Question

У человека ген, вызывающий гемофилию (несвёртываемость крови) рецессивен и локализован в X-хромосоме. Найди вероятность (%) рождения здоровых сыновей в семье, где мать — носитель гена гемофилии, отец здоров.

Answer 1

100% ........................

Answer 2

Understanding the Question

The question asks for the probability of having healthy sons in a family where the mother is a carrier of the hemophilia gene and the father is healthy. The hemophilia gene is recessive and located on the X chromosome.

Answer

To determine the probability of having healthy sons in this scenario, we need to consider the inheritance pattern of the hemophilia gene.

Hemophilia is an X-linked recessive disorder, which means that the gene responsible for hemophilia is located on the X chromosome. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Since the mother is a carrier of the hemophilia gene, she has one normal X chromosome and one X chromosome carrying the hemophilia gene. The father, on the other hand, is healthy and does not carry the hemophilia gene.

When the mother is a carrier, there are four possible combinations of X chromosomes that can be passed on to her children:

1. The mother can pass on her normal X chromosome, resulting in a healthy child. 2. The mother can pass on her X chromosome carrying the hemophilia gene, resulting in a son with hemophilia. 3. The mother can pass on her normal X chromosome, resulting in a healthy child. 4. The mother can pass on her X chromosome carrying the hemophilia gene, resulting in a daughter who is a carrier of the hemophilia gene.

Since we are specifically interested in the probability of having healthy sons, we can focus on the first and third possibilities. In these cases, the sons will receive the father's Y chromosome, which does not carry the hemophilia gene.

Therefore, the probability of having healthy sons in this family is 50%.