Evolution Test Review

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

Which of the following steps has not yet been accomplished by scientists studying the origin of life?

formation of protocells that use DNA to direct the polymerization of amino acids

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

island forms and mainland forms descended from common ancestors.

The evolutionary effects of genetic drift are greatest when _____.

the population size is small

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

1. Members of a population vary in their heritable traits 2. Although organisms can produce huge numbers of offspring, many of these offspring do not survive.

How many finch species did Darwin send to the British Museum?

13

Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species? 1. allopatric speciation 2. sympatric speciation 3. sexual selection 4. polyploidy

2 and 4

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship.

2 → 4 → 1 → 3

Approximately how far back in time does the fossil record extend?

3.5 billion years

What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses

4, 1, 3, 2, 5

Arrange the following from most general (i.e., most inclusive) to most specific (i.e., least inclusive): 1 natural selection 2. microevolution 3. intrasexual selection 4. evolution 5. sexual selection

4, 2, 1, 5, 3`

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?

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

Which of the following is true?

Current research indicates that medians are not similar to islands when comparing the diversity of animals or plants.

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

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology?

Dogs and wolves shared a common ancestor very recently.

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true?

Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.

If the early history of life on Earth is accurately depicted by the figure, then which statement is least in agreement with the hypothesis proposed by this tree?

Eukaryotes are more closely related to archaeans than to bacteria.

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

You discover that a company illegaly dumped old vats of PCBs into a nearby river. What do you expect to see?

Fish with deformities.

How many of these statements regarding populations are true? 1. Mature males and females of a population can interbreed with each other. 2. Populations are sometimes geographically isolated from other populations. 3. Biological species are made up of populations. 4. Members of a population tend to be genetically more similar to each other than to members of other populations. 5. Populations have genomes, but not gene pools.

Four of these statements are true.

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

The Galápagos Islands are cooled by the _____.

Humboldt Current

Which of the following statements about species, as defined by the biological species concept, is (are) correct? I. Biological species are defined by reproductive isolation. II. Biological species are the model used for grouping extinct forms of life. III. The biological species is the largest unit of population in which successful interbreeding is possible.

I and III

What is true of macroevolution?

It is evolution above the species level.

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 provides the strongest evidence that prokaryotes evolved before eukaryotes?

The oldest fossilized cells resemble prokaryotes.

Which of the following is true?

Once it is established in a population, a new mutation may increase or decrease in frequency depending on the environment.

How were conditions on the early Earth of more than 3 billion years ago different from those on today's Earth?

Only early Earth was intensely bombarded by large space debris.

Hardy-Weinberg equilibrium must occur in populations wherein

Only two of the responses above are correct.

Which of the following is not an observation or inference on which natural selection is based?

Poorly adapted individuals never produce offspring.

Which of the following evolutionary forces results in adaptive changes in allele frequencies?

Selection

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?

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

Which of the following statements about speciation is correct?

Speciation is a basis for understanding macroevolution.

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

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.

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.

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.

A trend toward the decrease in the size of plants on the slopes of mountains as altitudes increase is an example of

a cline

Charles Darwin was the first person to propose

a mechanism for evolution that was supported by evidence.

In a comparison of birds and mammals, having four limbs is

a shared ancestral character.

A hybrid zone is properly defined as

an area where mating occurs between members of two closely related species, producing viable offspring.

Which of the following pairs are the best examples of homologous structures?

bones in the bat wing and bones in the human forelimb

Two animals are considered members of different species if they _____.

cannot mate and produce viable, fertile offspring

In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because

heterozygotes can come about in two ways.

In the formula for determining a populations genotype frequencies, the pq in the term 2pq is necessary because

heterozygotes have two alleles.

You are infected with an antibiotic-resistant strain of Klebsiella pneumoniae. Where did you most likely contract it?

hospital

Natural selection is based on all of the following except

individuals adapt to their environments and, thereby, evolve.

Natural selection ultimately depends on favorable what?

mutations

Concerning growth in genome size over evolutionary time, which of these is least associated with the others?

orthologous genes

The earliest organisms were most likely _____.

prokaryotic

The legless condition that is observed in several groups of extant reptiles is the result of

several instances of the legless condition arising independently of each other.