Question

У кур породы плимутрок доминантный ген серой окраски оперения (Р) локализован в Z-хромосоме. Его рецессивный аллель (р) вызывает черную окраску оперения. Гомозиготный серый петух скрещен с курицей, у которой черная окраска оперения. Определите фенотипы птенцов в первом поколении. Составьте схему наследования.

Answer 1

Думаю примерно вот так:

Answer 2

Inheritance of Plumage Color in Plymouth Rock Chickens

The Plymouth Rock chicken breed exhibits a dominant gene for gray plumage color, which is localized on the Z-chromosome. The recessive allele for black plumage color is denoted by 'p'. When a homozygous gray rooster is crossed with a black-plumaged hen, we can determine the phenotypes of the offspring in the first generation.

According to the information provided, the gray plumage color is dominant (R) and the black plumage color is recessive (p). Therefore, the genotypes of the parent birds can be represented as follows:

- Homozygous gray rooster: RR - Black-plumaged hen: pp

To determine the phenotypes of the offspring, we can use a Punnett square. In this case, since the rooster is homozygous for the gray plumage color, all of its gametes will carry the dominant allele (R). The hen, being black-plumaged, can only produce gametes with the recessive allele (p).

The Punnett square for this cross would look like this:

| | R | R | | ---- | ----- | ----- | | p | Rp | Rp | | p | Rp | Rp |

From the Punnett square, we can see that all of the offspring in the first generation will have the genotype Rp, which means they will be heterozygous for the gray plumage color. However, since the gray plumage color is dominant, the phenotypes of all the chicks will be gray.

Therefore, the phenotypes of the chicks in the first generation will be gray.

Please note that this answer is based on the information provided and assumes that there are no other genetic factors influencing plumage color in Plymouth Rock chickens.