Question

Мужчина с полидактилией вступил в брак с женщиной ,у которой отсуствуют малые коренные зубы. в семье родился ребенок не имеющий вышеуказанных аномалий. у человека отсуствие малых коренных зубов и полидактилия являются доминантнвми признаками и наследуются независимо. сколько типов гамет образуется у женщины?

Answer 1

Если я правильно понимаю, то две. aB и ab
(A-Полидактилия
а-отсутствие полидактилии
B-отсутствие моляров
b-наличие моляров)

Answer 2

Inheritance of Dominant Traits in Humans

When a man with polydactyly (extra fingers or toes) marries a woman who lacks small molars, and they have a child without these anomalies, it suggests that the absence of small molars and polydactyly are both dominant traits that are inherited independently. To determine the number of gamete types formed by the woman, we need to understand the inheritance patterns of these traits.

In humans, each individual has two copies of each gene, one inherited from each parent. Dominant traits are expressed when at least one copy of the gene is dominant, while recessive traits are only expressed when both copies of the gene are recessive.

Polydactyly: Polydactyly is a condition characterized by the presence of extra fingers or toes. It is caused by a dominant gene, meaning that only one copy of the gene is needed for the trait to be expressed. Therefore, an individual with polydactyly can have either one or two copies of the polydactyly gene.

Absence of Small Molars: The absence of small molars is also considered a dominant trait. This means that only one copy of the gene for small molars is needed for the trait to be absent. Therefore, an individual without small molars can have either one or two copies of the gene for small molars.

Based on the information provided, the man has polydactyly and the woman lacks small molars. Since both traits are dominant and inherited independently, we can determine the number of gamete types formed by the woman using the rule of multiplication.

The rule of multiplication states that the number of possible gamete types is equal to 2 raised to the power of the number of heterozygous gene pairs. In this case, the woman is heterozygous for both traits, as she does not have polydactyly (PP or Pp) and lacks small molars (MM or Mm).

Therefore, the woman can form four types of gametes: PM, Pm, pM, and pm.

It is important to note that this calculation assumes that the genes for polydactyly and small molars are not linked and are located on different chromosomes. If the genes were linked, the number of possible gamete types would be different.

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