Nondisjunction of the X chromosomes may occur during formation of gametes and produce two kinds of eggs.If normal sperm fertilizes these two kinds of eggs,which of the following pairs of genotypes are possible?

Question

Quizplus · Accepted Answer

Nondisjunction of the X chromosomes during formation of gametes can produce two kinds of eggs, one with an extra X chromosome (XXY) and the other missing an X chromosome (XO). If normal sperm fertilizes these two kinds of eggs, the possible genotypes of offspring are XXY and XO. Therefore, option B (XXY and XO) is the correct answer. Option A (XX and XY) is incorrect because fertilization of normal sperm with two different types of eggs cannot produce a male with two X chromosomes. Options C (XYY and XO) and D (XYY and YO) are incorrect because they involve the fertilization of normal sperm with both types of eggs, which is not possible.

Nondisjunction of the X Chromosomes May Occur During Formation of Gametes