Question

.У свиней біла щетина і коротконогість – домінантні ознаки, а чорна щетина і ноги нормальної довжини – рецесивні ознаки. На свинофермі від схрещування білого кнура з короткими ногами і чорних свиноматок, у яких теж короткі ноги, все потомство було білим, але 86 поросят були коротконогими і 27 поросят мали ноги нормальної довжини. Визначити генотипи батьківських форм.

Answer 1

Большими римскими цифрами в кружочке обозначены номера страниц. Надеюсь не запутаешься)

Answer 2

Genetic Inheritance in Pigs

In this scenario, we are dealing with genetic inheritance in pigs, specifically focusing on the dominant and recessive traits of white hair and short legs, and black hair and normal leg length.

Given Information: - White hair and short legs are dominant traits, while black hair and normal leg length are recessive traits. - When a white boar with short legs is crossed with black sows with short legs, and all the offspring are white, but 86 piglets have short legs and 27 have normal leg length.

Determining the Genotypes of the Parental Forms

To determine the genotypes of the parental forms, we can use the following genetic symbols: - W: Dominant allele for white hair - w: Recessive allele for black hair - S: Dominant allele for short legs - s: Recessive allele for normal leg length

The white boar with short legs can be represented as WSS and the black sows with short legs can be represented as wSs.

Offspring's Genotypes

The offspring's genotypes can be determined using a Punnett square to represent the possible combinations of alleles from the parental forms.

When the white boar with short legs (WSS) is crossed with the black sows with short legs (wSs), the possible genotypes of the offspring are as follows:

- All offspring are white, indicating that they all carry at least one dominant allele for white hair (W). - 86 piglets have short legs, indicating that they inherited at least one dominant allele for short legs (S). - 27 piglets have normal leg length, indicating that they inherited two recessive alleles for normal leg length (ss).

Conclusion

Based on the distribution of the offspring's traits, we can deduce the genotypes of the parental forms: - The white boar with short legs has the genotype WSS. - The black sows with short legs have the genotype wSs.

This conclusion is consistent with the observed phenotypes of the offspring and the principles of genetic inheritance.