ZZ/ZW type of sex determination is seen in

Options

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

Answer

D

Explanation

ZZ/ZW, type of sex determination is seen in birds, reptiles and fish. Thus, peacock shows ZZ/ZW sex determination type. In this type, female has heteromorphic (ZW) sex chromosomes and the male has homomorphic (ZZ) sex chromosomes. In Platypus the sex determination is of XX-XY type in which both male and females has ten sex chromosome each. The male has XY, XY, XY, XY, XY and female has XX, XX, XX, XX, XX. In snails, the sex determination is environmentally induced, while in cockroaches it is of XX-XO types. In this type Y-chromosome is absent. In this the presence puffs unpaired X-chromosomes determines the masculine sex.