In a certain taxon of insects some have 17 chromosomes and the others have 18 chromosomes. The 17 and 18 chromosome-bearing organisms are

Options

A. males and females, respectively.
B. females and males, respectively.
C. all males.
D. all females.

Answer

A

Explanation

In certain taxon of insects, 17 and 18 chromosome bearing organisms are males and females respectively. Because, insects have XO type of sex determination method. In certain insects, such as cockroach, and some roundworms lacks Y-chromosome, so that the male has only one sex chromosome, that is, X besides autosomes. This condition in the male is designated as XO (where O means absence of one sex chromosome) and in the female it is XX.