Question

XX-XO type of sex determination and XX-XY type of sex determination are examples of

• A. male heterogamety
• B. female heterogamety
• C. male homogamety
• D. female homogamety

Answer 1

The correct option is A

Explanation of the correct option:

1. XX-XO type, for example in grasshoppers, males have AA+XO and females have AA+XX chromosomes. AA represents autosomes which are common in all somatic cells.
2. XX and XO and XX are allosomes that determine sex.
3. Gametes from female AA+XX will be of one type: (A+X), homogametic.
4. Gametes from male AA+XO will be of two types: (A+X) and (A+O), heterogametic.
5. XX-XY type, for example in humans, males have AA+XY(44+XY) and females have AA+XX (44+XX) chromosomes in their diploid cells.
6. Gametes from males (44+XY) will be of two types: (22+X) and (22+Y), heterogametic.
7. Gametes from females (44+XX) will be of one type: (22+X), homogametic.
   This type of sex determination is an example of male heterogamety.

Final answer: XX-XO type of sex determination and XX-XY type of sex determination are examples of male heterogamety