In a dihybrid cross between two heterozygous pea plants for seed shape (Rr) and seed colour (Yy), what is the probability that a seed from the F1 generation is round and green?
Answer
3/16
The correct answer is 3/16 — Because the two genes assort independently, the probability of round and green is (3/4) × (1/4) = 3/16.
Step-by-step solution
- The seed shape gene Rr segregates into R and r with probabilities ½ each.
- For a round phenotype (R), the possibilities are RR or Rr; the combined probability is 3/4.
- The seed colour gene Yy segregates into Y and y with probabilities ½ each.
- For a green phenotype (y), the probability is 1/4.
- Because the two genes assort independently, the probability of round and green is (3/4) × (1/4) = 3/16.
Common mistake: Multiplying probabilities incorrectly or ignoring the independence
Concept tested: Independent assortment
Published · How this solution was prepared and checked
← All Principles of Inheritance and Variation questions