Question

Атрофия зрительного нерва наследуется как рецессивный признак, сцепленный с х хромосомой. нормальная женщина выходит замуж за мужчину, страдающего этой болезнью. у них рождается больная дочь и здоровый сын. определите вероятность рождения следующего ребенка без аномалии

Answer 1

Дано: Х(А) - норма
Х(а) - атрофия.

Найти: вероятность рождения ребёнка без аномалии.

Решение:
P: (мама) X(A)X(a) x X(a)Y
G: X(A) X(a) Y
F¹: X(A)X(a) (норма) X(A)Y (норма) X(a)X(a) (атрофия) X(a)Y (атрофия)

Ответ: 0,5 или 50%

Answer 2

Understanding the Inheritance Pattern of Optic Nerve Atrophy

Optic nerve atrophy is inherited as a recessive trait, linked to the X chromosome. When a normal woman marries a man suffering from this condition, they have a diseased daughter and a healthy son. Let's calculate the probability of the next child being born without the anomaly.

Probability Calculation

The probability of the next child being born without the anomaly can be calculated using the principles of genetics and Punnett squares. In this case, since the woman is normal and the man is affected by the disease, the man's genotype would be X^hY, where X^h represents the X chromosome carrying the gene for optic nerve atrophy, and Y represents the Y chromosome. The woman's genotype would be XX.

The Punnett square for this cross would be as follows:

| | X^h | Y | |---|-----|---| | X | X^hX | XY |

From this Punnett square, we can see that all daughters will be carriers (X^hX) and all sons will be healthy (XY).

Therefore, the probability of the next child (regardless of gender) being born without the anomaly is 50%.

This probability is based on the principles of genetic inheritance and the specific scenario described.

If you have any further questions or need additional information, feel free to ask!