Question

In $F_2$ generation, 960 garden pea pods are produced by a cross due to self pollination of heterozygous parents. How many pods would be green and inflated?

• A. 180
• B. 60
• C. 540
• D. 240

Answer 1

The correct option is C 540

In pea plant, yellow and constricted pods are recessive to green and full/inflated pods. Since the question is about the inheritance of two different traits (pod color and pod shape) at a time; it is a dihybrid cross. Hence, the phenotypic ratio for $F_2$ generation of a dihybrid cross will be 9 green and inflated pods: 3 green and constricted pods: 3 yellow and inflated pods: 1 yellow and constricted pods. According to the question, out of total 960 plants, the number of plants with green and inflated pods will be = 9/16 $\times$960 = 540. This makes option C correct answer.
Option A is incorrect as 180 plants out of 960 will have either yellow and inflated pods or green and constricted pods since 3/16 $\times$ 960 = 180.
Option B is incorrect as 60 plants out of 960 will have yellow and constricted pods since 1/16 $\times$ 960 = 60.
Option D does not signify any $F_2$ generation phenotypic ratio for a Mendelian dihybrid cross.
Therefore, the correct answer is option C.