Question

A pea plant with genotype YyRr is crossed with another pea plant with genotype yyrr. The expected phenotypic ratio of individuals formed will be ...............

• A. 2:1:1
• B. 1:2:1
• C. 1:1:2
• D. 1:1:1:1

Hint:

In a dihybrid cross, the offspring often exhibit a 1:1:1:1 phenotypic ratio, particularly in cases involving heterozygous and homozygous traits.

Answer 1

The Correct Option is D

Step 1: Understanding the cross.
The cross involves a pea plant with genotype YyRr and another with genotype yyrr. The possible genotypes of the offspring are determined by performing a dihybrid cross.
Step 2: Analyzing the options.
(A) 2:1:1: Incorrect. This does not correspond to the correct phenotypic ratio.
(B) 1:2:1: Incorrect. This ratio does not represent the expected outcome of the cross.
(C) 1:1:2: Incorrect. This is not the correct phenotypic ratio for this dihybrid cross.
(D) 1:1:1:1: Correct. This is the correct phenotypic ratio resulting from the cross, which produces four different phenotypes in a 1:1:1:1 ratio.
Step 3: Conclusion.
The correct answer is (D) 1:1:1:1, as this is the expected phenotypic ratio for the given dihybrid cross.