Question

Пожалуйста умоляю помогите мне задаю 3 раз вопрос везде! Мне нужна помощ по биологиия! очень сильно! Помогитееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееееее У кур нормальное оперение доминирует над шелковистым.От двух нормальных по фенотипу гетерозигот получено 108 цыплят. 1)Сколько из них ожидается нормальных цыплят ? 2)Сколько шелковистых? 3)Сколько цыплят F1 гомозиготных? 4)Сколько разных фенотипов имеют цыплята в F1? 5)сколько типов гамед образует самка и самец? Там надо вместе с дано решщение!

Answer 1

Дано
ген        признак
А          нормальное оперение
а          шелковистое оперение
----------------------------------------------------

РЕШЕНИЕ

Р       Аа     х    Аа
G     А  а         А   а
F1    АА    Аа      Аа       аа
        нор   нор    нор      шел

ответ:
1) 81 нормальных
2) 27 шелковистых
3) 27 гомозигот по доминантному признаку (АА), 27 гомозигот по рецессивному признаку (аа)
4) (АА и Аа - нормальные), (аа - шелковистые), фенотипов  -2
5) самка и самец образуют 2 типа гамет (А)   и    (а), так как они гетерозиготные.

 

Answer 2

Background Information

In this question, we are given information about the dominance of normal plumage over silky plumage in chickens. From two heterozygous individuals, 108 chicks were obtained.

Solution

To solve this problem, we need to use the principles of Mendelian genetics. Let's go through each question step by step.

1) How many normal chicks are expected? Since normal plumage is dominant over silky plumage, we can assume that the heterozygous individuals (Nn) will produce both normal (N) and silky (n) offspring. According to Mendelian genetics, when two heterozygous individuals are crossed, the expected phenotypic ratio is 3 normal:1 silky. Therefore, we can calculate the number of normal chicks using the following formula:

Number of normal chicks = (3/4) * Total number of chicks

Substituting the given value of 108 chicks:

Number of normal chicks = (3/4) * 108 = 81

Therefore, 81 normal chicks are expected.

2) How many silky chicks are expected? Using the same principle as above, we can calculate the number of silky chicks using the formula:

Number of silky chicks = (1/4) * Total number of chicks

Substituting the given value of 108 chicks:

Number of silky chicks = (1/4) * 108 = 27

Therefore, 27 silky chicks are expected.

3) How many F1 chicks are homozygous? Since we are given that the original parents are heterozygous (Nn), the F1 generation will have both heterozygous (Nn) and homozygous (NN) individuals. The number of homozygous chicks can be calculated using the formula:

Number of homozygous chicks = (1/4) * Total number of chicks

Substituting the given value of 108 chicks:

Number of homozygous chicks = (1/4) * 108 = 27

Therefore, 27 F1 chicks are homozygous.

4) How many different phenotypes do the F1 chicks have? In the F1 generation, there are two possible phenotypes: normal (N) and silky (n). Therefore, the F1 chicks have two different phenotypes.

5) How many types of gametes are formed by the female and male? To determine the number of gamete types formed by the female and male, we need to consider the genotype of each parent. Since the female and male are both heterozygous (Nn), they will produce two types of gametes each (one with the N allele and one with the n allele). Therefore, the female and male together form four types of gametes.

In summary: 1) The expected number of normal chicks is 81. 2) The expected number of silky chicks is 27. 3) The number of F1 chicks that are homozygous is 27. 4) The F1 chicks have two different phenotypes. 5) The female and male together form four types of gametes.

Please let me know if you have any further questions!