Question

Determine whether the following scenarios are sex-linked, sex-limited or sex-influenced: "Roosters have a larger comb and wattles and longer neck and tail feathers than do hens. These features may be found in roosters, but never normal hens.

Answer 1

The characteristics of roosters mentioned are examples of sex-limited traits because they are only expressed in males due to hormonal differences, and this scenario is not directly related to sex-linked inheritance in birds, where females have ZW chromosomes and males have ZZ chromosomes.

Step-by-step explanation:

The scenario described where roosters have larger combs and wattles and longer neck and tail feathers than hens is an example of sex-limited traits. These traits are physically expressed only in one sex, the male, due to the hormonal differences between males and females, rather than being associated with the sex chromosomes directly. In birds, unlike mammals, sex determination involves Z and W chromosomes where males are ZZ (homozygous) and females are ZW (heterozygous). This is different from mammals, where females are XX and males are XY. Sex-linked traits in birds are more likely to appear in females since they are hemizygous, meaning they have only one copy of the Z chromosome which may carry such a trait.