BIOL 1001 WEEK 5 EXAM WITH ANSWERS Fall 2022

Which individuals have the greatest fitness in an area where malaria is common? Correct Answer: e. Individuals heterozygous for the normal and sickle cell anemia alleles • Question 9 2 out of 2 points Your friend was diagnosed with strep throat 2 months ago. She was treated with antibiotics for 10 days, but 2 weeks after treatment, the symptoms returned. She was given a different antibiotic, and her symptoms again initially improved but then got worse. What is happening? Choose the best answer. Correct Answer: c. Your friend was originally infected with bacteria that are resistant to at least two antibiotics. • Question 10 2 out of 2 points A biologist has been studying two populations of trout in Montana for the last 25 years, when the two populations were established from one common population. In the southern population, the fish now have a slightly different mouth shape. But the northern population hasn’t changed from the original type. The new shape works well in catching the type of prey common in the habitat of the southern population. Which explanation is the most likely explanation of the gene differences in the two populations? Correct Answer: d. The gene that produces the variation is probably still present in a small percentage of the northern population, but since there’s no advantage to having it, individuals with the variation aren’t preferentially selected. • Question 11 2 out of 2 points Which of the following occurs after the creation of a new allele? Correct Answer: b. The gene pool becomes more diverse. • Question 12 2 out of 2 points In a population where most of the individuals have long, narrow noses, a child is born with a shorter, broader nose. What’s the most likely explanation for this variation? Correct Answer: a. The child reflects the normal variation around the average type. • Question 13 2 out of 2 points What is the evolutionary origin of light skin in humans? Correct Answer: a. Light skin evolved several times in response to low ultraviolet light levels. • Question 14 3 out of 3 points Which of the following is true of individuals who are well adapted for a particular environment? Correct Answer: c. They may or may not be equally fit in another environment. • Question 15 2 out of 2 points You notice that some squirrels in your neighborhood have a much darker coat color than most of the other squirrels. Is this darker color an adaptation? Correct Answer: b. The trait is only an adaptation if it gives the squirrels an advantage in their habitat. • Question 16 2 out of 2 points Which of the following traits can be acted on by natural selection? Correct Answer: e. All of these can be acted on by natural selection, as long as they’re controlled by genes.