In Mendel’s dihybrid cross, a tall plantbearing red flowers (TTRR) is crossed with a dwarf plant bearing yellow flowers (ttrr). On the basis of this cross, answer the following questions : 1) Write the gametes formed by the P1 generation?
Answers
Answer:Dihybrid cross is a cross between two different genes that have two different traits. When a tall plant with red colored flower (TTRR) is crossed with dwarf plant with white colored flower (ttrr), the F
1
generation will have all tall plants with red colored flowers (TtRr). When F
1
generation is crossed, the F
2
generation will have phenotype in the ratio of 9:3:3:1 where 9 parts will be tall plants with red colored flowers, 3 parts will be tall plants with white colored flowers, 3 parts will be dwarf plants with red colored flowers and 1 part will be dwarf plant with white flower. The genotypic ratio will be 1:2:1:2:4:2:1:2:1. In this, frequency of TtRR genotype will be 12.5%, frequency of ttrr genotype will be 6.25%, frequency of TTRR genotype will be 6.25%, frequency of ttRr genotype will be 12.5%, frequency of Ttrr will be 12.5%, frequency of ttRr will be 12.5%, frequency of ttRR will be 6.25%, frequency of TtRr will be 25% and frequency of TTrr will be 6.25%.
Thus, the correct answer is 'Frequency of ttRr genotype = 25 %.'
Explanation: