Sex determination in grasshopper is of -

The correct answer is Option (2) → XX-XO type

Option (1) XX-XY type — Incorrect. Here the female is XX and the male is XY, as in humans and Drosophila. The male grasshopper has no Y chromosome.

Option (2) XX-XO type — Correct. The female grasshopper has two X chromosomes, but the male has only one X and no partner for it (O). So the male makes two kinds of sperms, with and without an X, and the sperm decides the sex.

Option (3) ZZ-ZO type — Incorrect. This is not one of the types the book describes. Where Z and W are used, as in birds, it is the female that has the two different sex chromosomes.

Option (4) ZZ-ZW type — Incorrect. This is the type found in birds: the female is ZW and makes two kinds of eggs, while the male is ZZ.

Note: A similar question was also asked in CUET (UG) 2026 on 24-05-2026 (Slot 2).

NCERT Extract:
Sex Determination – “… Due to the involvement of the X-chromosome in the determination of sex, it was designated to (b) be the sex chromosome, and the rest of the chromosomes were named as autosomes.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.”