Question

Помогите пожалуйста. У диких лисиц встречаются альбиносы. Их окраска рицессивна по отношению к окраске диких лисиц. От двух белых самок-альбиносов и рыжего самца родилось 8 щенят. После выращивания гибридных самок F1 спарили с самцом такого же генотипа как самки. В F2 родилось 24 щенка : а)сколько щенят в F1 будут гетерозиготными? b) сколько разных генотипов будут иметь щегки F1? с)сколько разных фенотипов по окраске было у щенят F2? d) сколько щенят в F2 могут иметь рыжий окрас и быть гетерозиготными? e) сколько щенят в F2 могли быть альбиносами?

Answer 1

а-  альбинос     А -рыжий

Р: аа * АА

г:   а    А

F1Аа (рыжие)

 

Р : Аа  *Аа

г: А  а  А  а

F2 : АА(рыж)    Аа(рыж )   Аа(рыж)   аа(альб)

в F1 гетерозиготы  100 процентов. т.е. все.  генотипы одинаковы у всех.

в F2  фенотипов по окраске было : рыжый и альбинос

рыжие и гетерозиготные - 50 прцентов

альбиносы - 25 процентов

Answer 2

1)два типа: "A" и "а"

2)один тип - "а"

3)два: длино- и короткошерстные

4)вероятнее всего 4 котенка

Answer 3

Albinism in Wild Foxes

Wild foxes can indeed exhibit albinism, where their fur coloration is recessive compared to that of regular wild foxes. Albinism is a genetic condition characterized by a lack of pigmentation in the hair, skin, and eyes. In the case mentioned, two white female albino foxes and one red male fox produced a litter of 8 puppies. Let's analyze the questions one by one.

a) How many puppies in F1 will be heterozygous? To determine the number of heterozygous puppies in F1, we need to consider the genotypes of the parents. The two white female albino foxes are homozygous recessive (aa) for albinism, and the red male fox is homozygous dominant (AA) for regular pigmentation. When these parents are crossed, all the puppies in F1 will be heterozygous (Aa) for albinism. Therefore, all 8 puppies in F1 will be heterozygous.

b) How many different genotypes will the F1 puppies have? Since both the white female albino foxes are homozygous recessive (aa) and the red male fox is homozygous dominant (AA), all the puppies in F1 will have the genotype Aa. Therefore, there will be only one genotype in the F1 puppies.

c) How many different phenotypes did the F2 puppies have in terms of fur coloration? To determine the number of different phenotypes in F2, we need to consider the genotypes of the F1 puppies. Since all the F1 puppies have the genotype Aa, they will have the same phenotype, which is a regular pigmentation. Therefore, all the F2 puppies will have the same phenotype in terms of fur coloration.

d) How many F2 puppies can have a red fur color and be heterozygous? To determine the number of F2 puppies that can have a red fur color and be heterozygous, we need to consider the possible genotypes. In F2, the possible genotypes are AA, Aa, and aa. Among these genotypes, only the heterozygous genotype Aa can have a red fur color. Therefore, half of the F2 puppies (12 out of 24) can have a red fur color and be heterozygous.

e) How many F2 puppies could be albino? To determine the number of F2 puppies that could be albino, we need to consider the possible genotypes. In F2, the possible genotypes are AA, Aa, and aa. Among these genotypes, only the homozygous recessive genotype aa can be albino. Therefore, none of the F2 puppies can be albino.

Please let me know if you have any further questions!