Question

3. Решите задачу. У флоксов белая окраска венчика доминирует над розовой. Скрестили гетерозиготное растение с белыми цветками и растение с розовыми цветками и получили 96 гибридов. а) Сколько типов гамет образует растение с розовыми цветками? б) Сколько растений с розовыми цветками будет в F1? в) Сколько разных генотипов будет в F1? г) Сколько разных фенотипов будет в F1? д) Сколько растений с белыми цветками будет в F1?

Answer 1

А – белая окраска, а – розовая окраска. Генотип одного растения А.. – белый, второго аа – розовый.
Так как в первом поколении наблюдается расщепление 1:1 (51:45) => генотип первого растения Аа.
1. Аа и аа.
2. 2
3. 1
4. 3 с белым венчиком:1 с розовым венчиком.

Answer 2

Problem Analysis

To solve this problem, we need to understand the principles of inheritance and genetic crosses. We are given that white color in the flox flowers is dominant over pink color. We also know that we crossed a heterozygous plant with white flowers with a plant with pink flowers and obtained 96 hybrids. We need to determine the number of gamete types produced by the plant with pink flowers, the number of plants with pink flowers in the F1 generation, the number of different genotypes in the F1 generation, the number of different phenotypes in the F1 generation, and the number of plants with white flowers in the F1 generation.

Solution

a) The plant with pink flowers is homozygous recessive (pp) because the white color is dominant. In this case, there is only one type of gamete produced by the plant with pink flowers, which is p. Therefore, the number of gamete types is 1.

b) In the F1 generation, all the hybrids will have white flowers because the white color is dominant. Therefore, there will be 0 plants with pink flowers in the F1 generation.

c) To determine the number of different genotypes in the F1 generation, we need to consider the possible combinations of alleles from the parent plants. The heterozygous plant with white flowers can produce two types of gametes, W and w. The homozygous recessive plant with pink flowers can produce only one type of gamete, p. Therefore, the possible genotypes in the F1 generation are Wp and wp. There are two different genotypes in the F1 generation.

d) The number of different phenotypes in the F1 generation is determined by the number of different genotypes. Since there are two different genotypes (Wp and wp) in the F1 generation, there will be 2 different phenotypes.

e) To determine the number of plants with white flowers in the F1 generation, we need to consider the possible genotypes. In the F1 generation, there will be two genotypes: Wp and wp. Both genotypes have the dominant allele for white flowers (W). Therefore, all the plants in the F1 generation will have white flowers. Therefore, the number of plants with white flowers in the F1 generation is equal to the total number of hybrids, which is 96.

Summary

a) The plant with pink flowers will produce 1 type of gamete. b) There will be 0 plants with pink flowers in the F1 generation. c) There will be 2 different genotypes in the F1 generation. d) There will be 2 different phenotypes in the F1 generation. e) There will be 96 plants with white flowers in the F1 generation.

Please let me know if anything is unclear or if you have any further questions!