ZZ/ZW type of sex determination is seen in

Options

A. platypus
B. snails
C. cockroach
D. peacock

Answer

D

Explanation

In ZZ/ZW case, the female has heteromorphic (ZW) sex chromosomes and the male has homomorphic (ZZ) sex chromosomes. Thus, peacock shows ZZ/ZW sex determination type.
In platpus the sex detemination is of XX-XY type. Both male and females has the sex chromosome each. The male XY, XY, XYmXY and female has XXXXXXXXXX.
In snails the sex determination is environmentally induced, while in cockroaches it is of XX-XO types.
In this type Y-chromosomes is completely lacking. In this type presence pf unpaired X-chromosomes determines the masculine sex.