1st test

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? A B C All of the above.

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? A B C All of the above

B

Which stratum should contain the greatest proportion of extinct organisms? a b c d

a

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? a. 0.09 b. 0.49 c. 0.75 d. 0.9

a. 0.09

Which of these variables is likely to undergo the largest change in value as the result of a mutation that introduces a brand-new allele into a population's gene pool at a locus that had formerly been fixed? a. Average heterozygosity b. Genetic Drift c. Geographic variability d. Average number of loci

a. Average heterozygosity

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. Disuse of an organ may lead to its eventual disappearance. c. Overproduction of offspring leads to a struggle for survival. d. Spontaneous mutations can result in the appearance of new traits.

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

What was the prevailing notion 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 are unchanging. d. Earth is millions of years old, and populations gradually change.

a. Earth is a few thousand years old, and populations are unchanging.

The table shows the changes in allele frequencies of a specific gene in two populations of randomly mating small mammals after 30 years. The populations inhabit adjacent equatorial islands that have similar topography and climate. Which of the following is the most reliable conclusion that can be drawn from analysis of the data above? a. Genetic drift has occurred in population 1. b. Population 2 is in Hardy-Weinberg equilibrium. c. Selection for allele r is occurring in both populations. d. The reduced frequency of allele R in population 1 will eventually lead to the extinction of population

a. Genetic drift has occurred in population 1.

Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct? a. In this wild mustard, there is enough heritable variation to permit these different varieties. b. Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics. c. Natural selection is rare in wild populations of wild mustard. d. In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.

a. In this wild mustard, there is enough heritable variation to permit these different varieties.

Which happened first during the evolution of cetaceans (marine mammals)? a. changes in hind limb structure b. development of a dorsal fin c. addition of tail flukes (widened area at the tip for propulsion) d. changes in snout formation

a. changes in hind limb structure

A type of isolation in which two populations become separated by a physical barrier such as a canyon, river, lake, preventing the two populations from interbreeding a. geographical isolation b. behavioral isolation c. temporal isolation

a. geographical isolation

Albert's squirrel and the Kaibab squirrel are distinct subspecies that live on opposite sides of the Grand Canyon. They were once one species, but now differ significantly, including fur coloring. a. geographical isolation b. behavioral isolation c. temporal isolation

a. geographical isolation

Tradescantia ohiensis, a plant also known as a bluejacket and it's relative, T. subaspera have similar reproductive mechanisms but do not mate, as one species lives in sun while other lives in shade a. geographical isolation b. behavioral isolation c. temporal isolation

a. geographical isolation

Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this? a. stabilizing selection b. sexual selection c. directional selection d. disruptive selection

a. stabilizing selection

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 49 percent of the animals display a recessive trait (bb), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What proportion of the population is heterozygous (Bb) for this trait? a. 0.51 b. 0.42 c. 0.21 d. 0.09 e. 0.07

b. 0.42

A moth's color is controlled by two alleles, G and g, at a single locus. G (gray) is dominant to g (white). A large population of moths was studied, and the frequency of the G allele in the population over time was documented, as shown in the figure below. In 1980 a random sample of 2,000 pupae was collected and moths were allowed to emerge. Assuming that the population was in Hardy-Weinberg equilibrium for the G locus, what percentage of moths in the natural population was white in 1962 ? a. 2% b. 4% c. 8% d. 20% e. 64%

b. 4%

Poaching is the illegal hunting or capturing of wild animals. Both male and female African elephants have tusks that are a significant source of ivory used for ornaments and jewelry. Assuming that the size of the tusks is heritable, which of the following is the most likely long-term effect of poachers targeting African elephants with large tusks? a. An increase in average tusk size because of the need to provide more ivory for the poaching hunters b. A decrease in average tusk size because elephants with large tusks are less likely to survive to reproduce c. An increase in average tusk size to provide the elephants with a defensive mechanism against poachers d. A decrease in average tusk size to reduce the energy investment in the tusks

b. A decrease in average tusk size because elephants with large tusks are less likely to survive to reproduce

Within six months of effectively treating S. aureus skin infections using the antibiotic methicillin in a community, all new infections were caused by MRSA (methicillin resistant S. aureus). How can this result be explained? a. A patient must have become infected with MRSA from another community. b. A few S. aureus bacterial cells possessed a drug resistant gene were present at the start of the treatment, and natural selection increased their frequency. c. The drug caused the DNA of S. aureus to mutate. d. In response to the drug S. aureus began making drug resistant versions of the protein targeted by the drug.

b. A few S. aureus bacterial cells possessed a drug resistant gene were present at the start of the treatment, and natural selection increased their frequency.

Which of these conditions should completely prevent the occurrence of natural selection in a population over time? a. The environment is changing at a relatively slow rate. b. All variation between individuals is due only to environmental factors and is not heritable. c. The population size is large. d. The population lives in a habitat where there are no competing species present.

b. All variation between individuals is due only to environmental factors and is not heritable.

Ciprofloxacin is given as an antibiotic to healthy livestock to promote efficient weight gain. Strains of the bacterium Campylobacter jejuni naturally colonize the digestive tracts of livestock, and the C. jejuni can be transferred to people through the handling and consumption of contaminated meat. People infected with C. jejuni also are treated with ciprofloxacin. Which of the following is the most likely consequence of adding ciprofloxacin to animal feed? a. Naturally occurring strains of C. jejuni will reproduce more rapidly in the digestive tracts of livestock, reducing the risk of food-borne illnesses in people. b. Ciprofloxacin-resistant strains of C. jejuni will have a selective advantage in the digestive tracts of livestock, increasing the risk of serious infections in people. c. Ciprofloxacin-sensitive strains of C. jejuni will be consumed in meat that contains a chemical that inhibits bacterial growth, reducing the risk of food poisoning in people. d. Actively growing strains of C. jejuni will metabolize the nutrients in meat produced by livestock operations, increasing the risk of protein deficiencies in people.

b. Ciprofloxacin-resistant strains of C. jejuni will have a selective advantage in the digestive tracts of livestock, increasing the risk of serious infections in people.

Anopheles mosquitoes, which carry the malaria parasite, cannot live above elevations of 5900 feet. In addition, oxygen availability decreases with higher altitude. Consider a hypothetical human population that is adapted to life on the slopes of Mt. Kilimanjaro in Tanzania, a country in equatorial Africa. Mt. Kilimanjaro's base is about 2600 feet above sea level and its peak is 19,341 feet above sea level. If the incidence of the sickle-cell allele in the population is plotted against altitude (feet above sea level), which of the following distributions is most likely, assuming little migration of people up or down the mountain? a. Diagram A b. Diagram B c. Diagram C d. Diagram D

b. Diagram B

Pesticides are chemicals that are often sprayed on crops to kill plant-eating insects, preventing damage to the crops. While pesticides are effective initially, many researchers claim that any single pesticide will see reduced effectiveness in as little as ten to fifteen years. Which of the following best supports the claim by scientists that the pesticides will eventually lose their effectiveness? a. Insects will evolve to avoid any plant sprayed with pesticides to increase their chances of survival. b. Insects that are naturally resistant to the pesticide will survive and reproduce more than the insects that are sensitive to the pesticide. c. The insects will build up a tolerance to the pesticides, and eventually the pesticide will not affect them. d. The pesticides will increase the mutation rate in the insects, resulting in higher genetic diversity and higher survival rate.

b. Insects that are naturally resistant to the pesticide will survive and reproduce more than the insects that are sensitive to the pesticide.

In a species of cactus, the number of spines on a plant is genetically determined. The graph above shows frequency distributions for populations of the cactus species growing in the presence or absence of two herbivores: peccaries (a New World pig) and wasp larvae. Which of the following best accounts for the different frequency distributions in the graph? a. Peccaries eat cacti with the greatest number of spines, and wasp larvae show no preference with respect to spine number. b. Peccaries eat cacti with a smaller number of spines, and wasp larvae eat cacti with a greater number of spines. c. Wasps have increasing difficulty depositing eggs on cacti with more spines, and peccaries show no preference with respect to spine number. d. Both peccaries and wasp larvae will eat the most abundant types of cacti, which are the plants with the greatest number of spines.

b. Peccaries eat cacti with a smaller number of spines, and wasp larvae eat cacti with a greater number of spines.

In an experiment, 100 mice were released into a field to which no other mice had access. Immediately after their release, a representative sample of mice was captured, their fur color was recorded, and they were returned to the field. After twenty years, a representative sample of mice was captured and the distribution of fur color was again recorded. Which of the following could best explain the change in fur color distribution, as shown in the table above? a. The allele for black fur color is unstable, and over twenty years most of the black fur alleles mutated to become alleles for gray fur. b. The field was primarily composed of light-colored soil and little vegetation, affording gray mice protection from predators. c. Sexual selection led to increased mating frequency of black and brown versus gray and brown. d. The gray mice were harder to catch, and so were underrepresented in the twenty-year sample.

b. The field was primarily composed of light-colored soil and little vegetation, affording gray mice protection from predators.

Undersea landslides can disrupt marine habitats by burying organisms that live on the ocean floor. The graph above shows the size of a population of a certain organism that lives on the ocean floor. The population was affected by a recent landslide at the time indicated on the graph. Which of the following best predicts how the population will be affected by the landslide? a. The surviving organisms will evolve into a new species. b. The reduced population will likely have allelic frequencies that are different from the initial population. c. The population will adapt to deeper waters to avoid future landslides. d. The reduced population will have a greater number of different genes than the initial population.

b. The reduced population will likely have allelic frequencies that are different from the initial population.

A large population of laboratory animals has been allowed to breed randomly for a number of generations. After several generations, 25% of the animals display a recessive trait (aa), the same percentage as at the beginning of the breeding program. The rest of the animals show the dominant phenotype, with heterozygotes indistinguishable from the homozygous dominants. What is the most reasonable conclusion that can be drawn from the fact that the frequency of the recessive trait (aa) has not changed over time? a. The population is undergoing genetic drift. b. The two phenotypes are about equally adaptive under laboratory conditions, so little or no evolution is occurring. c. The genotype AA is lethal. d. There has been a high rate of mutation of allele A to allele a.

b. The two phenotypes are about equally adaptive under laboratory conditions, so little or no evolution is occurring.

A type of isolation in which two populations with complex courtship displays or rituals become different enough that they no longer respond to other's action a. geographical isolation b. behavioral isolation c. temporal isolation

b. behavioral isolation

The females of two species of fruit fly. Drosphila melanogaster and drosphila simulans release slightly different mating hormones called pheremones, which are used to attract male mates a. geographical isolation b. behavioral isolation c. temporal isolation

b. behavioral isolation

The fishing pattern of the firefly is used to attract the opposite sex. Female fireflies only flash back and attract male fireflies who first signal them with a species specific pattern of light. a. geographical isolation b. behavioral isolation c. temporal isolation

b. behavioral isolation

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 a. mutation b. genetic drift c. natural selection d. sexual selection e. heterozygote advantage

b. genetic drift

Cheetahs, the fastest of the land animals, have been hunted for their fur to near extinction. Examination of 52 different loci has failed to reveal any polymorphisms; that is, these animals are homozygous at all 52 loci. The lack of genetic variability is so profound that cheetahs will accept skin grafts from each other just as identical twins (and inbred mouse strains) do. This is an example of a. artificial selection. b. genetic drift. c. destabilizing selection. d. Hardy-Weinberg Principle.

b. 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 a. analogous structures b. homologous structures c. vestigial structures d. balanced polymorphism e. convergent 'evolution

b. homologous structures

Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease, what are the expected frequencies of the dominant (A1) and recessive (A2) alleles according to the Hardy-Weinberg model? a. (A1) = 0.9997, f(A2) = 0.0003 b. (A1) = 0.9800, f(A2) = 0.0200 c. (A1) = 0.9700, f(A2) = 0.0300 d. (A1) = 0.9604, f(A2) = 0.0392

c. (A1) = 0.9700, f(A2) = 0.0300

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) ? a. 0.09 b. 0.27 c. 0.30 d. 0.90 e. 0.97

c. 0.30

In a certain flock of sheep, 4 percent of the population has black wool and 96 percent has white wool. Assume that the population is in Hardy-Weinberg equilibrium. What percentage of the population is homozygous for white wool? a. 20% b. 40% c. 64% d. 80% e. 96%

c. 64%

Which of these naturalists synthesized a concept of natural selection independently of Darwin? a. Charles Lyell b. Gregor Mendel c. Alfred Wallace d. Thomas Malthus

c. Alfred Wallace

Which of the following is probably the best explanation for the fact that Antarctic penguins cannot fly, although there is evidence that millions of years ago their ancestors could do so? a. Penguins live on land and feed in the water; therefore they have no need to fly. b. The Antarctic home of penguins is flat and barren; therefore there is no place to fly. c. Ancestral penguins without large wings were better able to swim and feed in the water; therefore they passed their genes for shorter wing structure on to their offspring. d. Ancestral penguins did not use their wings for long periods of time; therefore today's penguins have only tiny, nonfunctional wings. e. The cold and wind of Antarctica make flight impossible; therefore penguins that live there have lost the ability to fly.

c. Ancestral penguins without large wings were better able to swim and feed in the water; therefore they passed their genes for shorter wing structure on to their offspring.

Lobe-finned fishes were present in the oceans of the world approximately 400 million years ago. The first tetrapods (vertebrates that had limbs and could move on land) date to about 365 million years ago. One hypothesis states that early tetrapods evolved from lobe-finned fishes. Which of the following is the best plan for testing the hypothesis? a. Determining the number of fins found on lobe-finned fishes from different geographical locations b. Measuring the proportion of radioisotopes found in fossils of early tetrapods c. Comparing the arrangements of bones in the fins of lobe-finned fishes and limbs of the earliest tetrapods d. Sequencing DNA isolated from fossils of lobe-finned fishes to determine the size of the genome

c. Comparing the arrangements of bones in the fins of lobe-finned fishes and limbs of the earliest tetrapods

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable. Condition 2: Some heritable traits must increase reproductive success. Condition 3: Individuals pass on most traits that they acquire during their lifetime. a. Condition 1 only b. Condition 2 only c. Conditions 1 and 2 d. Conditions 2 and 3

c. Conditions 1 and 2

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; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened? a. The herbicide company lost its triazine formula and started selling poor-quality triazine. b. Triazine-resistant pigweed has less-efficient photosynthesis metabolism. c. Triazine-resistant weeds were more likely to survive and reproduce. d. Triazine-resistant weeds mutated to become a new species.

c. Triazine-resistant weeds were more likely to survive and reproduce.

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) ? a. Large populations are not subject to natural selection. b. Random mating prevents gene flow from changing allele frequencies. c. Without migration or mutation, new alleles cannot be introduced to the population. d. In the absence of selection, allele frequencies in a population will not change.

c. Without migration or mutation, new alleles cannot be introduced to the population.

Over many years of a breeding program, a zoo has an established population of foxes that is well adapted for living in captivity. A representative sample of wild foxes from the neighboring forest was used to start the zoo population. A study was conducted to compare the behavior of the zoo fox population with the wild fox population in the neighboring forest. The behaviors of equal numbers of foxes from each population were assessed. Each fox's behavior was scored on a continuum from docile to aggressive based on its interaction with a trained behaviorist. The data is shown in Figure 1. Figure 1. Aggressive behavior in zoo and wild fox populations The phenotypic variation in behavior between the two populations can best be described as resulting from a. sexual selection b. natural selection c. artificial selection d. genetic drift

c. artificial selection

Sponges are known to contain a single Hox gene. Most invertebrates have a cluster of 10 similar Hox genes, all located on the same chromosome. Most vertebrates have four such clusters of Hox genes, located on four non-homologous chromosomes. The process responsible for the change in number of Hox genes from sponges to invertebrates was most likely __________, a. binary fission b. translation c. gene duplication d. non-disjunction

c. gene duplication

Even though they have become adapted for different functions, the forelimbs of all mammals are constructed from the same basic skeletal elements. This is an example of a. vestigial structures. b. analogous structures. c. homologous structures. d. molecular homologies.

c. homologous structures.

A type of isolation where two species whose ranges overlap have different periods of sexual activity or breeding seasons. a. geographical isolation b. behavioral isolation c. temporal isolation

c. temporal isolation

In the great lakes region of North America, gray wolves and coyotes are sterm-52imilar species but do not mate because their breeding periods occur at different times of the year a. geographical isolation b. behavioral isolation c. temporal isolation

c. temporal isolation

Of the 7 species of cicada, 3 follow a 17 year mating cycle, while 4 follow a 13 year mating cycle. In regions where their geographic range overlaps, their emergence coincides once in every 221 years. This last happened in North America in 2015 and will not occur again until the year 2236. a. geographical isolation b. behavioral isolation c. temporal isolation

c. temporal isolation

The American toad and Fowler's toad live in the same area. However, the American toad mates in early summer while Fowler's mates in late summer. a. geographical isolation b. behavioral isolation c. temporal isolation

c. temporal isolation

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? a. 0.36 b. 0.64 c. 0.75 d. 0.80

d. 0.80

If, on average, 31% of the loci in a species' gene pool are heterozygous, then the average homozygosity of the species should be a. 23%. b. 46%. c. 54%. d. 69%

d. 69%

In the wild, male house finches (Carpodus mexicanus) vary considerably in the amount of red pigmentation in their head and throat feathers, with colors ranging from pale yellow to bright red. These colors come from carotenoid pigments that are found in the birds' diets; no vertebrates are known to synthesize carotenoid pigments. Thus, the brighter red the male's feathers are, the more successful he has been at acquiring the red carotenoid pigment by his food-gathering efforts (all other factors being equal). During breeding season, one should expect female house finches to prefer to mate with males with the brightest red feathers. Which of the following is true of this situation? a. This is an example of sexual selection. b. Alleles that promote more effective deposition of carotenoid pigments in the feathers of males should increase over the course of generations. c. There should be directional selection for bright red feathers in males. d. All three of these.

d. All three of these.

Over several years, bacteria were isolated from members of a human population and tested for antibiotic resistance. The percent of bacterial isolates that were found to be antibiotic resistant is presented in the graph above for each year of the study. Which of the following conclusions is best supported by the information presented in the graph? a. The greatest increase in antibiotic resistance occurred from the first year to the third year of the study. b. Gene flow in the population occurred at the same rate for the entire duration of the eight-year study. c. Because evolution in bacterial populations occurs over millions of years, the results are due to random variation. d. Natural selection over multiple generations is favoring antibiotic resistance in the population of bacteria.

d. Natural selection over multiple generations is favoring antibiotic resistance in the population of bacteria.

In a hypothetical population of beetles, there is a wide variety of color, matching the range of coloration of the tree trunks on which the beetles hide from predators. The graphs below illustrate four possible changes to the beetle population as a result of a change in the environment due to pollution that darkened the tree trunks. Which of the following includes the most likely change in the coloration of the beetle population after pollution and a correct rationale for the change? a. The coloration range shifted toward more light-colored beetles, as in diagram I. The pollution helped the predators find the darkened tree trunks. b. The coloration in the population split into two extremes, as in diagram II. Both the lighter-colored and the darker-colored beetles were able to hide on the darker tree trunks. c. The coloration range became narrower, as in diagram III. The predators selected beetles at the color extremes. d. The coloration in the population shifted toward more darker-colored beetles, as in diagram IV. The lighter-colored beetles were found more easily by the predators than were the darker-colored beetles.

d. The coloration in the population shifted toward more darker-colored beetles, as in diagram IV. The lighter-colored beetles were found more easily by the predators than were the darker-colored beetles.

Students observed the distribution of different color phenotypes in northern ravine salamanders (Plethodon electromorphus) before and after a spring flood. The data are shown in Table 1. Table 1. Observed number of salamanders by phenotype before and after a spring flood Salamander Distribution before the Flood (nn)Salamander Distribution after the Flood (nn)Black phenotype137Dark-brown phenotype2514Light-brown phenotype63 Which of the following is an appropriate null hypothesis regarding the phenotypic frequencies of this population of salamanders before and after the flood? a. More black salamanders survived because they could better hide from predators on the dark muddy soil, so the frequency of the black phenotype significantly increased in the population after the flood. b. Fewer light-brown salamanders survived because they had a reduced chance of finding mates due to the high water levels, so the frequency of the light-brown phenotype in the population decreased after the flood. c. More dark-brown salamanders migrated to a new, drier area because of the flood and fewer of them remained in the original habitat, so the frequency of dark-brown salamander significantly decreased in the population after the flood. d. The proportions of black, dark-brown, and light-brown salamanders before and after the flood are not significantly different, and any observed differences are due to random chance.

d. The proportions of black, dark-brown, and light-brown salamanders before and after the flood are not significantly different, and any observed differences are due to random chance.

If a large population stopped reproducing sexually (but still reproduced asexually) how would its genetic variation be affected over time? a. The organism could switch to genetic mutations to achieve variability. b. Without sexual reproduction the population would rely on genetic drift to change gene frequency causing a reduction in variability. c. Without sexual reproduction the population would go extinct. d. Without sexual reproduction new sources of genetic variation would be reduced, lowering the genetic variation.

d. Without sexual reproduction new sources of genetic variation would be reduced, lowering the genetic variation.

Diagram 1, on this test, shows the distribution of pocket-mouse coat colors in several Arizona populations found either on light-colored granite substrate or on dark volcanic rock (dark substrate). The Melanocortin-1 receptor (Mc1r) alleles, D and d, differ by four amino acids. Mice with DD and Dd genotypes have dark coats, whereas mice with the dd genotype are light colored. What sort of genotype frequencies might you expect to find in the Xmas and Mid populations? a. Xmas-high DD frequency; Mid-high Dd frequency b. Xmas-high Dd frequency; Mid-high DD frequency c. Xmas-high dd frequency; Mid-high Dd frequency d. Xmas-high dd frequency; Mid-high DD frequency

d. Xmas-high dd frequency; Mid-high DD frequency

As a young biologist, Charles Darwin had expected the living plants of temperate South America would resemble those of temperate Europe, but he was surprised to find that they more closely resembled the plants of tropical South America. The biological explanation for this observation is most properly associated with the field of a. meteorology. b. vertebrate anatomy. c. bioengineering. d. biogeography.

d. biogeography.

In Darwin's thinking, the more closely related two different organisms are, the a. more similar their habitats are. b. less similar their DNA sequences are. c. less likely they are to have the same genes in common. d. more recently they shared a common ancestor.

d. more recently they shared a common ancestor.

In a hypothetical environment, fishes called pike-cichlids are visual predators of large, adult algae-eating fish (in other words, they locate their prey by sight). The population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following is LEAST likely to result in the algae-eater population in future generations? a. selection for drab coloration of the algae-eaters b. selection for nocturnal algae-eaters (active only at night) c. selection for algae-eaters that become sexually mature at smaller overall body sizes d. selection for larger female algae-eaters, bearing broods composed of more, and larger, young

d. selection for larger female algae-eaters, bearing broods composed of more, and larger, young

Sexual dimorphism is most often a result of a. pansexual selection. b. stabilizing selection. c. artificial selection. d. sexual selection.

d. sexual selection.

To observe natural selection's effects on a population, which of these must be true? a. One must observe more than one generation of the population b. The population must contain genetic variation. c. Members of the population must increase or decrease the use of some portion of their anatomy. d. A and C only e. A and B only

e. A and B only