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BIOL 112 Exam 1 (Ch.22,23,24) Practice
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Definition of Evolution (Darwin's time): - ✔✔Descent with modification. Definition of Evolution (currently): - ✔✔A change in the genetic composition of a population from generation to generation. Descent with modification: - ✔✔A phrase Darwin used in proposing that Earth's many species are descendants of ancestral species that were different from the present-day species.
- Which of the following statements best describes theories? A) They are nearly the same things as hypotheses. B) They are supported by, and make sense of, many observations. C) They cannot be tested because the described events occurred only once. D) They are predictions of future events. - ✔✔B) They are supported by, and make sense of, many observations.
- 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.
- With what other idea of his time was Cuvier's theory of catastrophism most in conflict? A) gradualism
B) the fixity of species C) island biogeography D) uniformitarianism E) the scala naturae - ✔✔D) uniformitarianism
- What was the prevailing belief 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.
- 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) If the giraffes did not have to compete with each other, longer necks would not have been passed on to the next generation. - ✔✔A) Characteristics acquired during an organism's life are generally not passed on through genes.
- Which of the following is the most accurate summary of Cuvier's consideration of fossils found in the vicinity of Paris? A) extinction of species yes; evolution of new species yes B) extinction of species no; evolution of new species yes C) extinction of species yes; evolution of new species no D) extinction of species no; evolution of new species yes - ✔✔C) extinction of species yes; evolution of new species no
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) Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future. 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.
- Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection?
- Well-adapted individuals leave more offspring than do poorly adapted individuals.
- A change occurs in the environment.
- Genetic frequencies within the population change.
- Poorly adapted individuals have decreased survivorship. - ✔✔ 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 both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true? A) The amount of available food may have increased. B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight. 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) Three of the statements above are correct.
E) Two of the statem - ✔✔E) Two of the statements above are correct.
- 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) Three of the responses are correct. E) Two of the responses are correct. - ✔✔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 Galápagos finches had come from the South American mainland - ✔✔C) struggle for existence
- If Darwin had been aware of genes, and of their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement? A) If natural selection can change one gene's frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones. B) If an individual's somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring. C) If an individual acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will be the result. D) A single mutation in a single gene in a single gamete will, if perpetuated, produce a new species within just two generations. - ✔✔A) If natural selection can change one gene's frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones.
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
- 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.
- If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic- resistance genes, then what should happen in environments from which antibiotics are missing? A) These genes should continue to be maintained in case the antibiotics ever appear. B) These bacteria should be outcompeted and replaced by bacteria that have lost these genes. C) The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present. D) The bacteria should start making and secreting their own antibiotics. - ✔✔B) These bacteria should be outcompeted and replaced by bacteria that have lost these genes.
- Of the following anatomical structures, which is homologous to the bones in the wing of a bird? A) cartilage in the dorsal fin of a shark B) bones in the hind limb of a kangaroo C) chitinous struts in the wing of a butterfly D) bony rays in the tail fin of a flying fish
E) bones in the flipper of a whale - ✔✔E) bones in the flipper of a whale
- 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 structures B) by the principle of convergent evolution C) by proposing that humans, bats, and dolphins share a common ancestor D) Three of the statements above are correct. E) Two of the statements above are correct. - ✔✔E) Two of the statements above are correct.
- 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?
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. - ✔✔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) Three of the responses above are correct. E) Two of the responses above are correct. - ✔✔E) Two of the responses above are correct.
- Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals? A) homologous; homologous B) analogous; homologous C) homologous; analogous D) analogous; analogous - ✔✔C) homologous; analogous
- What must be true of any organ that is described as vestigial? A) It must be analogous to some feature in an ancestor. B) It must be homologous to some feature in an ancestor. C) It must be both homologous and analogous to some feature in an ancestor. D) It need be neither homologous nor analogous to some feature in an ancestor. - ✔✔B) It must be homologous to some feature in an ancestor.
- What is true of pseudogenes? A) They are composed of RNA, rather than DNA. B) They are the same things as introns. C) They are unrelated genes that code for the same gene product. D) They are vestigial genes. - ✔✔D) They are vestigial genes.
- 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.
- If one wanted to find the largest number of endemic species, one should visit which of the following geological features (assuming each has existed for several millions of years)? A) an isolated ocean island in the tropics B) an extensive mountain range C) a midcontinental grassland with extreme climatic conditions D) a shallow estuary on a warm-water coast - ✔✔A) an isolated ocean island in the tropics
- A high degree of endemism is most likely in environments that are A) easily reached and heterogeneous. B) isolated and heterogeneous. C) isolated and homogeneous. D) isolated and extremely cold. E) easily reached and homogeneous. - ✔✔B) isolated and heterogeneous.
C) They should share fewer anatomical homologies - ✔✔B) Their genomes should be more similar to each other than are the genomes of the five tree finch species. About 13 different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the 13 species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza).
- According to a 1999 study, the vegetarian finch is genetically no more similar to the tree finches than it is to the ground finches, despite the fact that it is placed in the same genus as the tree finches. Based on this finding, it is reasonable to conclude that the vegetarian finch A) is no more closely related to the tree finches than it is to the gro - ✔✔A) is no more closely related to the tree finches than it is to the ground finches, despite its classification. About 13 different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the 13 species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza).
- A 14th species that descended from the original ancestral finch, the Cocos Island finch, is endemic to its namesake island, located 550 km off Costa Rica. The Cocos Island finch is genetically much more similar to the tree finches than is the vegetarian finch, yet it is classified in its own genus Pinarolaxias. Moreover, the Cocos Island finch and the veg - ✔✔E) be placed in its own genus.
- 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 well suited.
E) Only a fraction of an individual's offspring may survive. - ✔✔B) Poorly adapted individuals never produce offspring.
- 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 six months of effectively using methicillin to treat S. aureus infections in a community, all new infections were caused by MRSA. How can this result best be explained? A) S. aureus can resist vaccines. B) A patient must have become infected with MRSA from another community. C) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. D) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. E) The drug caused the S. aureus DNA to change. - ✔✔D) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.
- 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.
D) average number of loci - ✔✔A) average heterozygosity
- Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true? A) Each bird evolved a deeper, stronger beak as the drought persisted. B) Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. C) Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. D) The frequency of the strong-beak alleles increased in each bird as the drought persisted. - ✔✔B) Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.
- Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence? A) mutation B) nonrandom mating C) genetic drift D) natural selection E) gene flow - ✔✔C) genetic drift
- In modern terminology, diversity is understood to be a result of genetic variation. Which of the following is a recognized source of variation for evolution? A) mistakes in translation of structural genes B) mistakes in protein folding C) rampant changes to the dictionary of the genetic code D) binary fission E) recombination by crossing over in meiosis - ✔✔E) recombination by crossing over in meiosis
- A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of
A) a cline. B) a bottleneck. C) relative fitness. D) genetic drift. E) geographic variation. - ✔✔A) a cline.
- The higher the proportion of loci that are "fixed" in a population, the lower is that population's A) nucleotide variability only. B) genetic polyploidy only. C) average heterozygosity only. D) nucleotide variability, average heterozygosity, and genetic polyploidy. E) nucleotide variability and average heterozygosity only. - ✔✔E) nucleotide variability and average heterozygosity only.
- Which statement about variation is true? A) All phenotypic variation is the result of genotypic variation. B) All genetic variation produces phenotypic variation. C) All nucleotide variability results in neutral variation. D) All new alleles are the result of nucleotide variability. E) All geographic variation results from the existence of clines. - ✔✔D) All new alleles are the result of nucleotide variability.
- Rank the following one-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide:
- insertion mutation deep within an intron
- substitution mutation at the third position of an exonic codon
- substitution mutation at the second position of an exonic codon
- deletion mutation within the first exon of the gene - ✔✔4, 3, 2, 1
D) Four of these statements are true. E) All five of these statements are true. - ✔✔D) Four of these statements are true.
- Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus A) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change. B) natural selection, gene flow, and genetic drift are acting equally to change an allele's frequency. C) this means that, at this locus, two alleles are present in equal proportions. D) the population itself is not evolving, but individuals within the population may be evolving. - ✔✔A) the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change.
- In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because A) the population is diploid. B) heterozygotes can come about in two ways. C) the population is doubling in number. D) heterozygotes have two alleles. - ✔✔B) heterozygotes can come about in two ways.
- In the formula for determining a population's genotype frequencies, the pq in the term 2pq is necessary because A) the population is diploid. B) heterozygotes can come about in two ways. C) the population is doubling in number. D) heterozygotes have two alleles. - ✔✔D) heterozygotes have two alleles.
- Hardy-Weinberg equilibrium must occur in populations wherein A) an allele remains fixed. B) no genetic variation exists. C) natural selection is not operating.
D) All three of the responses above are correct. E) Only two of the responses above are correct. - ✔✔E) Only two of the responses above are correct.
- In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the percentage of the population that is homozygous for this allele? A) 0. B) 0. C) 0. D) 9. E) 49.0 - ✔✔D) 9.
- In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the percentage of the population that is heterozygous for this allele? A) 0. B) 2. C) 4. D) 16. E) 32.0 - ✔✔E) 32.
- In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.1. What is the frequency of individuals with AA genotype? A) 0. B) 0. C) 0. D) 0. E) Genotype frequency cannot be determined from the information provided. - ✔✔D) 0.
- You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population? A) 0.
