Question

Sol.(d) [Key Concept: ZZ/ZW Sex Determination — Birds] ZZ/ZW type of sex determination is seen in PEACOCK (birds in general). In birds: females are ZW (heterogametic sex, like XY males in mammals) and males are ZZ (homogametic sex, like XX females in mammals). The sex roles are REVERSED compared to mammals — females are the heterogametic sex in birds. This ZZ/ZW system is also seen in some butterflies, moths, and fish. Platypus has XX/XY system; cockroaches have XX/XO system; snails have environmental sex determination.