Question

У человека наличие веснушек является доминантным признаком, а их отсутствие рецессивным: рыжие волосы-доминантный признак, а русые- рецессивный. Обе пары генов размещены в разных хромосомах. Какое потомство родителей можно ожидать в случае вступления в брак со следующими фенотипами и генотипами: а) отеп и мать имеют веснушки, но отец гомозиготен, а мать гетерозиготна по этому признаку; оба родителя с рыжими волосами и гетерозиготны по этому признаку. б) Отец с русыми волосами и не имеет веснушек, а мать с веснушками и рыжими волосами и гетерозиготна по обоим признакам

Answer 1

Ответ:

Объяснение:

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Answer 2

Inheritance of Freckles and Hair Color

The presence of freckles is considered a dominant trait, while their absence is considered a recessive trait. Similarly, red hair is a dominant trait, while brown hair is a recessive trait. These traits are determined by genes located on different chromosomes.

Let's analyze the two scenarios mentioned:

a) The father is homozygous for the absence of freckles, while the mother is heterozygous for freckles. Both parents have red hair and are heterozygous for this trait.

b) The father has brown hair and does not have freckles, while the mother has freckles and red hair. The mother is heterozygous for both traits.

Scenario a: Father is homozygous for the absence of freckles, mother is heterozygous for freckles, both parents have red hair and are heterozygous for this trait.

In this scenario, the father's genotype for freckles is ff (homozygous recessive), and the mother's genotype for freckles is Ff (heterozygous dominant/recessive). The father's genotype for hair color is RR (homozygous dominant), and the mother's genotype for hair color is Rr (heterozygous dominant/recessive).

The possible genotypes and phenotypes of their offspring can be determined using a Punnett square:

| | f | f | |-------|----------|----------| | R | Rf | Rf | | R | Rf | Rf |

From the Punnett square, we can see that all the offspring will have the genotype Rf (heterozygous for both freckles and hair color) and will have red hair and freckles as their phenotype.

Scenario b: Father has brown hair and no freckles, mother has freckles and red hair, and is heterozygous for both traits.

In this scenario, the father's genotype for freckles is ff (homozygous recessive), and the mother's genotype for freckles is Ff (heterozygous dominant/recessive). The father's genotype for hair color is rr (homozygous recessive), and the mother's genotype for hair color is Rr (heterozygous dominant/recessive).

The possible genotypes and phenotypes of their offspring can be determined using a Punnett square:

| | f | f | |-------|----------|----------| | r | rf | rf | | R | Rf | Rf |

From the Punnett square, we can see that all the offspring will have the genotype Rf (heterozygous for both freckles and hair color) and will have red hair and freckles as their phenotype.

In both scenarios, the offspring will have red hair and freckles, regardless of the father's genotype for freckles or hair color.