Question

Male heterogamy is not present in:

• A. Human
• B. Grasshopper - XO
• C. Drosophila - XY
• D. Honey bee - haploid-diploid

Hint:

Important sex-determination systems: \[ \boxed{ \begin{aligned} XY &\rightarrow \text{Human, Drosophila}\\ XO &\rightarrow \text{Grasshopper}\\ ZW &\rightarrow \text{Birds}\\ \text{Haplodiploid} &\rightarrow \text{Honey bee} \end{aligned} } \] Honey bees determine sex by chromosome number rather than sex chromosomes.

Answer 1

The Correct Option is D

Male heterogamy (XY system) means males produce two types of gametes (X-bearing and Y-bearing) and is found in humans and Drosophila. In birds, it is the female that is heterogametic (ZW system), so male heterogamy is absent in birds; Bombyx mori (silkworm) also follows the ZW pattern.