Critical Thinking Activities - Chapter 13

Question 1. The Y-chromosome is shorter than the X-chromosome, accounting for about four percent less mass to the sperm cell. However, when millions are deposited and must travel a relatively long distance with equal propulsion, this difference in mass should result in what difference in male and female zygotes produced?

Question 2. Malaria has not been a serious health problem in the southern United States this century, but it remains a serious disease in Africa today. If we examined just the African American population descended from Africans brought to the United States from the malaria regions of Africa, how would the proportion of sickle-cell genes in these gene pools compare? What would occur to these gene frequencies over time if there was a resurgence of malaria in the United States?

Answers are available to instructors in the Instructor's Manual.
Back to Critical Thinking Activities