Question

Привет всем)))Помогите пожалуйста решить)))Заранее большое спасибо)))Главное покажите решение)) 24. У томатов гладкая кожица плодов является доминантным признаком по отношению к опушенной. Гомозиготную форму с неопушенными плодами скрестили с растением с опушенными плодами и получили 12 потомков. От них после самоопыления получили в F2 88 растений.а) Сколько типов гамет образует растение с опушенными плодами? б) Сколько гетерозиготных растений будет в F1? в) Сколько растений с гладкими плодами будет в F1? г) Сколько растений будет с опушенными плодами в F2? д) Сколько разных генотипов в F2?

Answer 1

Решение во вложении:                                   

Answer 2

Problem Analysis

In this problem, we are given that smooth skin in tomatoes is a dominant trait over hairy skin. We are also given that a homozygous smooth tomato plant is crossed with a hairy tomato plant, and 12 offspring are obtained. From these offspring, 88 plants are obtained in the F2 generation after self-pollination. We need to determine the number of gamete types produced by the hairy tomato plant, the number of heterozygous plants in the F1 generation, the number of plants with smooth skin in the F1 generation, the number of plants with hairy skin in the F2 generation, and the number of different genotypes in the F2 generation.

Solution

a) To determine the number of gamete types produced by the hairy tomato plant, we need to consider the genotype of the hairy tomato plant. Since smooth skin is a dominant trait, the genotype of the hairy tomato plant must be heterozygous (Ss), where S represents the smooth allele and s represents the hairy allele. In this case, the hairy tomato plant will produce two types of gametes: one with the smooth allele (S) and one with the hairy allele (s). Therefore, the number of gamete types produced by the hairy tomato plant is 2.

b) To determine the number of heterozygous plants in the F1 generation, we need to consider the cross between the homozygous smooth tomato plant (SS) and the heterozygous hairy tomato plant (Ss). When these two plants are crossed, all the offspring in the F1 generation will be heterozygous (Ss) because the smooth allele (S) is dominant over the hairy allele (s). Since we obtained 12 offspring in the F1 generation, the number of heterozygous plants in the F1 generation is 12.

c) To determine the number of plants with smooth skin in the F1 generation, we need to consider the genotype of the offspring in the F1 generation. As mentioned earlier, all the offspring in the F1 generation will be heterozygous (Ss). Since smooth skin is a dominant trait, all the heterozygous plants will have smooth skin. Therefore, the number of plants with smooth skin in the F1 generation is 12.

d) To determine the number of plants with hairy skin in the F2 generation, we need to consider the genotype of the offspring in the F2 generation. In the F2 generation, the heterozygous plants (Ss) from the F1 generation will undergo self-pollination. When heterozygous plants are self-pollinated, they can produce offspring with either smooth skin (SS), heterozygous (Ss), or hairy skin (ss). According to Mendel's law of segregation, the ratio of the genotypes in the F2 generation will be 1:2:1 for SS:Ss:ss. Since we obtained 88 plants in the F2 generation, the number of plants with hairy skin in the F2 generation is 88.

e) To determine the number of different genotypes in the F2 generation, we need to consider the possible combinations of alleles. In the F2 generation, the possible genotypes are SS, Ss, and ss. According to Mendel's law of segregation, the ratio of the genotypes in the F2 generation will be 1:2:1 for SS:Ss:ss. Since we obtained 88 plants in the F2 generation, the number of different genotypes in the F2 generation is 3.

Summary

a) The plant with hairy skin will produce 2 types of gametes. b) The number of heterozygous plants in the F1 generation is 12. c) The number of plants with smooth skin in the F1 generation is 12. d) The number of plants with hairy skin in the F2 generation is 88. e) The number of different genotypes in the F2 generation is 3.

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