Question

У людини далекозорість - домінантна ознака (А) , нормальний зір - рецесивна ознака (а) . Який генотип можуть мати : а) люди з нормальним зором; б) далекозорі люди

Answer 1

Так как нормальное зрение - это рецессивный признак, то проявится он может только тогда когда человек будет гомозиготен по этому признаку, следовательно он будет иметь генотип аа
Дальнозоркость, являясь признаком вызываемым доминантным геном может проявится как в гомозиготном (АА), так и в гетерозиготном (Аа) состоянии гена.

Answer 2

Understanding the Genotype for Farsightedness and Normal Vision

Farsightedness, also known as hyperopia, is a condition where a person has difficulty seeing objects up close. On the other hand, normal vision refers to the ability to see objects clearly at various distances. In this case, farsightedness is considered the dominant trait (A), while normal vision is the recessive trait (a).

To determine the possible genotypes for individuals with normal vision and farsightedness, we can use the Punnett square method. The Punnett square is a tool used to predict the possible combinations of alleles (gene variants) that can be inherited from parents.

Genotypes of Individuals with Normal Vision and Farsightedness

1. Individuals with Normal Vision (aa): If both parents have normal vision, they would have the genotype aa. Since normal vision is a recessive trait, both alleles must be lowercase (a) for an individual to have normal vision. Therefore, individuals with normal vision can only have the genotype aa.

2. Individuals with Farsightedness (AA or Aa): If one or both parents have farsightedness, they can have either the genotype AA or Aa. Since farsightedness is a dominant trait, individuals with either one or two copies of the dominant allele (A) will exhibit farsightedness.

- If both parents have farsightedness (AA x AA), their offspring will inherit two copies of the dominant allele (A), resulting in the genotype AA. - If one parent has farsightedness and the other has normal vision (Aa x aa), their offspring have a 50% chance of inheriting the dominant allele (A) from the farsighted parent and a 50% chance of inheriting the recessive allele (a) from the parent with normal vision. This would result in a genotype of Aa, which would still exhibit farsightedness.

In summary, individuals with normal vision will have the genotype aa, while individuals with farsightedness can have either the genotype AA or Aa.