Individuals of a particular species of ground beetle are either light tan or dark brown. Light-tan beetles are predominant in habitats with light-colored sandy soils, and dark-brown beetles are predominant in habitats with dark-colored loam soils. In an experiment designed to determine the survival rates of light-tan beetles and dark-brown beetles in different habitats, 500 light-tan beetles and 500 dark-brown beetles were released in each of four habitats. Each beetle had been marked with a small spot of red paint on the underside of its abdomen before it was released. One week after the beetles had been released, any marked beetles that could be found were recaptured. The results are presented in the table below. It is assumed that differences in the numbers of beetles recaptured are directly related to differences in survival rates. Columns 2 thru 5 have 2 sub-columns each. The top row contains the column labels: columns one is blank; Column two: Habitat 1: Sandy soil, no insectivorous birds present. Column three: Habitat 2: Sandy soil, insectivorous birds present. Column four: Habitat 3: Loam soil, no insectivorous birds present. Column five: Loam soil, insectivorous birds present. From top to bottom the data is as follows: Row two: Color of Beetle: Habitat 1, sub-column one, Light tan; sub-column two, Dark brown. Habitat 2, sub-column one, Light tan; sub-column two, Dark brown. Habitat 3, sub-column one, Light tan; sub-column two, Dark brown. Habitat 4, sub-column one, Light tan; sub-column two, Dark brown. Row three: Number Released: Habitat 1, sub-column one, five hundred; sub-column two, five hundred. Habitat 2, sub-column one, five hundred; sub-column two, five hundred. Habitat 3, sub-column one, five hundred; sub-column two, five hundred. Habitat 4, sub-column one, five hundred; sub-column two, five hundred. Row four: Number Recaptured: Habitat 1, sub-column one, one hundred thirty; sub-column two, one hundred fourteen. Habitat 2, sub-column one, one hundred twenty-three; sub-column two, twenty-two. Habitat 3, sub-column one, sixty-five; sub-column two, seventy-four. Habitat 4, sub-column one, thirteen; sub-column two, eighty-seven. Which of the following can be inferred from the data in the table?

Sickle-cell anemia results from a point mutation in the HBB gene. The mutation results in the replacement of an amino acid that has a hydrophilic R-group with an amino acid that has a hydrophobic R-group on the exterior of the hemoglobin protein. Such a mutation would most likely result in altered

Tay-Sachs disease is a rare inherited disorder caused by an autosomal recessive allele of the HEXA gene. Affected individuals exhibit severe neurological symptoms and do not survive to reproductive age. Individuals who inherit one copy of the allele (Tay-Sachs carriers) typically show no symptoms of the disorder. The frequencies of Tay-Sachs carriers in the general population of North America and in three different subpopulations are presented in the table. For general population the frequency is 0.004. For subpopulation 1 the frequency is 0.037. For subpopulation 2 the frequency is 0.035. For subpopulation 3 the frequency is 0.020. Based on the information presented, which of the following best explains the difference in phenotype between Tay-Sachs carriers and homozygous recessive individuals?

Iron is an essential nutrient that is acquired by organisms from the environment. When intracellular levels of iron are relatively high, living cells synthesize an iron-storage protein called ferritin. The induction of ferritin synthesis by iron was investigated in rats. Figure 1 shows the results of an experiment in which cellular levels of ferritin protein were measured in the presence or absence of iron and actinomycin D, a drug that inhibits transcription. Figure 2 shows the results of an experiment in which cellular levels of ferritin protein were measured in the presence or absence of iron and cycloheximide, a drug that inhibits translation. The horizontal axes are labeled Treatment, and the vertical axes are labeled Relative Protein Level. Five tick marks appear on the vertical axis, from bottom to top, the first tick mark is labeled zero, the third tick mark is labeled one point zero, and the fifth tick mark is labeled two point zero. The graph on the left is labeled Figure one. Ferritin Protein Levels. Four vertical bars appear along the horizontal axis, and the presence or absence of Iron and Actinomycin D is indicated above each bar. The data in the graph, from left to right, are as follows: Bar 1: Absence of Iron; Absence of Actinomycin D; Relative Protein Level one point zero. Bar 2: Presence of Iron; Absence of Actinomycin D; Relative Protein Level two point two. Bar 3: Absence of Iron; Presence of Actinomycin D; Relative Protein Level zero point nine. Bar 4: Presence of Iron; Presence of Actinomycin D; Relative Protein Level two point zero. The graph on the right is labeled Figure 2. Ferritin Protein Levels. Four vertical bars appear along the horizontal axis, and the presence or absence of Iron and Cycloheximide is indicated above each bar. The data in the graph, from left to right, are as follows: Bar 1: Absence of Iron; Absence of Cycloheximide; Relative Protein Level one point zero. Bar 2: Presence of Iron; Absence of Cycloheximide; Relative Protein Level two point five. Bar 3: Absence of Iron; Presence of Cycloheximide; Relative Protein Level zero point nine. Bar 4: Presence of Iron; Presence of Cycloheximide; Relative Protein Level zero point nine. Which of the following biotechnology approaches could be used to identify ferritin mRNA in a sample of total cellular RNA?

Diapause is the interruption of an organism’s life cycle in response to the environmental cues. The soil nematode Caenorhabditis elegans is capable of entering entering adult reproductive diapause (ARD) when food is scarce. In C. elegans, individuals normally become reproductively mature 2 days after hatching and remain fertile for 18 days. They reproduce either by self-fertilization or by mating with another individual. In an investigation, researchers examined the survival and reproductive success of female C. elegans who were without food for 0-30 days. Groups of C. elegans were held in ARD for different numbers of days before reintroduction of food. Average brood sizes (average number of offspring per adult) were determined following either self fertilization or mating with a well-fed males. The results are shown in Figure 1. There are tick marks on the horizontal axis labeled from left to right: 0, 3 through 15 in increments of 2, and 30, with a break indicated between 15 and 30. The vertical axis has evenly spaced tick marks labeled from 0 to 450 in increments of 50. There are two bars on each of the tick marks on the horizontal axis. In each pair, the unshaded bar represents self-fertilized and the shaded bar represents mated. Each bar also shows an error bar. From left toright, the data are as follows. All numbers are approximate. 0 days: self-fertilized, 260, error bar from 255 to 265; mated, 375, error bar from 325 to 420. 3 days: self-fertilized, 190, error bar from 185 to 200; mated, 245, error bar from 240 to 250. 5 days: self-fertilized, 120, error bar from 115 to 125; mated, 150, error bar from 140 to 170. 7 days: self-fertilized, 75, error bar from 70 to 80; mated, 125, error bar from 120 to 130. 9 days: self-fertilized, 50, error bar from 49 to 51; mated, 110, error bar from 95 to 115. 11 days: self-fertilized,40, error bar from 38 to 41; mated, 120, error bar from 110 to 130. 13 days: self-fertilized, 25, error bar from 24 to 26; mated, 100, error bar from 90 to 110.15 days: self-fertilized, 10, error bar from 9 to 11; mated, 125, error bar from 120 to 130. 30 days: self-fertilized, 5, error bar from 3 to 7; mated, 45, error bar from 35 to 50. The caption on the figure reads: Figure 1. Mean brood sizes plus or minus two times the standard error of the mean after different times in A R D. Individual C. elegans were held in A R D and subsequently allowed to reproduce either via self-fertilization (unshaded bars) or by mating with well-fed males (shaded bars). Figure 1. Mean brood sizes ± SEg after different times in ARD. Individual C. elegans were held in ARD and subsequently allowed to reproduce either via self-fertilization (unshaded bars) or by mating with well-fed males (shaded bars). In a second experiment, individuals were held in ARD without food for 0-30 days and monitored for average survival times following reintroduction of food (Figure 2). There are tick marks on the horizontal axis labeled from left to right: 0, 3 through 15 in increments of 2, and 30, with a break indicated between 15 and 30. The vertical axis has evenly spaced tick marks labeled 0 to 30 in increments of 5. Each bar shows an error bar. From left to right, the data are as follows. All numbers are approximate. 0 days: 18, error bar from 15 to 21. 3 days: 15, error bar from 12 to 18. 5 days: 18, error bar from 15 to 22. 7 days: 19, error bar from 17 to 23. 9 days: 19, error bar from 16 to 23. 11 days: 17, error bar from 14 to 20. 13 days: 16, error bar from 12 to 20. 15 days: 19, error bar from 16 to 23. 30 days: 22, error bar from 18 to 24. The caption on the figure reads: Figure 2. Mean survival plus or minus two times the standard error of the mean following different times in A R D. Individual C. elegans were held in A R D and subsequently given access to food, whereupon their survival times were determined. Figure 2. Mean survival ± SEg following different times in ARD. Individual C. elegans were held in ARD and subsequently given access to food, whereupon their survival times were determined. Which of the following best describes the reproductive ability of C. elegans following the ARD induced in the first experiment?

Female European corn borer moths (Ostrinia nubilalis) produce the sex pheromone 11−tetradecenyl acetate (11−TDA), which attracts males of their species. 11−TDA can be produced in two forms, E and Z, each with a different three-dimensional shape. Researchers have discovered two different strains of the European corn borer moth living in the same area. Females of the E strain produce primarily the E form of 11−TDA and females of the Z strain produce primarily the Z form of 11−TDA. Males of both strains are more attracted to the form of 11−TDA produced by the females of the same strain. Which of the following best predicts a long-term effect of the differences between the E and Z strains?

In a long‑term study of a population of gray squirrels, researchers observed that most of the squirrels had gray fur. However, there were some individuals in the population with white fur (albino). Genetic analysis revealed that the albino condition is expressed by individuals who are homozygous recessive (gg). Over a ten-year period, the average frequency of albino squirrels in the population was 0.18. If the population is assumed to be in Hardy-Weinberg equilibrium, the average frequency of the dominant allele is closest to which of the following?

Which of the following is most likely to create genetic variation in a population?

A small number of lizards from a mainland population have been deposited on four isolated islands because of the effects of a rare strong storm. Which of the following best predicts the outcome of these lizards reproducing for many generations on the islands?

Some scientists claim that amphibians are currently experiencing a period of mass extinction. Which of the following should be included in an alternative hypothesis that would best support this claim?