Question

при схрещуванні дрозофіл із нормальними крилами (А) в потомстві з'явилось 1/4 мух із загнутими крилами (а). Їх схрестили з нормальними мухами й отримали 47 особин із нормальними крилами й 49 - із загнутими. Визначте генотип мух, яких схрещували в обох дослідах​

Answer 1

Ответ:

Дано:

А - нормальные крылья

а - загнутые крылья

Решение:

1.

Р. Аа * Аа       -  генотип родителей (1)

G: А,а  А,а

F1: АА : 2Аа : аа, где 3/4 нормальные крылья (АА/Аа) и 1/4 с загнутыми крыльями (аа)

2.

Р. аа * Аа   -  генотип родителей (2)

G: а     А,а

F2: Аа : аа , где 50% (47 шт)  с нормальными крыльями (Аа) и 50% (49 шт)  с загнутыми крыльями (аа)

Answer 2

Background Information

In this scenario, we are dealing with the inheritance of wing shape in fruit flies (Drosophila). The wing shape is determined by a single gene with two alleles: the normal allele (A) for straight wings and the mutant allele (a) for bent wings. We need to determine the genotypes of the flies involved in the crosses and the mode of inheritance for wing shape.

Cross 1: Cross between Drosophila with normal wings (A) and Drosophila with bent wings (a)

When Drosophila with normal wings (A) is crossed with Drosophila with bent wings (a), the offspring show a 1:1 ratio of normal wings to bent wings. This indicates that the allele for normal wings (A) is dominant over the allele for bent wings (a).

Cross 2: Cross between the F1 generation (Aa) and Drosophila with normal wings (A)

In the second cross, the F1 generation (Aa) flies with normal wings are crossed with Drosophila with normal wings (A). The resulting offspring show a 1:1 ratio of normal wings to bent wings. This indicates that the allele for normal wings (A) is dominant over the allele for bent wings (a).

Determining the Genotypes

Based on the information provided, we can determine the genotypes of the flies involved in the crosses as follows:

- Cross 1: - Drosophila with normal wings (A) x Drosophila with bent wings (a) - Offspring: 1/4 flies with bent wings (aa) and 3/4 flies with normal wings (Aa) - Cross 2: - F1 generation (Aa) x Drosophila with normal wings (A) - Offspring: 47 flies with normal wings (AA or Aa) and 49 flies with bent wings (aa)

Therefore, the genotypes of the flies involved in the crosses are as follows:

- Cross 1: - Drosophila with normal wings (A): Aa - Drosophila with bent wings (a): aa - Cross 2: - F1 generation (Aa): Aa - Drosophila with normal wings (A): AA or Aa

Please note that the genotypes are based on the assumption that wing shape is determined by a single gene with two alleles and that the allele for normal wings (A) is dominant over the allele for bent wings (a).