Question

If the diploid number of chromosomes in female grasshopper is 2n, then the number of chromosomes in sperms in this insect would be
[0.7 mark]

• A. 50% (n), 50% (n – 1)
• B. 50% (n), 50% (n + 1)
• C. 100% (n)
• D. 100% (n – 1)

Answer 1

The correct option is A 50% (n), 50% (n – 1)

Grasshopper is an example of XO type of sex determination in which the males have only one X-chromosome besides the autosomes, whereas females have a pair of X chromosomes. Chromosome of male grasshopper is AA + XO. Since, males have only one sex chromosome, 50% sperms will have one sex chromosome and 50% will lack the sex chromosome. In this way, the number of chromosomes in sperms will be 50% (n) and in 50% (n – 1).