Question

Помогите решать задачуу человека нос горбинкой (А) доминантный признак, а прямой нос- рецессивный. Полные губы (В) доминантный признак,а тонкие губы-рецессивный. Гены обоих признаков находятся в разных хромосомах. Мужчина имеющий нос с горбинкой и тонкие губы, мать которого имела прямой нос и полные губы, женился на женщине с прямым носом и тонкими губами. Определите генотипы родителей и возможные генотипы и фенотипы потомков. С какой вероятностью в этой семье могут родиться дети с полными губами? в соответствии с каким законом происходит наследование данных признаков?

Answer 1

Генотипы Родителей: мужчина Аавв, женщина аавв.
Генотипы потомства: Аавв, аавв
Фенотипы потомства: нос горбинкой и узкие губы, прямой нос и узкие губы
Вероятность рождения детей с полными губами = 0%
Мне кажется, что это 3-ий закон Менделя

Answer 2

Problem Analysis

In this problem, we are given information about two dominant and recessive traits: a humped nose (A) and full lips (B). The genes for these traits are located on different chromosomes. We are also given the phenotypes of the parents and asked to determine their genotypes, as well as the possible genotypes and phenotypes of the offspring. Additionally, we need to calculate the probability of having children with full lips and identify the law of inheritance for these traits.

Solution

To solve this problem, let's analyze the given information step by step.

1. The humped nose (A) is the dominant trait, and the straight nose is the recessive trait. The full lips (B) are the dominant trait, and the thin lips are the recessive trait.

2. The genes for these traits are located on different chromosomes. This means that the inheritance of one trait does not affect the inheritance of the other trait. Therefore, we can consider the inheritance of the humped nose and full lips separately.

3. The man has a humped nose (A) and thin lips. His mother had a straight nose and full lips. This means that the man inherited the humped nose allele (A) from his father and the thin lips allele from his mother.

- The man's genotype for the humped nose trait is Aa (heterozygous). - The man's genotype for the full lips trait is bb (homozygous recessive).

4. The woman has a straight nose and thin lips. We don't have any information about her parents, so we cannot determine her genotype for the humped nose and full lips traits. Therefore, we will consider her genotype as unknown for now.

5. Now, let's determine the possible genotypes and phenotypes of the offspring.

- The possible genotypes for the humped nose trait are AA (homozygous dominant), Aa (heterozygous), and aa (homozygous recessive). - The possible genotypes for the full lips trait are BB (homozygous dominant), Bb (heterozygous), and bb (homozygous recessive).

By combining the possible genotypes for both traits, we can determine the possible genotypes and phenotypes of the offspring.

| Genotype for Humped Nose | Genotype for Full Lips | Phenotype for Humped Nose | Phenotype for Full Lips | |-------------------------|-----------------------|--------------------------|------------------------| | AA | BB | Humped Nose | Full Lips | | AA | Bb | Humped Nose | Full Lips | | AA | bb | Humped Nose | Thin Lips | | Aa | BB | Humped Nose | Full Lips | | Aa | Bb | Humped Nose | Full Lips | | Aa | bb | Humped Nose | Thin Lips | | aa | BB | Straight Nose | Full Lips | | aa | Bb | Straight Nose | Full Lips | | aa | bb | Straight Nose | Thin Lips |

6. Finally, let's calculate the probability of having children with full lips. From the possible genotypes and phenotypes of the offspring, we can see that there are 4 out of 9 possible combinations that result in children with full lips (BB, Bb, AB, and Ab). Therefore, the probability of having children with full lips is 4/9.

7. The inheritance of these traits follows the principles of Mendelian genetics. The humped nose and full lips traits are determined by single genes located on different chromosomes. The humped nose trait follows the principle of dominant-recessive inheritance, where the dominant allele (A) masks the expression of the recessive allele (a). The full lips trait also follows the principle of dominant-recessive inheritance, where the dominant allele (B) masks the expression of the recessive allele (b).

Therefore, the inheritance of these traits can be explained by the Mendelian law of segregation and the Mendelian law of independent assortment.

Conclusion

In this problem, we analyzed the inheritance of two traits, a humped nose and full lips, which are determined by genes located on different chromosomes. We determined the genotypes of the parents, the possible genotypes and phenotypes of the offspring, and the probability of having children with full lips. We also identified that the inheritance of these traits follows the principles of Mendelian genetics, specifically the laws of segregation and independent assortment.