Question

У человека ген, вызывающих одну из форм наследственной глухонемоты рецессивен по отношению гена нормального слуха. а) Какое потомство можно ожидать от брака гетерозиготных родителей? б)от брака глухонемой женщины с нормальным мужчиной родился глухонемой ребёнок. Определите генотипы родителей.

Answer 1

Inheritance of Deafness and Muteness

If a person has a gene that causes one form of inherited deafness and muteness, and this gene is recessive compared to the gene for normal hearing, we can determine the expected offspring from different scenarios.

a) Offspring from Heterozygous Parents: When both parents are heterozygous for the gene, meaning they have one normal gene and one gene for deafness and muteness, the possible genotypes and phenotypes of their offspring can be determined using a Punnett square.

Let's represent the normal gene for hearing as 'H' and the gene for deafness and muteness as 'h'. The genotypes of the parents are Hh.

The Punnett square for this scenario would look like this:

| | H | h | |------|-------|-------| | H | HH | Hh | | h | Hh | hh |

From this Punnett square, we can see that there is a 25% chance of having a child with the genotype 'HH' (normal hearing), a 50% chance of having a child with the genotype 'Hh' (carrier of the gene but with normal hearing), and a 25% chance of having a child with the genotype 'hh' (deaf and mute).

b) Offspring from a Deaf and Mute Woman and a Normal Man: If a deaf and mute woman (hh) marries a normal man (HH), the possible genotypes and phenotypes of their offspring can also be determined using a Punnett square.

The Punnett square for this scenario would look like this:

| | H | H | |------|-------|-------| | h | Hh | Hh |

From this Punnett square, we can see that all the children will have the genotype 'Hh' (carrier of the gene but with normal hearing).

Please note that these predictions are based on the assumption that the inheritance of deafness and muteness follows simple Mendelian genetics, which may not always be the case in reality. Other factors and genes may also contribute to the development of deafness and muteness.

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