Biology Exam 4
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?
0.09
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.2. What is the frequency of individuals that are heterozygous for this allele?
0.32
What is the frequency of the A1A2 genotype in a population composed of 20 A1A1 individuals, 80 A1A2 individuals, and 100 A2A2 individuals?
0.4
In peas, a gene controls flower color such that R = purple and r = white. In an isolated pea patch, there are 36 purple-flowering plants and 64 white-flowering plants. Assuming Hardy-Weinberg equilibrium, what is the value of q for this population?
0.80
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?
0.81
How many finch species did Darwin send to the British Museum? 17 30 13 15 21
13
One out of 10,000 babies born in North America is affected by cystic fibrosis, a recessive condition. Assuming that the North American human population is in Hardy-Weinberg equilibrium for this trait, what percentage of the population is heterozygous for this trait? (Remember the equation for a population in Hardy-Weinberg equilibrium: p2 + 2pq + q2 = 1.) 0.01% 0.0001% 2%
2%
Which of the following organisms could be produced by artificial selection? A rabbit that is housebroken. A chimpanzee that communicates through sign language. A cow that produces a large quantity of milk. A dog that serves as the "eyes" for a blind individual.
A cow that produces a large quantity of milk.
You read about soapberry bugs in Chapter 22. Select the correct statement describing relative fitness in these individuals. A soapberry bug with high relative fitness has more mates than other bugs. A soapberry bug with high relative fitness feeds more successfully on fruits than do other bugs. A soapberry bug with high relative fitness has a relatively high number of offspring that survive to reproductive age.
A soapberry bug with high relative fitness has a relatively high number of offspring that survive to reproductive age.
Which term describes a trait that increases an individual's ability to survive in a particular environment? Adaptation Heritability Fitness Evolution
Adaptation
The theory of evolution through natural selection is considered a scientific theory because _____. it is broad enough in scope to explain many observations it is supported by a massive body of evidence from many disciplines it is general enough to provide many testable hypotheses All of the above are correct. None of the above is correct.
All of the above are correct.
The original habitat of the North American maggot fly, Rhagoletis pomonella, was native hawthorn trees. About 200 years ago, some populations colonized newly introduced apple trees. The two populations are still classified as subspecies, but sympatric speciation is under way. What has contributed to incipient speciation in the maggot fly? Maggot flies that feed and lay eggs on apples have gradually become adapted to this fruit. Because apples mature more quickly than hawthorn fruit, the apple-feeding flies have been selected for more rapid development. Apple maggot flies try to avoid mating with hawthorn maggot flies.
Because apples mature more quickly than hawthorn fruit, the apple-feeding flies have been selected for more rapid development.
What happened in the soapberry bug population in central Florida when the bugs began to feed on smaller goldenrain tree fruits? The length of each bug's beak gradually became shorter over time. Bugs developed short beaks, because they needed them to feed on the small fruits. Bugs with shorter beaks had more access to food, allowing them to produce more offspring.
Bugs with shorter beaks had more access to food, allowing them to produce more offspring.
What is the meaning of Darwin's expression "descent with modification"? Descent with modification refers to natural selection. Descent with modification refers to evolutionary change over time. Descent with modification refers to the partial resemblance of offspring to their parents.
Descent with modification refers to evolutionary change over time.
Long necks make it easier for giraffes to reach leaves high on trees, while also making them better fighters in "neck wrestling" contests. In both cases, which kind of selection appears to have made giraffes the long-necked creatures they are today?
Directional selection
Black-bellied seedcrackers have either small beaks (better for eating soft seeds) or large beaks (better for hard seeds). There are no seeds of intermediate hardness; therefore, which kind of selection acts on beak size in seedcrackers?
Disruptive selection
Which type of selection tends to increase genetic variation?
Disruptive selection
Why were the Galápagos Islands so important to Darwin's formulation of natural selection? They are where Darwin did most of his writing. The species found on the Galápagos Islands are also found in Australia. The Galápagos Islands are the only place in the world where finches are found. They provided evidence in support of uniformitarianism. Each island in the Galápagos possessed unique species.
Each island in the Galápagos possessed unique species.
Which of these is a consequence of uniformitarianism? Earth is round, not flat. Populations evolve. Earth is very old. Populations reproduce faster than their food supply. A Creator made Earth.
Earth is very old.
___ can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met.
Evolution
True or false? Heterozygote advantage refers to the tendency for heterozygous individuals to have better fitness than homozygous individuals. This higher fitness results in less genetic variation in the population.
False
Which of the following are basic components of the Hardy-Weinberg model?
Frequencies of two alleles in a gene pool before and after many random matings
Which term describes the ability of a trait to be passed on to offspring? Evolution Adaptation Heritability Fitness
Heritability
The Galápagos Islands are cooled by the _____. Kuroshio Current Equatorial Countercurrent Monsoon Drift Gulf Stream Humboldt Current
Humboldt Current
In Europe, there is a long narrow hybrid zone, shown in red on the map, between the high-altitude habitat of the yellow-bellied toad and the lowland habitat of the fire-bellied toad. Despite this, there is little gene flow between the two species. Select the correct explanation. Hybrids have poor survival and reproduction and thus produce few viable offspring with members of either parent species. Yellow-bellied toads and fire-bellied toads are two different species. Toads mate only with their own kind in order to avoid producing unhealthy hybrid young.
Hybrids have poor survival and reproduction and thus produce few viable offspring with members of either parent species.
How does diploidy help to preserve genetic variation? It fosters the exchange of genes between different populations. It helps individual organisms make a greater contribution to the gene pool of the next generation. It allows the frequency of a recessive allele in a population to be predicted under certain conditions. It allows recessive alleles that may not be favored in the current environment to be preserved in the gene pool by propagation in heterozygotes. It restricts the gene pool by chance events such as floods or other catastrophic events.
It allows recessive alleles that may not be favored in the current environment to be preserved in the gene pool by propagation in heterozygotes.
What is true of microevolution?
It is the kind of evolution that can change the relative abundance of a particular allele in a gene pool over the course of generations.
What is true of microevolution? It is evolution that involves only tiny changes to DNA, such as point mutations, producing only small (if any) changes to phenotype. It is evolution that influences only a small subset of the populations that comprise a species. It is evolution that is restricted to individual organisms. It is evolution that results in the origin of small numbers of new species. It is the kind of evolution that can change the relative abundance of a particular allele in a gene pool over the course of generations.
It is the kind of evolution that can change the relative abundance of a particular allele in a gene pool over the course of generations.
Which of the following is a true statement concerning genetic variation?
It must be present in a population before natural selection can act upon the population.
Darwin's thinking while on the Beagle was greatly influenced by his reading of a book written by _____. Chaucer Shakespeare Bishop Ussher Wallace Lyell
Lyell
Identify the pair of homologous structures. Neither of the above; plants do not have homologous structures. Maple leaf and oak leaf Maple leaf and maple seed
Maple leaf and oak leaf
Which of the following evolutionary forces could create new genetic information in a population?
Mutation
What is true of natural selection?
Mutations occur at random; natural selection can preserve and distribute beneficial mutations.
Which of the following statements about natural selection is true? Natural selection occurs in opposition to evolution. Natural selection favors individuals that reproduce more than others. Natural selection is a process whereby genes are selected randomly for preservation in the next generation. Natural selection can be used by farmers to generate organisms with desirable traits.
Natural selection favors individuals that reproduce more than others.
According to this climatograph, London experiences more precipitation during _____ than during any other month. July January June February October
October
The Galápagos Islands are located _____. in the Arctic off the coast of California off the coast of Brazil Off the coast of Ecuador in the Antarctic
Off the coast of Ecuador
Which of these is an example of temporal isolation? One species performs a specific courtship dance. the other species does not. The average weight of the individuals in one species is 45 kg; in the other species the average is 290 kg. One species is nocturnal, and the other species is not. One is a type of primate, the other is a type of marsupial. One species is found only in New York, the other only in London.
One species is nocturnal, and the other species is not.
You are studying three populations of birds. Population A has ten birds, of which one is brown (a recessive trait) and nine are red. Population B has 100 birds, of which ten are brown. Population C has 30 birds, and three of them are brown. Which population is most likely to be subject to the bottleneck effect?
Population A
You are studying three populations of birds. Population A has ten birds, of which one is brown (a recessive trait) and nine are red. Population B has 100 birds, of which ten are brown. Population C has 30 birds, and three of them are brown. In which population would it be least likely that an accident would significantly alter the frequency of the brown allele?
Population B
Adaptive radiations on archipelagos (island chains) represent some of the best-understood speciation events. Why is an ancestral species more likely to give rise to multiple descendent species on an archipelago than on an equal-sized area of mainland? Populations on nearby islands are more likely to be genetically isolated than populations that are equally close to one another on the mainland. By chance, different species will colonize different islands in a chain. Favorable mutations are more likely to arise on an archipelago as populations try to adapt to conditions on their specific island.
Populations on nearby islands are more likely to be genetically isolated than populations that are equally close to one another on the mainland.
Which of the following evolutionary forces results in adaptive changes in allele frequencies?
Selection
Small Aristelliger lizards have difficulty defending territories, but large lizards are more likely to be preyed upon by owls. Which kind of selection acts on the adult body size of these lizards?
Stabilizing selection
Women often have complications during labor while giving birth to very large babies, whereas very small babies tend to be underdeveloped. Which kind of selection is most likely at work regarding the birth weight of babies?
Stabilizing selection
In 1959, doctors began using the powerful antibiotic methicillin to treat infections of Staphylococcus aureus, but within two years, methicillin-resistant strains of S. aureus (MRSA) appeared. How did the resistant strains of S. aureus emerge? Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common. In response to treatment of Staphylococcus aureus infections with methicillin, bacterial populations gradually began to synthesize cell walls using a protein that was not affected by methicillin. In response to treatment of Staphylococcus aureus infections with methicillin, some bacteria began to synthesize cell walls using a protein that was not affected by methicillin. These bacteria survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common.
Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common.
Select the correct statement describing sympatric speciation. Sympatric speciation has never been observed in nature. Sympatric speciation is always initiated by geographic isolation of two populations. Sympatric speciation can occur in a single generation.
Sympatric speciation can occur in a single generation.
Soapberry bugs use needlelike "beaks" to feed on seeds within the fruits of various plants. Bugs feed most successfully when their beak length matches the size of the fruit on which they are feeding. For 25 years, populations of soapberry bugs in central Florida have been feeding on small goldenrain tree fruits that were introduced to the area, rather than on the larger native balloon vine fruits that serve as food for other soapberry bug populations. Beak lengths of soapberry bugs are variable, but the average beak length is shorter in soapberry bug populations that feed on goldenrain tree fruits than in populations that feed on balloon vine fruits, as shown in the graph. How does natural selection act on beak length in soapberry bug populations? The action of natural selection on beak length in soapberry bug populations varies with the environment. Natural selection increases beak length in soapberry bug populations. Natural selection decreases beak length in soapberry bug populations.
The action of natural selection on beak length in soapberry bug populations varies with the environment.
The fruit fly Drosophila melanogaster has an allele that confers resistance to DDT and similar insecticides. Laboratory strains of D. melanogaster have been established from flies collected in the wild in the 1930s (before the widespread use of insecticides) and the 1960s (after 20 years of DDT use). Lab strains established in the 1930s have no alleles for DDT resistance. In lab strains established in the 1960s, the frequency of the DDT-resistance allele is 37%. Which statement is correct? Alleles for DDT resistance arose by mutation during the period of DDT use because of selection for pesticide resistance. Resistance to DDT evolved in some fruit flies in order to allow them to survive. The evolutionary fitness associated with the heritable trait of DDT resistance changed once DDT use became widespread.
The evolutionary fitness associated with the heritable trait of DDT resistance changed once DDT use became widespread.
What genotype frequencies are expected under Hardy-Weinberg equilibrium for a population with allele frequencies of p = 0.8 and q = 0.2 for a particular gene?
The expected genotype frequencies are 0.64, 0.32, and 0.04 for A1A1, A1A2, and A2A2, respectively.
Which of the following observations led to Darwin's major inferences? Members of a population vary in their heritable traits. Body parts that are not used deteriorate over time. Organisms only go extinct when catastrophes occur. Although organisms can produce huge numbers of offspring, many of these offspring do not survive. The first and fourth answers are correct.
The first and fourth answers are correct. ( Members of a population vary in their heritable traits. Although organisms can produce huge numbers of offspring, many of these offspring do not survive.)
What is the frequency of the A1 allele in a population composed of 20 A1A1 individuals, 80 A1A2 individuals, and 100 A2A2 individuals?
The frequency of the A1 allele is 0.3.
Which of the following statements is not a part of the Hardy-Weinberg principle?
The genotype frequencies in the offspring generation must add up to two.
A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10% are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population? In two generations, all the fish will be mottled. As the mottled fish are eaten, more will be produced to fill the gap. The ratios will not change. There is no way to predict the result. The proportion of mottled fish will increase over time.
The proportion of mottled fish will increase over time.
Varieties of Staphylococcus aureus that are resistant to the drug methicillin _____. developed in response to the use of methicillin already existed in the population before methicillin was developed always have an advantage in every environment were strongly selected for as methicillin became widely used to treat bacterial infections The second and fourth answers are correct.
The second and fourth answers are correct. ( already existed in the population before methicillin was developed, were strongly selected for as methicillin became widely used to treat bacterial infections)
How long does it take new species to form on Earth? millions of years The time required varies considerably. Speciation no longer takes place on Earth.
The time required varies considerably.
Which statement correctly describes the role of chance in evolution? The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an organism's DNA. An allele that increases evolutionary fitness cannot be lost from a population by chance events. Evolutionary change proceeds by an accumulation of changes that occur by chance.
The ultimate source of new alleles is mutation, random changes in the nucleotide sequences of an organism's DNA.
In a bell-shaped curve, the x-axis (horizontal direction) of the graph represents which of the following?
The value of a particular characteristic; characteristics of an organism can include such traits as size and color.
True or false? The Hardy-Weinberg model makes the following assumptions: no selection at the gene in question; no genetic drift; no gene flow; no mutation; random mating.
True
Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin's? Cuvier Lamarck Wallace Lyell Hutton
Wallace
Rabbit ear size tends to decrease as latitude increases. This is an example of _____. genetic drift a cline polymorphism heterozygote advantage artificial selection
a cline
According to the phylogenetic species concept, what is a species? a clone of genetically identical organisms a population that interbreeds and produces fertile offspring a set of organisms with a unique genetic history a population that is physically able to mate even if there are no offspring or the offspring are infertile a population with a distinct fossil record
a set of organisms with a unique genetic history
An adaptation is _____. an individual's attempt to conform to its environment a trait that gives an organism a reproductive advantage in the current environment the cause of natural selection a trait that gives rise to a new species all of the above
a trait that gives an organism a reproductive advantage in the current environment
Which of the following has been shown to cause speciation most rapidly? autopolyploidy sexual selection hybridization differential resource exploitation punctuated equilibrium
autopolyploidy
Two animals are considered members of different species if they _____. are members of different populations live in different habitats are geographically isolated look different cannot mate and produce viable, fertile offspring
cannot mate and produce viable, fertile offspring
In evolutionary terms, an organism's fitness is measured by its _____. genetic variability health mutation rate stability in the face of environmental change contribution to the gene pool of the next generation
contribution to the gene pool of the next generation
His experiences with Fuegians and slavery convinced Darwin that differences among all peoples are primarily _____ differences. cultural cultural and genetic genetic due to height genetic and height-related
cultural
Patagonia is a _____. tropical forest savanna grassland chaparral desert
desert
Blue poppies native to China were grown at a plant-breeding center in California. The plants with the thickest leaves were most likely to survive and reproduce in the drier climate. After several generations, the percentage of thick-leaved plants had increased by 42%. This adaptation of the poppies to their new environment is due to _____.
directional selection
Blue poppies native to China were grown at a plant-breeding center in California. The plants with the thickest leaves were most likely to survive and reproduce in the drier climate. After several generations, the percentage of thick-leaved plants had increased by 42%. This adaptation of the poppies to their new environment is due to _____. stabilizing selection disruptive selection neutral variation directional selection genetic drift
directional selection
A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____. the embryological development of many plants and animals is almost identical the more advanced the animal, the more slowly it develops all animals develop similar embryonic gills embryos of dissimilar organisms, such as sharks and humans, resemble each other mutations have a far more dramatic effect on embryos than on adult organisms
embryos of dissimilar organisms, such as sharks and humans, resemble each other
What situation most likely explains the occasional high frequency of certain inherited disorders among human populations established by a small population?
founder effect
What situation most likely explains the occasional high frequency of certain inherited disorders among human populations established by a small population? mutation nucleotide variability bottleneck effect gene flow founder effect
founder effect
A certain species of salamander was split into two populations by a wide, dry valley, and the populations began to diverge from each other. After a period of time, some members of the two populations began to interbreed in a hybrid zone at the southern end of the valley. Only weak reproductive barriers existed by this time, so the two populations could freely interbreed and re-establish gene flow. This outcome in a hybrid zone is known as _____. reinforcement stability speciation punctuated equilibrium fusion
fusion
What is the most important factor that holds a gene pool together and prevents speciation? hybridization prezygotic barriers gene flow sexual selection behavioral isolation
gene flow
What process is illustrated by this animation?
gene flow
Allele frequencies in a gene pool may shift randomly and by chance. What is this random shift called?
genetic drift
Allele frequencies in a gene pool may shift randomly and by chance. What is this random shift called? directional selection gene flow genetic drift
genetic drift
There are 40 individuals in population 1, all with genotype A1A1, and there are 25 individuals in population 2, all with genotype A2A2. Assume that these populations are located far from each other and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is most likely an example of
genetic drift.
Which of the following is the first step in allopatric speciation? genetic drift formation of a reproductive barrier geographic isolation polyploidy hybridization
geographic isolation
The Argentinean pampas are a type of _____. temperate deciduous forest desert grassland chaparral tropical forest
grassland
Species in hot climates tend to _____ compared to species in cold climates. have less fear of humans have smaller surface-to-volume ratios experience less interspecific competition have larger surface-to-volume ratios be less colorful
have larger surface-to-volume ratios
Generation-to-generation change in the allele frequencies in a population is _____.
microevolution
The original source of all genetic variation is _____.
mutation
The original source of all genetic variation is _____. sexual reproduction recombination natural selection independent assortment mutation
mutation
What is the only evolutionary mechanism that consistently leads to adaptive evolution?
natural selection
What is the only evolutionary mechanism that consistently leads to adaptive evolution? natural selection the bottleneck effect gene flow genetic drift neutral variation
natural selection
What process is illustrated by this animation?
natural selection
At the fossil site at Punta Alta, Darwin found evidence _____. that Brazilian flatworms were a type of slug of extinction of divine creation that the pampas could support large mammals that extinction does not happen
of extinction
From his observations of organisms in the Galapagos islands, Darwin reasoned that _____. the shape of a bird's beak does not affect its ability to survive and reproduce all island species should be similar to each other organisms had adapted to new environments, giving rise to new species the organisms in the Galapagos had been specially created to thrive in that environment none of the above
organisms had adapted to new environments, giving rise to new species
Charles Darwin _____. was the first person to conclude that organisms evolve proposed that unused parts of the body deteriorate eagerly published his theory before it was well-developed was the first to realize that fossils are remains of ancient organisms proposed natural selection as the mechanism of evolution
proposed natural selection as the mechanism of evolution
According to the _____ model, evolution occurs in spurts; species evolve relatively rapidly then remain unchanged for long periods. geographic isolation nondisjunction adaptive radiation gradualist punctuated equilibrium
punctuated equilibrium
According to the Hardy-Weinberg theorem, the frequencies of alleles in a population will remain constant if _____ is the only process that affects the gene pool.
sexual reproduction
According to the Hardy-Weinberg theorem, the frequencies of alleles in a population will remain constant if _____ is the only process that affects the gene pool. mutation sexual reproduction immigration sexual selection genetic drift
sexual reproduction
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more, than this have reduced fitness. Which of the following terms best describes this situation?
stabilizing selection
Sparrows with average-sized wings survive severe storms better than those with longer or shorter wings, illustrating
stabilizing selection.
Sympatric speciation is _____. the process by which most animal species have evolved the appearance of a new species in the same area as the parent population initiated by the appearance of a geographic barrier especially important in the evolution of island species the emergence of many species from a single ancestor
the appearance of a new species in the same area as the parent population
In the Andes, at elevations of 12,000 feet, Darwin collected fossilized marine shells. The existence of marine shells at this altitude provided evidence that _____. the deposit had been gradually uplifted to its present location geologic processes occur at a rapid rate marine organisms can survive at great elevation someone carried them from the oceans and left them on the mountains Earth's surface does not change
the deposit had been gradually uplifted to its present location
Hybrid zones provide an opportunity to investigate _____. the evolution of reproductive isolation punctuated equilibrium polyploidy allopatric speciation mutations
the evolution of reproductive isolation
Which of the following is an example of the pattern of evolution? (Overview) descent with modification heredity natural selection the inheritance of acquired characteristics the fossil record of the evolution of modern cetaceans
the fossil record of the evolution of modern cetaceans
The evolutionary effects of genetic drift are greatest when _____.
the population size is small
The evolutionary effects of genetic drift are greatest when _____. the population size is large the population size is small sexual selection occurs intraspecific competition is intense intraspecific competition is weak
the population size is small