Chromosomes 'Z' and 'W' for sex determination are seen in:

The correct answer is Option (3) → Birds

In birds, the female makes two kinds of gametes with respect to the sex chromosomes; this is female heterogamety. Females are ZW and males are ZZ, so the egg decides the sex of the chick.

Option (1) Human — Incorrect. Humans have the XX-XY type. Females are XX and males XY, so the father’s sperm decides the sex.

Option (2) Grasshopper — Incorrect. Grasshoppers have the XX-XO type. Males have only one X and no second sex chromosome.

Option (3) Birds — Correct. In birds the female has two different sex chromosomes, Z and W, and the male has two Z (ZZ). So in birds the sex of the chick depends on the egg, not the sperm.

Option (4) Drosophila — Incorrect. Drosophila has the XX-XY type, like humans.

NCERT Extract:
Sex Determination – “… In some other organisms, e.g., birds, a different mechanism of sex determination is observed (Figure 4.12 c). In this case the total number of chromosome is same in both males and females. But two different types of gametes in terms of the sex chromosomes, are produced by females, i.e., female heterogamety. In order to have a distinction with the mechanism of sex determination described earlier, the two different sex chromosomes of a female bird has been designated to be the Z and W chromosomes. In these organisms the females have one Z and one W chromosome, whereas males have a pair of Z-chromosomes besides the autosomes.”