Bio 102 - Chapter 22

Which of the following organisms could be produced by artificial selection?

A cow that produces a large quantity of milk.

What does it mean that organisms have a nearly universal genetic code?

A specific DNA sequence encodes the same information in one species as it would in nearly any other.

Which term describes a trait that increases an individual's ability to survive in a particular environment?

Adaptation

The theory of evolution through natural selection is considered a scientific theory because __________.

All of the listed answers are correct.

Which of the following observations most strongly supports the common origin of all life on Earth?

All organisms use essentially the same genetic code.

Which of the following statements best defines artificial selection?

Artificial selection is a process in which humans decide which plants and/or animals will and will not breed.

The cow Bos primigenius (which is farmed for meat and milk) has a smaller brain and larger eyes than closely related species of wild ungulates. Which of the following statements best describes the process that led to differences between domesticated/farmed cows and their wild relatives?

Artificial selection resulted in changes in the lineage leading to domesticated cows because humans wanted animals with high milk output and high muscle content.

What happened in the soapberry bug population in central Florida when the bugs began to feed on seeds from the goldenrain tree fruits which are much closer to the fruit surface?

Bugs with shorter beaks had more access to food, allowing them to produce more offspring.

If x indicates the location of fossils of two closely related species, then fossils of their most-recent common ancestor are most likely to occur in which stratum?

C

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, a scientist noticed that males with longer hair get more opportunities to mate and that they father more offspring than males with shorter hair. Which of the following possible studies would be the best design for testing if longer hair is an adaptive trait? Assume that hair length is a trait that is inherited.

Capture a group of males with long hair at random, and cut the hair very short in half of the males; then, compare the number of matings of males with their hair left unchanged vs. males with shortened hair.

Which of the following statements best describes Darwin's theory of evolution by natural selection?

Darwin's theory emphasized that populations vary and change over time.

What is the meaning of Darwin's expression "descent with modification"?

Descent with modification refers to evolutionary change over time.

Which of the following statements about evolutionary trees is accurate?

Evolutionary trees are considered evolutionary hypotheses.

Which term describes the ability of a trait to be passed on to offspring?

Heritability

Which of these conditions do NOT occur in populations evolving due to natural selection?

Individuals pass on most traits that they acquire during their lifetime

It has been observed that organisms on many islands are different from, but closely related to, similar forms found on the nearest continent. Which of the following possible conclusions is best derived from this observation?

Island forms are descended from mainland forms.

Which of the following statements is accurate about an organ described as vestigial?

It must be homologous to some feature in an ancestor.

Which pair of chickens should a farmer breed to produce larger chickens?

Large hen, large rooster

Which of the following statements best describes Linnaeus' method of classifying organisms?

Linnaeus grouped organisms into increasingly more inclusive categories.

Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been endothermic (able to generate its own internal heat). Which of the following statements is likely most accurate about Thrinaxodon?

Mammals evolved from a relative of Thrinaxodon.

Identify the pair of homologous structures.

Maple leaf and oak leaf

Which of the following observations led to Darwin's major inferences?

Members of a population vary in their heritable traits. Although organisms can produce huge numbers of offspring, many of these offspring do not survive.

Which of the following statements about natural selection is true?

Natural selection favors individuals that reproduce more than others.

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?

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

Which of the following statements is most consistent with data obtained from the fossil record?

Older strata carry fossils that differ greatly from living organisms.

Which of the following statements best describes evolution?

Populations change genetically from one generation to the next.

Which of the following statements is most accurate in comparing scientific theories and scientific hypotheses?

Scientific theories are supported by, and make sense of, many observations, whereas scientific hypotheses are narrow, testable ideas.

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by a resistant strain (MRSA). How can this best be explained?

Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Which of the following observations helped Darwin shape his concept of descent with modification?

South American temperate plants are more similar to South American tropical plants than to European temperate ones.

Currently, two living elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which of the following statements would be accurate?

Species X and Y share a greater number of homologies with each other than either does with species Z.

Which of the following is an observation or inference on which natural selection is based?

Species produce more offspring than the environment can support.

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.

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.

Members of two different species possess a similar-looking structure that they use in a similar way to perform about the same function. Which of the following observations would suggest that the relationship more likely represents homology than convergent evolution?

The embryological development of the two structures are similar.

Claytonia virginica is a plant with flowers that vary from white, to pale pink, to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink over white flowers, so that Claytonia with pink flowers produce more seeds than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. Given no other information, if the researcher removes all slugs from the study population, what do you predict will most likely happen to the percentage of flower colors in the population over time?

The percentage of pink flowers will increase over time.

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?

The proportion of mottled fish will increase over time.

Varieties of Staphylococcus aureus that are resistant to the drug methicillin __________.

The second and fourth answers are correct.

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is now largely ineffective against many insects. Which of the following possible actions would have had the best chance of preventing this evolution of DDT resistance?

The use of DDT should have been interspersed with the use of other pesticides that have a different mode of action.

Starting from the wild mustard Brassica oleracea, plant breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Which of the following statements is correct with regard to the wild mustard?

There is enough heritable variation in the wild mustard to permit these different varieties.

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would be most likely to happen in environments that lack antibiotics?

These bacteria would be outcompeted and replaced by bacteria that have lost the antibiotic resistance genes.

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; however, after several years, the farmer sees more and more pigweed growing once again in the fields. Which of the following statements best explains the return of pigweed to the farmer's fields?

Triazine-resistant weeds were more likely to survive and reproduce than were non-resistant individuals.

Over long periods of 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?

Under particular circumstances that persisted for long periods, natural selection reduced each of these structures because they presented greater costs than benefits.

Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin's?

Wallace

Currently, two of the living elephant species (X and Y) are placed in the genus Loxodonta, and a third surviving species (Z) is placed in the genus Elephas. Assuming this classification reflects evolutionary relatedness, which of the following is the most accurate evolutionary tree?

Z-X-Y

An adaptation is

a trait that gives an organism a reproductive advantage in the current environment

Which of the following factors would most likely cause an increase in population size of a prey animal?

an improvement in eyesight

Given what we know about evolutionary biology, which of the following places would be the most likely to have the highest number of species that are unique to the area (that is, that had evolved in that place). Assume that the conditions have existed for at least a few million years.

an isolated group of ocean islands

Of the following anatomical structures, which is most homologous to the bones in the wings of a bird?

bones in the flippers of a whale

Darwin used the phrase "descent with modification" to explain which of the following ideas?

both the unity and diversity of life

A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____.

embryos of dissimilar organisms, such as sharks and humans, resemble each other

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of ________.

homology

DNADNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that

humans and chimpanzees share a relatively recent common ancestor.

After a drought in 1977, researchers hypothesized that on the Galapagos Island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of the following events is now most likely to occur to finch beaks on this island?

increased variation in beak size and shape over time

A heritable trait is one that

is determined at least in part by genes passed from parents to offspring.

From his observations of organisms in the Galapagos Islands, Darwin reasoned that __________.

organisms had adapted to new environments, giving rise to new species

Charles Darwin

proposed natural selection as the mechanism of evolution

A biologist observes that a particular plant species is found in a forest but not in a nearby meadow. She hypothesizes that the plants could grow in the meadow but are not found there because their seeds have yet to land in the meadow. Which of the following would be the most appropriate way to scientifically evaluate this hypothesis?

scattering seeds in several areas of the meadow and observing whether they start to grow

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

strata A and B only

Which of the following is an example of the pattern of evolution?

the fossil record of the evolution of modern cetaceans

In this diagram, each fork represents which of the following ideas?

the most recent common ancestor of the subsequent species