Question

A tall pea plant with round seeds (TTRR) is crossed with a short pea plant with wrinkled seeds (ttrr). The \( F_1 \) generation will be:

• A. 25% tall with round seeds
• B. 50% tall with wrinkled seeds
• C. 75% tall with wrinkled seeds
• D. 100% tall with round seeds

Hint:

In dihybrid crosses, dominant traits will always appear in the F1 generation if at least one dominant allele is present.

Answer 1

The Correct Option is D

In this problem, we are dealing with a dihybrid cross between pea plants. The gene for plant height (T for tall, t for short) and the gene for seed shape (R for round, r for wrinkled) are both inherited independently. The parent plants are:
- Tall with round seeds: TTRR
- Short with wrinkled seeds: ttrr
Using the Punnett square for this cross:
- The tall parent (TTRR) will produce gametes: TR.
- The short, wrinkled parent (ttrr) will produce gametes: tr.
Thus, all the F1 generation will inherit one dominant T allele for height and one dominant R allele for seed shape, making them all tall with round seeds. Thus, the correct answer is (D) 100% tall with round seeds.