(i) Why are grasshopper and Drosophila said to show male heterogamity ? Explain.
(ii) Explain female heterogamity with the help of an example.

Explanation

(i) Drosophila and Grasshopper show heterogamity of XX-XY type in which the male is heterogametic with genotype A +XY and female is homogametic with genotype A+ XX
(ii) The female heterogamety is exhibited by birds In birds the female is heterogametic with genotype A+ZW and the male is homogametic with genetic constitution of A+ZZ Therefore in birds. the eggs determines the sex of the offspring raiher than malers as in humans