AP Bio Unit 7 Review

Nine percent of a population is homozygous recessive (aa) at a certain locus. Assuming that the population is in Hardy-Weinberg equilibrium, which of the following is closest to the frequency of the recessive allele (a)?

0.30

A particular gene has two alleles, a dominant allele A and a recessive allele a. The frequency of allele A is 0.55. If the population is in Hardy-Weinberg equilibrium with respect to the gene, then what is the expected frequency of genotype Aa?

0.495

One of the oldest known mammalian fossils belongs to a small furry species, Hadrocodium wui, that lived 195 million years ago. For the following 100 million years, only a small number of groups of mammalian fossils are found in the fossil record. By 65 million years ago, the nonavian dinosaurs were extinct. By 55 million years ago, there were 130 mammal genera, including 4000 different species that occupied a wide variety of habitats. Which of the following best describes the cause of the rapid increase in the number of mammalian species between 65 and 55 million years ago?

After the dinosaur extinction, many ecological niches became available, leading to the adaptive radiation of mammals.

The cladogram shows shared traits among four plant taxa. Based on the cladogram, which of the following are the traits shared between ferns and pines

Embryo and xylem only

Experimental evidence shows that the process of glycolysis is present and virtually identical in organisms from all three domains, Archaea, Bacteria, and Eukarya. Which of the following hypotheses could be best supported by this evidence?

Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life.

Which of the following statements best explains how a condition of Hardy-Weinberg equilibrium results in a population that exhibits stable allele frequencies (i.e., a nonevolving population)

In the absence of selection, allele frequencies in a population will not change. (INCORRECT)

The active transport pump used to move sodium ions across the membranes of gill cells in a freshwater fish has each of the following characteristics except

It uses osmosis to carry sodium ions into the cells.

the bird, Parus major, is commonly found in man-made habitats. During the summer these birds primarily feed on insects, and in the winter, when insects are scarce, they forage in gardens and bird feeders for seeds, nuts, and berries. Recently, climate change has led to a decrease in food available from gardens, and scientists have observed that the average beak length of the birds has increased. Which of the following best explains the directional shift in beak length in these birds?

Longer beaks allow the birds to better access seeds in bird feeders.

A scientist used the amino acid sequence of cytochrome c in different species to consider evolutionary relationships. The data below summarize the number of differences in the amino acids sequences of cytochrome c found in selected species. Interpretation of the data supports which of the following statements?

Mammals are more closely related to reptiles than they are to fish.

Researchers observed selected internal structures of four different microscopic organisms as part of a larger study on the divergence between eukaryotes and prokaryotes. Their observations are recorded in figure 1. Which organism would the researchers most likely predict to be most distantly related to eukaryotes?

Organism 1

Figure 1. Beak depth and offspring survival in a species of finch. Based on the data in figure 1, which of the following best describes the concept illustrated?

Parental pairs with a specific beak depth had the highest reproductive fitness.

The hormone prolactin has varying effects in many different animal species. All vertebrates produce prolactin, which is involved in signal transduction pathways. In mammals, prolactin plays an important role in osmoregulation. In birds, prolactin is involved in lipid metabolism. Which of the following best explains the presence of prolactin in various vertebrate species?

Prolactin is a homologous hormone because it has a common origin but different functions in various species.

Which of the following factors is the most effective in changing the allele frequency in a natural population

Selection

Experiment 1 & Experiment 2: Which one of the following statements best justifies the claim that the conditions in at least one of the experiments could generate the molecular building blocks essential for life?

The carbon dioxide (CO2) gas and water (H2O) vapor in experiment 1 could react spontaneously to produce the phospholipids required by the first life-forms. (INCORRECT, prob nitrogen gas an ammonia)

By discharging electric sparks into a laboratory chamber atmosphere that consisted of water vapor, hydrogen gas, methane, and ammonia, Stanley Miller obtained data that showed that a number of organic molecules, including many amino acids, could be synthesized. Miller was attempting to model early Earth conditions as understood in the 1950s. The results of Miller's experiments best support which of the following hypotheses?

The molecules essential to life today could have formed under Earthly conditions.

In a large, isolated population of an insect species, a specific gene locus has one dominant allele (A)(A) and one recessive allele (a)(a). The genotype frequencies of the gene were collected for ten generations, as shown in table 1. Which of the following could best account for the change in genotypic frequencies over the ten generations?

The population is not exhibiting random mating between individuals.

All of the following are examples of prezygotic genetic isolating mechanisms except

The progeny of a cross between two different lizard species fail to develop properly

Two populations of a species of squirrel are geographically isolated from each other. Although they have the same population density, one population is significantly larger in number than the other. A new bacterial disease, which is easily spread and extremely virulent, affects both populations at the same time. Which of the following is the best prediction of how the new disease will affect the two populations?

The smaller population will be more affected than will the larger population, because the smaller population has less genetic variation than the larger population has.

Hemoglobin is a highly conserved protein used by all mammals to transport oxygen. Table 1 was constructed by comparing the amino acid sequence in the hemoglobin molecules from five different mammal species. Which of the following best describes the importance of the number of amino acid differences indicated in Table 1?

They reflect the number of base pair changes in the DNA

Figure 1 illustrates a process that occurs in a certain group of organisms. Which of the following best predicts the importance of this process?

This process is common to all members of Eukarya and allowing noncoding regions of RNA to be removed so that proteins with the correct amino acid sequence are produced.

Th FtsZ protein is present in prokaryotes and in chloroplasts. The protein is structurally and functionally similar to tubulin proteins of eukaryotic cells. Which of the following is a likely conclusion to draw from this information?

Tubulin genes are evolutionarily derived from the gene that codes for the FtsZ protein

Climate change is disrupting the length of winter in various ecosystems, resulting in less snowfall and milder winters. Scientists in Finland have been observing the tawny owl, a fairly large owl species that is commonly found in woodlands across much of Europe and Asia. Typically, the feathers of the upper body are either brown (BB) or gray (bb). Scientists studying tawny owls in Finland have found that the percentage of tawny owls that have brown feathers has increased over the past 28 years. Which of the following best explains why the brown-feathered phenotype in tawny owls has increased over the past 28 years?

With milder winters, the advantage of gray feathers that blend into a snowy environment has decreased.

In plants, members of the euphorbia family and the cactus family have separate origins, with the euphorbia evolving in the desert regions of Asia and Africa and the cacti in the desert regions of the Americas. Both have fleshy stems adapted for water storage, protective spines, and leaves that are greatly reduced or absent. The similarities between these two families of plants represent an example of

convergent evolution

A number of phylogenies (evolutionary trees) have been proposed by scientists. These phylogenies are useful because they can be used to

evaluate which groups of organisms may be most closely related

In a small group of people living in a remote area, there is a high incidence of "blue skin", a condition that results from a variation in the structure of hemoglobin. All of the "blue skinned" residents can trace their ancestry to one couple, who were among the original settlers of this region. The unusually high frequency of "blue skin" in the area is an example of

genetic drift

The wing of a bat, the flipper of a whale, and the forelimb of a horse appear very different, yet detailed studies reveal the presence of the same basic bone pattern. These structures are examples of

homologous structures

In Darwinian terms, the fittest individuals of a species are those that

leave the greatest number of reproducing descendants

For the following group of questions first study the description of the situation and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. A survey reveals that 25 percent of a population of 1,000 individuals have attached earlobes (are homozygous recessive for the trait). For the following questions, assume that the population fits the parameters of the Hardy-Weinberg law. If p equals the frequency of the dominant allele and q equals the frequency of the recessive allele, which of the following terms represents the frequency of the individuals who show the dominant phenotype?

p2+2pq

The condition in which there are barriers to successful interbreeding between individuals of different species in the same community is referred to as

reproductive isolation

Evolutionary fitness is measured by

reproductive success

The placement and development of two bones in the reptilian jaw are very similar to that of two bones of the mammalian middle ear, which probably evolved from the reptile bones. The similarity of these bones is an example of

speciation (INCORRECT, prob convergent evolution)