The amino acid sequence of cytochrome c is exactly the same…
The amino acid sequence of cytochrome c is exactly the same in humans and chimpanzees. There is a difference of 13 amino acids between the cytochrome c of humans and dogs, and a difference of 20 amino acids between the cytochrome c of humans and rattlesnakes. Which of the following statements is best supported by these data?
Read DetailsWhich of the following correctly compares the two processes…
Which of the following correctly compares the two processes shown above? The first process is fertilization. A sperm fusing with an egg is shown. The second process is transduction. A five step process is shown. Step 1. Virus attaches to cell surface and inserts viral DNA into cell. Step 2. The cell’s circular DNA is broken into many pieces. Step 3. new viral particles are formed in the cell that include DNA from the host cell. Step 4. One of the new viral particles infects another cell. Step 5. The DNA from the virus is inserted into the circular chromosome of the shot cell.
Read DetailsA current challenge for doctors involves the bacterial strai…
A current challenge for doctors involves the bacterial strain Clostridioides difficile, which no longer responds to traditional antibiotic treatments. Which of the following best explains why this particular strain of bacteria is resistant to antibiotic treatment?
Read DetailsStickleback fish are found in both marine and freshwater hab…
Stickleback fish are found in both marine and freshwater habitats. The marine fish have no scales but have hardened, armorlike plates along their sides. The plates are thought to protect sticklebacks from certain predators. In the late 1980s, sticklebacks from a marine population colonized Loberg Lake, a freshwater lake in Alaska. Starting in 1990, researchers sampled fish from the lake every four years and recorded the armor-plate phenotypes of the male sticklebacks in each sample. The armor-plate phenotypes were categorized as either complete (plates extending from head to tail), partial (plates extending from head to abdomen), or low (a few plates near the head only). The results are shown in the table below. ARMOR-PLATE VARIATION IN THE STICKLEBACK POPULATION OF LOBERG LAKE Percent of Males in the Sample with Each Armor-Plate Phenotype Year Low Partial Complete 1990 1% 2% 97% 1994 45% 14% 41% 1998 58% 16% 26% 2002 76% 15% 9% 2006 90% 6% 4% Which of the following best explains the changes in the phenotype frequencies of the stickleback population in Loberg Lake?
Read DetailsAfrican elephants, Loxodonta africana, are often hunted ille…
African elephants, Loxodonta africana, are often hunted illegally for their tusks. Both male and female elephants have tusks, although the tusks are much larger in the males. Researchers have followed the elephant population in Gorongosa National Park in Mozambique for many years. Figure 1 shows the percent of tuskless female elephants expected in wild populations throughout the species’ range, as well as the percent of tuskless females that survived the hunting between 1977 and 1992 (those over 25 years old) and the percent of female elephants born after 1992 without tusks in the park. The data are based on 200 known female elephants in the park. There are 3 categories indicated along the horizontal axis: Wild Population, Females Older Than 25, and Females Born After 1992. The vertical axis is labeled Percent of Tuskless Females, and the numbers 0 through 100, in increments of 20, are indicated. The following data is represented by the graph. Wild Population, 4 percent of Tuskless Females. Females Older Than 25, 51 percent. Females Born After 1992, 32 percent. Figure 1. Comparison of the frequency of tuskless females by age cohort Which of the following best describes the process responsible for the change in the percent of tuskless female elephants in the Gorongosa National Park population shown in Figure 1?
Read DetailsIn a hypothetical population of beetles, there is a wide var…
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. All graphs have a y axis labeled population frequency, and an x axis labeled beetle color from light on the left to dark on the right. On graph one, the original population is a wide bell curve that begins a short distance to the right of light on the x axis and ends the bell curve at dark on the right side. The population after pollution is a bell curve that begins all the way at light on the left side and ends approximately halfway between light and dark. On graph two the original population is a wide bell curve that begins on the left side at light and ends on the right side at dark, with the peak in the center. The population after pollution is a curve with two peaks, the first peak is on the light side and the second peak is on the dark side, dropping in the middle in between both peaks.On graph three the original population is a wide bell curve that begins on the left side at light and ends on the right side at dark, with the peak in the center. The population after pollution is a narrow bell curve that fits under the original population bell curve, beginning to the right of left and ending to the left of dark.On graph four two the original population is a wide bell curve that begins on the left side at light and ends on the right side at dark, with the peak in the center. The population after pollution is bell cure that is narrower than the original population’s bell curve, beginning just before the middle of the graph and ending to the right of the original population on the dark side. 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?
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