Question

Two pea plants, one with round green seeds (RRyy) and another with wrinkled yellow seeds (rrYY) produce F1 progeny that have round yellow seeds. When F1 plants are selfed, the F2 progeny will have new combinations of characters. Choose the new combination of characters from the following:

i. Round and yellow seeds
ii. Round and green seeds
iii. Wrinkled and yellow seeds
iv. Wrinkled and green seeds

• A. i and ii
• B. i and iv
• C. ii and iii
• D. i and iii

Answer 1

The correct option is B i and iv

From the given information, it is clear that this is a typical dihybrid cross, where two characters, colour of the seeds (green or yellow) and shape of the seeds (round or wrinkled) are considered at a time. In a typical dihybrid cross, when F1 plants are selfed, one gets the two parental combinations and two new combinations in the ratio 9:3:3:1.

In the given example, the combination would be:

Round and green seeds: 9
Round and yellow seeds: 3
Wrinkled and green seeds: 3
Wrinkled and yellow seeds: 1

So, Round & yellow seeds and wrinkled & green seeds are the two new combinations.