Answer:
a. Genotype in F1 - TtBb
Phenotype in F1 - tough pods, bush-type growth
b. Proportion of F2 that are heterozygous for bush-type growth form = 5/8
c. Proportion of the F2 with tender pods = 1/4
d. Proportion of F2 that are heterozygous for growth form and have tender pods = 1/8
Explanation:
Since the two traits are located on different chromosomes, they will independently assort during gametes formation. T is dominant over t and B is dominant over b.
Two true-breeding varieties were crossed at the beginning of the program:
TTBB x ttbb
All F1 plants will have the genotype TtBb with tough pods and bush-type growth form.
Advancing the cross to F2:
TtBb x TtBb
Progeny
1 TTBB - tough pods, bush-type
2 TTBb - tough pods, bush-type
2 TtBB - tough pods, bush-type
4 TtBb - tough pods, bush-type
1 TTbb - tough pods, climbing-type
2 Ttbb - tough pods, climbing-type
1 ttBB - tender pods, bush-type
2 ttBb - tender pods, bush-type
1 ttbb - tender pods, climbing-type
<em>Proportion of F2 that are heterozygous for bush-type growth form = 10/16 = 5/8</em>
<em>Proportion of the F2 with tender pods = 4/16 = 1/4</em>
<em>Proportion of F2 that are heterozygous for growth form and have tender pods = 2/16 = 1/8</em>
