Q. Assertion : XX-XY type of sex determination mechanism is an example of female heterogamety and is found in Drosophila.
Reason : Male heterogamety is seen in moths where males produce two different types of gamete.

 2672  186 AIIMSAIIMS 2017Principles of Inheritance and Variation Report Error

Solution:

Chromosomal determination of sex is based on heterogamety or occurrence of two types of gamete in one of the two sexes. In Drosophila XX-XY type of sex determination is found where males are heterogametic. In moths, ZO-ZZ type of sex determination occur where males are homogametic.