Biology : PU-CET (U.G) 2017 Panjab University Entrance Exam With Answers

Practice Mode:
6.

XX-XO Sex Chromosome Complement Occurs In :

A: Cockroach
B: Honey Bee
C: Human Being
D: Chimpanzee

The answer is: A

Explanation

The XX-XO sex chromosome complement occurs in certain species of insects, including the cockroach. Therefore, the answer is A) Cockroach.

In this type of sex determination system, females have two X chromosomes (XX), while males have only one X chromosome (XO), as they do not receive a second sex chromosome from the father. Other examples of species with XX-XO sex determination include some species of grasshoppers and crickets.

Honey bees have a different sex determination system, known as haplodiploidy, where females are diploid (having two sets of chromosomes) and develop from fertilized eggs, while males are haploid (having one set of chromosomes) and develop from unfertilized eggs. Humans and chimpanzees have a different sex chromosome complement, known as XX-XY, where females have two X chromosomes and males have one X and one Y chromosome.