Question

In species of birds, males are the homogametic sex and females the heterogametic sex. Which if the following is TRUE in this system of sex determination?

a) Males have two different sex chromosomes (XY), and females have two identical sex chromosomes (XX).

b) Males have two identical sex chromosomes (XX), and females have two different sex chromosomes (XY).

c) Males determine the sex of offspring, and females have a fixed sex determined by their genotype.

d) Females determine the sex of offspring, and males have a fixed sex determined by their genotype.

Answer 1

In bird species, the correct system of sex determination is that males are ZZ (homozygous) and females are ZW (heterozygous), making females the ones to determine the sex of the offspring.

The correct statement is D.

Step-by-step explanation:

This means that the male birds are ZZ (homozygous) and the female birds are ZW (heterozygous). Therefore, it is the female that determines the sex of the offspring depending on whether she passes on a Z chromosome or a W chromosome. The male, contributing only Z chromosomes, has a fixed role in sex determination.

The correct option for the system of sex determination in bird species, where males are the homogametic sex and females the heterogametic sex, is d) Females determine the sex of offspring, and males have a fixed sex determined by their genotype.