunting carnivore to fireside companion, dogs learned to love—or at least live on—wheat, rice, barley, corn, and potatoes." What is a more scientifically accurate way to state what happened with dogs? A) Dogs' DNA mutated so that they could eat wheat, rice, barley, corn, and potatoes. B) Some wolves may have had variants in their digestion that allowed them to eat wheat, rice, barley, corn, and potatoes and so were able to survive with humans. C) Being around humans represented an advantage, so wolves were able to take advantage of that by changing their digestion to be able to eat wheat, rice, barley, corn, and potatoes. D) Dogs were created at the same time as wolves.

B) Some wolves may have had variants in their digestion that allowed them to eat wheat, rice, barley, corn, and potatoes and so were able to survive with humans

32) A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a characteristic determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only 10 remain, and those birds all have yellow feathers. Which of the following statements is true? A) Assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds. B) The hurricane has caused a population bottleneck and a loss of genetic diversity. C) This situation illustrates the effect of a mutation event. D) The 10 remaining birds will mate only with each other, and this will contribute to gene flow in the population.

B) The hurricane has caused a population bottleneck and a loss of genetic diversity

54) Brown-eye genes are dominant over blue-eye genes. What is the best explanation for the fact that all the blue-eye alleles have not disappeared in the human population? A) Some blue alleles are always hidden in heterozygotes. B) The population is likely in Hardy-Weinberg equilibrium for that locus. C) Brown-eyed people sometimes have a blue-eyed parent. D) People with brown eyes tend to choose mates with brown eyes, and blue-eyed people tend to choose mates with blue eyes.

B) The population is likely in Hardy-Weinberg equilibrium for that locus.

13) A dog breeder wishes to develop a breed that does not bark. She starts with a diverse mixture of dogs. Generation after generation, she allows only the quietest dogs to breed. After 30 years of work she has a new breed of dog with interesting traits, but on average, the dogs still bark at about the same rate as other dog breeds. Which of the following would be a logical explanation for her failure? A) There is a great deal of variation for the trait (barking). B) The tendency to bark is not a heritable trait. C) The selection was artificial, not natural, so it did not produce evolutionary change. D) Quiet dogs have fewer pups than barkers.

B) The tendency to bark is not a heritable trait.

52) A group of dog breeders is trying to design and develop an ideal dog. They want a dog with a gentle disposition, black fur, long ears, short legs, and a strong sense of smell. Which of the following comments from fellow dog breeders represents the biggest challenge they are likely to face? A) There are breeds with long ears and breeds with short legs, but no breeds with both. B) There does not seem to be any genetic variation in sense of smell. C) Artificial selection is artificial and cannot change the genetics of a breed like natural selection. D) Most dogs with black fur have long legs.

B) There does not seem to be any genetic variation in sense of smell.

48) Some of your DNA may not code for any protein and has no known function in gene regulation; it is sometimes referred to as noncoding DNA. How do nucleotide sequences of "noncoding DNA" evolve? A) They evolve through natural selection. B) They evolve through genetic drift and other chance processes. C) They evolve to be more useful by taking on new functions. D) They evolve by gradually being eliminated from the gene pool.

B) They evolve through genetic drift and other chance processes.

3) If in one population of pupfish all of the individuals have a blood pigment that is extraordinarily effective at carrying oxygen, but this trait is not seen in any of the other populations, what likely happened? A) Because oxygen was low where these pupfish lived, a new allele for an effective blood pigment arose. B) This population was lucky to have an individual with a random mutation for an effective blood pigment, and the frequency of this allele was increased in subsequent generations through natural selection. C) The ancestral population probably had this type of blood pigment, but it was lost through genetic drift in the other 29 populations. D) The other populations did not need this pigment, so they did not evolve it.

B) This population was lucky to have an individual with a random mutation for an effective blood pigment, and the frequency of this allele was increased in subsequent generations through natural selection.

47) Tay-Sachs is inherited as an autosomal recessive allele. Homozygous individuals die within the first few years of life. However, there is some evidence that heterozygous individuals are more resistant to tuberculosis. Which of the following statements about Tay-Sachs is true? A) The allele for Tay-Sachs is always selected against. B) This situation is an example of heterozygote advantage if tuberculosis is present in a population. C) This situation is an example of disruptive selection. D) Heterozygotes will be more fit than either homozygote regardless of environmental conditions.

B) This situation is an example of heterozygote advantage if tuberculosis is present in a population.

12) Which of the following thinkers argued that much of human suffering was the result of human populations increasing faster than food supply, an argument that later influenced Charles Darwin's ideas of natural selection? A) Charles Lyell B) Thomas Malthus C) Godfrey Hardy D) Gregor Mendel

B) Thomas Malthus

18) Uplift and formation of a mountain range divide a freshwater snail species into two isolated populations. Erosion eventually lowers the mountain range and brings the two populations together again, but when they mate, the resulting hybrids all produce sterile young. This scenario is an example of A) sympatric speciation. B) allopatric speciation. C) incomplete speciation. D) diversifying speciation

B) allopatric speciation.

20) What evidence is used to determine the branching sequence of an evolutionary tree? A) experiments in artificial selection B) anatomical or molecular homologous structures C) the number of genes present in an organism D) an overall assessment of general similarities between organisms

B) anatomical or molecular homologous structures

9) Which of the following types of reproductive barriers separates a pair of moth species that could interbreed but for the fact that the females' mating pheromones are not attractive to the males of the other species? A) temporal isolation B) behavioral isolation C) mechanical isolation D) gametic isolation

B) behavioral isolation

15) Frequently, a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate. Such a ritual constitutes a ________ and ________ reproductive barrier. A) mechanical; postzygotic B) behavioral; prezygotic C) temporal; prezygotic D) gametic; postzygotic

B) behavioral; prezygotic

33) In a hybrid zone, ________ can occur if the reproductive barrier between two species is weak, as seen among cichlids in the murky waters of modern Lake Victoria. A) reinforcement B) fusion C) allopatric speciation D) reproductive isolation

B) fusion

8) Which of the following types of reproductive barriers separates a pair of insect species that could interbreed but for the fact that one lives on goldenrod plants and the other on autumn daisies in the same general area? A) temporal isolation B) habitat isolation C) behavioral isolation D) gametic isolation

B) habitat isolation

18) Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of A) geographic similarity. B) homology. C) adaptation by natural selection. D) artificial selection.

B) homology.

40) Large antlers in male elk, which are used for battles between males, are a good example of a trait favored by A) intersexual selection. B) intrasexual selection. C) disruptive selection. D) stabilizing selection.

B) intrasexual selection

27) Which of the following conditions would tend to make the Hardy-Weinberg equation more accurate for predicting the genotype frequencies of future generations in a population of a sexually reproducing species? A) a small population size B) little gene flow with surrounding populations C) a tendency on the part of females to mate with the healthiest males D) mutations that alter the gene pool

B) little gene flow with surrounding populations

46) Frequency-dependent selection, as seen in the case of the scale-eating fish in Lake Tanganyika, tends to A) eliminate rare alleles and favor whichever allele is initially most frequent. B) maintain two phenotypes in a dynamic equilibrium in a population. C) produce random changes in allele frequencies. D) stimulate new mutations.

B) maintain two phenotypes in a dynamic equilibrium in a population

28) Imagine that you are studying a very large population of moths that is isolated from gene flow. A single gene controls wing color. Half of the moths have white-spotted wings (genotype WW or Ww), and half of the moths have plain brown wings (ww). There are no new mutations, individuals mate randomly, and there is no natural selection on wing color. How will p, the frequency of the dominant allele, change over time? A) p will increase; the dominant allele will eventually take over and become most common in the population. B) p will neither increase nor decrease; it will remain more or less constant under the conditions described. C) p will decrease because of genetic drift. D) p will fluctuate rapidly and randomly because of genetic drift.

B) p will neither increase nor decrease; it will remain more or less constant under the conditions described.

5) The frequency of homozygous dominant individuals in a population that is in HardyWeinberg equilibrium is equal to A) q or p. B) p2. C) 2pq. D) 2p.

B) p2.

24) Organisms that possess more than two complete sets of chromosomes are said to be A) haploid. B) polyploid. C) diploid. D) hybrids.

B) polyploid.

13) Two species that sometimes mate and produce vigorous but sterile offspring are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) hybrid breakdown.

B) reduced hybrid fertility.

1) Speciation, or the formation of new species, is A) a form of microevolution. B) responsible for the diversity of life. C) necessary for natural selection and adaptation. D) an event that has occurred only a few times in the history of the planet.

B) responsible for the diversity of life

6) The red throat found in reproductively mature males is likely the result of A) being homozygous. B) sexual selection. C) genetic drift. D) heterozygous advantage

B) sexual selection.

37) An elk herd is observed over many generations. Most of the full-grown bull elk have antlers of nearly the same size, although a few have antlers that are significantly larger or smaller than this average size. The average antler size remains constant over the generations. Which of the following effects probably accounts for this situation? A) directional selection B) stabilizing selection C) a bottleneck effect that resulted in low genetic diversity D) a high rate of gene flow

B) stabilizing selection

16) The Monterey pine and the Bishop's pine inhabit some of the same areas of central California. The Monterey pine releases pollen in February, while the Bishop's pine does so in April. This is an example of ________ isolation. A) postzygotic B) temporal C) habitat D) mechanical

B) temporal

1) Blue-footed boobies have webbed feet and are comically clumsy when they walk on land. Evolutionary scientists view these feet as A) an example of a trait that is poorly adapted. B) the outcome of a trade-off: Webbed feet perform poorly on land but are very helpful in diving for food. C) an example of a trait that has not evolved. D) a curiosity that has little to teach us regarding evolution

B) the outcome of a trade-off: Webbed feet perform poorly on land but are very helpful in diving for food.

19) Which of the following represents a pair of homologous structures? A) the wing of a bat and the scales of a fish B) the wing of a bird and the front legs of a horse C) the antennae of an insect and the eyes of a bird D) the wing of a bat and the wing of a butterfly

B) the wing of a bird and the front legs of a horse

26) Which of the following terms represents the frequency of heterozygotes in a population that is in Hardy-Weinberg equilibrium? A) p B) q C) 2pq D) q2

C) 2pq

53) A farmer decides to go into the business of raising trout for tourists who enjoy fishing. She builds six trout ponds and stocks each of them with trout from genetically identical stock. Her friends tell her that because she started each pond with just a few trout, she has created a bottleneck effect and her trout populations are likely to become genetically different rapidly. Which of the following statements about her trout is likely true? A) Because they are all genetically alike, they will all remain alike even though the ponds are different. B) Because each population started off genetically identical, any mutation that occurs in one pond will also occur in the others. C) Because the ponds are different and the populations are likely to experience different mutations, the populations will likely diverge evolutionarily, but only over many generations. D) The increase in genetic diversity caused by sexual reproduction will promote evolutionary divergence over time.

C) Because the ponds are different and the populations are likely to experience different mutations, the populations will likely diverge evolutionarily, but only over many generations.

49) Mothers and teachers often say they need another pair of eyes on the backs of their heads. And another pair of hands would come in handy in many situations. You can imagine that these traits would have been advantageous to our early hunter-gatherer ancestors as well. According to sound evolutionary reasoning, what is the most likely explanation for why humans do not have these traits? A) Because they actually would not be beneficial to the fitness of individuals who possessed them. Natural selection always produces the most beneficial traits for a particular organism in a particular environment. B) Because every time they have arisen before, the individual mutants bearing these traits have been killed by chance events. Chance and natural selection interact. C) Because these variations have probably never appeared in a healthy human. As tetrapods, we are pretty much stuck with a four-limbed, two-eyed body plan; natural selection can only edit existing variations. D) Because humans are a relatively young species. If we stick around and adapt for long enough, it is inevitable that the required adaptations will arise.

C) Because these variations have probably never appeared in a healthy human. As tetrapods, we are pretty much stuck with a four-limbed, two-eyed body plan; natural selection can only edit existing variations.

7) Which of the following statements would Darwin have disagreed with? A) Species change over time. B) Living species have arisen from earlier life-forms. C) Descent with modification occurs through inheritance of acquired characteristics. D) Descent with modification occurs by natural selection.

C) Descent with modification occurs through inheritance of acquired characteristics.

50) In a large population of plants, notches in the leaves are caused by a dominant allele N and lack of notches by a recessive allele n. Over many generations the proportion of plants in the population with notched leaves increases. What is the most likely cause? A) Dominant alleles generally increase in frequency over time. B) The recessive alleles were all masked by the dominant alleles. C) Directional selection favored plants with notched leaves. D) Genetic drift caused a steady movement toward a greater proportion of plants with notched leaves.

C) Directional selection favored plants with notched leaves.

5) Lyell's book Principles of Geology, which Darwin read on board the HMS Beagle, argued in favor of which of the following concepts? A) Earth's surface is shaped mainly by occasional catastrophic events. B) Meteorite impacts may have been a major cause of periodic mass extinctions. C) Earth's surface is shaped by natural forces that act gradually and are still acting. D) The processes that shape Earth today are very different from those that were at work in the past.

C) Earth's surface is shaped by natural forces that act gradually and are still acting

2) The core theme of biology, which explains both the unity and diversity of life, is A) genetics. B) ecology. C) evolution. D) metabolism.

C) Evolution

57) Which of the following statements regarding fins on fishes is true? A) Fins evolved so that fish could swim better. B) Fins came about because animals couldn't live in water without them. C) Fins are an adaptation that aid in swimming. D) Fins resulted from a mutation caused by a movement from land to water

C) Fins are an adaptation that aid in swimming.

4) The data in the accompanying table are from an experiment seeking to determine why some male fish attract more females than others. A scientist scored females' preference for particular males from 0 (low) to 3 (high), the number of zig-zag courtship dances the males did for each female, and the intensity of the color of the male's throat, a trait that generally indicates sexual maturity. Which hypothesis is supported by the data in the table? A) Females prefer males that spend little time in courtship. B) Male fish spend less than a minute courting females that do show a preference toward them. C) Males generally spend more time courting females that show an interest in them (demonstrate a preference). D) The redness of a male's throat predicts how much a female is likely to prefer him

C) Males generally spend more time courting females that show an interest in them (demonstrate a preference).

8) During the 1950s, a scientist named Lysenko tried to solve the food shortages in the Soviet Union by breeding wheat that could grow in Siberia. He theorized that if individual wheat plants were exposed to cold, they would develop additional cold tolerance and pass it to their offspring. Based on the ideas of artificial and natural selection, do you think this project worked as planned? A) Yes; the wheat probably evolved better cold tolerance over time through inheritance of characteristics the individuals gained during their lifetime. B) No, because Lysenko took his wheat seeds straight to Siberia instead of exposing them incrementally to cold. C) No, because there was no process of selection based on inherited traits. Lysenko assumed that exposure could induce a plant to develop additional cold tolerance and that this tolerance would be passed to the plant's offspring. D) Yes, because this is generally the method used by plant breeders to develop new crops.

C) No, because there was no process of selection based on inherited traits. Lysenko assumed that exposure could induce a plant to develop additional cold tolerance and that this tolerance would be passed to the plant's offspring.

1) Which of the following statements represents a probable explanation for differences among pupfish populations? A) The frequency of genotypes reached equilibrium. B) New genes entered the population through migration. C) The isolated populations had restricted gene pools. D) Each new species contains all the original genotypes of the larger populations.

C) The isolated populations had restricted gene pools.

5) Which of the following statements regarding the definition of species is false? A) The ecological species concept identifies species in terms of their ecological niches. B) The phylogenetic species concept defines a species as a set of organisms that shares a common ancestor and forms one branch on the tree of life. C) The morphological species concept relies upon comparing the DNA sequences of organisms. D) Under the biological species concept, the gap between species is maintained by reproductive isolation.

C) The morphological species concept relies upon comparing the DNA sequences of organisms.

3) The change in curves in the graph represents A) a decrease in genetic variation in a population of mice. B) the appearance of a new allele for darker color in a population of mice. C) a shift in the range of genetic variation in a population of mice. D) a lack of genetic variation for light fur color in the original population of mice

C) a shift in the range of genetic variation in a population of mice.

17) The geographic isolation of a population from other members of the species and the subsequent evolution of reproductive barriers between it and the parent species describes ________ speciation. A) punctuated B) sympatric C) allopatric D) biogeographic

C) allopatric

2) Which statement best describes the mode of selection depicted in the figure?

C) directional selection, changing the average color of the population over time

38) After a copper smelter begins operation, local downwind populations of plants begin to adapt to the resulting air pollution. Scientists document, for example, that the acid tolerance of several plant species has increased significantly in the polluted area. This is an example of A) stabilizing selection. B) disruptive selection. C) directional selection. D) genetic drift.

C) directional selection.

21) Darwin was the first person to draw an evolutionary tree, a diagram that represents A) records of breeding in domesticated animals. B) records of lineages in humans (also known as a family tree). C) evidence-based hypotheses regarding our understanding of patterns of evolutionary descent. D) groupings of organisms based on overall similarity.

C) evidence-based hypotheses regarding our understanding of patterns of evolutionary descent

21) Diane Dodd's experiments using fruit flies demonstrated that A) the evolution of reproductive barriers occurs much too slowly to produce measurable effects in the laboratory. B) new species can form in a single generation by the production of new reproductive structures. C) formation of a reproductive barrier between two populations is more likely if they experience and adapt to different environmental conditions. D) reproductive barriers usually are absolute: Either two populations are fully willing and able to interbreed, or they are strictly separated by a fully effective reproductive barrier.

C) formation of a reproductive barrier between two populations is more likely if they experience and adapt to different environmental conditions.

17) Which of the following disciplines has found evidence for evolution based on the native distributions (locations) of living species? A) molecular biology B) comparative anatomy C) geographic distribution D) paleontology

C) geographic distribution

10) Which of the following types of reproductive barriers separates two flowering plant species that could interbreed but for the fact that one has a deep flower tube and is pollinated by bumblebees whereas the other has a short, narrow flower tube and is pollinated by honeybees? A) habitat isolation B) behavioral isolation C) mechanical isolation D) gametic isolation

C) mechanical isolation

36) Which of the following will tend to produce adaptive changes in populations? A) genetic drift B) gene flow C) natural selection D) the founder effect

C) natural selection

12) Two species that occasionally mate and produce zygotes, but that have incompatible genes that prevent the resulting embryo from developing, are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) behavioral isolation

C) reduced hybrid viability.

3) Aristotle believed that A) species evolve through natural selection and other mechanisms. B) an individual's use of a body part causes it to further evolve. C) species are fixed (permanent) and perfect. D) the best evidence for change within species is seen in fossils

C) species are fixed (permanent) and perfect.

30) Genetic drift resulting from a disaster that drastically reduces population size is called A) natural selection. B) gene flow. C) the bottleneck effect. D) the founder effect.

C) the bottleneck effect

56) Some butterflies can ingest toxic chemicals from the milkweed plants they feed on and then can store those chemicals in their body. Because toxins stored in the butterflies are toxic to birds, the birds avoid eating the butterflies. Which of the following is the best explanation for this situation? A) Butterflies that stored the chemicals were never eaten by predators, so those butterflies survived. B) Butterflies developed a mutation that led them to be able to store the chemical because they needed to avoid being eaten. C) Milkweed plants wanted the butterflies to ingest the chemical so they would no longer feed on the plant, but the butterflies fooled the milkweed by storing the toxic chemicals. D) Any butterfly allele that allowed milkweed toxin storage would be likely to persist because butterflies that had it were more likely to survive.

D) Any butterfly allele that allowed milkweed toxin storage would be likely to persist because butterflies that had it were more likely to survive.

35) Which of the following statements best describes the true nature of natural selection? A) Only the strongest survive. B) The strong eliminate the weak in the race for survival. C) Organisms change by random chance. D) Heritable traits that promote reproduction become more frequent in a population from one generation to the next.

D) Heritable traits that promote reproduction become more frequent in a population from one generation to the next.

19) In which of the following situations would speciation be most likely to occur? A) A population of juniper shrubs is split in two by a canyon. Every year, strong winds carry a small amount of the shrubs' pollen across the canyon. B) A Japanese mollusk species whose larvae are often carried from port to port in ship bilge (waste) water now flourishes in San Francisco Bay, a busy commercial port. C) Bighorn sheep occupy mountains from Canada to Death Valley in Southern California, interbreeding all the way. The populations at the two ends of the range live in very different environments. D) Seven monkeys escape from an enclosure. To everyone's surprise, they establish a small but viable population, coexisting successfully with humans in a partly suburban environment very different from their native African habitat.

D) Seven monkeys escape from an enclosure. To everyone's surprise, they establish a small but viable population, coexisting successfully with humans in a partly suburban environment very different from their native African habitat.

42) A woman struggling with a bacterial illness is prescribed a month's supply of a potent antibiotic. She takes the antibiotic for about two weeks and feels much better. Should she save the remaining two-week supply, or should she continue taking the drug? A) She should save the drug for later, because if she keeps taking it the bacteria will evolve resistance. B) She should save the drug for use the next time the illness strikes. C) She should save the drug because antibiotics are in short supply, and she may need it to defend herself against a bioterrorism incident. D) She should continue taking the drug until her immune system can completely eliminate the infection. Otherwise, some bacteria may remain in her system, and they will probably be resistant.

D) She should continue taking the drug until her immune system can completely eliminate the infection. Otherwise, some bacteria may remain in her system, and they will probably be resistant.

16) Which of the following statements regarding the currently available fossil record is false? A) The currently available fossil record shows that the earliest fossils of life are about 3.5 billion years old. B) The currently available fossil record shows that younger strata were laid down on top of older strata. C) The currently available fossil record documents gradual evolutionary changes that link one group of organisms to another. D) The currently available fossil record shows that the first life-forms were eukaryotes

D) The currently available fossil record shows that the first life-forms were eukaryotes

31) A group of ants escaped from a picnic basket carried to the top of a mountain and thrived in this area where there were no other ants. Many years later descendants of these ants crawled into a picnic basket on the mountain and traveled back to the valley from which their ancestors had come. Which of these observations would cause you to conclude that the ants on top of the mountain had become a different species from those in the valley? A) The mountain ants and valley ants were different colors. B) The mountain ants and valley ants were different sizes. C) The mountain ants ate different food than the valley ants. D) The mountain ants could not mate with the valley ants.

D) The mountain ants could not mate with the valley ants.

51) A population of butterflies has an allele B for big spots on the wings and b for small spots on the wings. The table below provides data about this population. A) The population is in Hardy-Weinberg equilibrium because the number of B alleles is equal to the number of b alleles. B) The population is in Hardy-Weinberg equilibrium because half of the heterozygotes are B and half are b. C) The population is not in Hardy-Weinberg equilibrium because p2 and 2pq are different. D) The population is not in Hardy-Weinberg equilibrium because the genotype frequency of bb is greater than it would be in equilibrium.

D) The population is not in Hardy-Weinberg equilibrium because the genotype frequency of bb is greater than it would be in equilibrium.

2) Which of the following would a biologist describe as microevolution? A) the formation of new species B) the extinction of species C) dramatic biological changes, such as the origin of flight, within a taxon D) a change in the gene pool of a population from one generation to the next

D) a change in the gene pool of a population from one generation to the next

23) Microevolution, or evolution at its smallest scale, occurs when A) an individual's traits change in response to environmental factors. B) a community of organisms changes due to the extinction of several dominant species. C) a new species arises from an existing species. D) a population's allele frequencies change over a span of generations.

D) a population's allele frequencies change over a span of generations.

6) Two populations of organisms belong to the same biological species when they A) cannot mate with each other because mating occurs at different times. B) use different types of behaviors or physical features to attract mates. C) have anatomical features that make it difficult for organisms from the two populations to mate with one another. D) encounter each other, mate, and produce viable, fertile offspring under natural conditions.

D) encounter each other, mate, and produce viable, fertile offspring under natural conditions.

11) Which of the following types of reproductive barriers separates two species of sea cucumbers whose sperm and eggs often bump into each other but do not cross-fertilize because of incompatible proteins on their surfaces? A) temporal isolation B) habitat isolation C) mechanical isolation D) gametic isolation

D) gametic isolation

31) In populations of the greater prairie chicken in Illinois, genetic diversity was lost through A) mutation and restored by natural selection. B) genetic drift and restored by natural selection. C) gene flow and restored by mutation. D) genetic drift and restored by gene flow

D) genetic drift and restored by gene flow

3) Under the biological species concept, a species is a group of organisms that A) are physically similar. B) share a recent common ancestor. C) live together in a location and carry out identical ecological roles. D) have the potential to interbreed in nature and produce fertile offspring

D) have the potential to interbreed in nature and produce fertile offspring

14) Two species interbreed occasionally and produce vigorous, fertile hybrids. When the hybrids breed with each other or with either parent species, however, the offspring are feeble or sterile. These species are affected by A) gametic isolation. B) reduced hybrid fertility. C) reduced hybrid viability. D) hybrid breakdown.

D) hybrid breakdown.

1) According to this figure, which pair of organisms shares the most recent common ancestor

D) lizards and ostriches

22) When plants undergo allopatric speciation, an initial reproductive barrier is often A) polyploidy. B) gametic isolation. C) temporal isolation. D) pollinator choice.

D) pollinator choice.

43) If you were just diagnosed with a serious bacterial disease, which of these would predict the most positive outcome for treatment? The disease was acquired in a A) hospital, where most of the bacteria are probably already weakened by antibiotics in the environment. B) livestock barn where the animals have been treated with antibiotics. C) big city where antibiotics are routinely prescribed by doctors. D) remote, sparsely populated area where the bacteria have not been exposed to antibiotic drugs.

D) remote, sparsely populated area where the bacteria have not been exposed to antibiotic drugs.

4) The biological species concept is A) applicable to all forms of life, past and present. B) applicable to all present life-forms but not to fossil organisms whose reproductive behavior cannot be observed. C) easy to apply to all present sexually reproducing organisms but harder to apply to asexual organisms and fossils. D) sometimes difficult to put into practice even for present sexual organisms and useless for asexual organisms and fossils.

D) sometimes difficult to put into practice even for present sexual organisms and useless for asexual organisms and fossils.

25) Most polyploid species arise from A) a single diploid parent plant. B) a single triploid parent plant. C) a single tetraploid parent plant. D) the hybridization of two parent species

D) the hybridization of two parent species

26) When a tetraploid flower pollinates a diploid flower of the parental species, the resulting offspring will be A) pentaploid and sterile. B) diploid and fertile. C) triploid and fertile. D) triploid and sterile

D) triploid and sterile

9) Broccoli, cabbages, and Brussels sprouts all descend from the same wild mustard and can still interbreed. These varieties were produced by A) artificial selection. B) natural selection. C) genetic drift. D) inheritance of acquired characteristics.

a) artificial selection

34) Genetic differences between populations tend to be reduced by A) gene flow. B) mutation. C) the founder effect. D) natural selection

a) gene flow

24) The ultimate source of all new alleles is A) mutation. B) chromosomal duplication. C) genetic drift. D) natural selection.

a) mutation

6) Who developed a theory of evolution almost identical to Darwin's? A) Lyell B) Wallace C) Aristotle D) Malthus

b) Wallace