NEETZoologyPrinciples of Inheritance and Variation
A pea plant heterozygous for round seeds is crossed with a plant producing wrinkled seeds. If a total of 120 seeds are collected from this cross, what is the expected number of wrinkled seeds among the progeny?
Options
- A90
- B30
- C120
- D60
Correct answer
D. 60
Step-by-step solution
The cross is between a heterozygous round seed plant ( Rr ) and a homozygous recessive wrinkled seed plant ( rr ). This is a test cross: Rr rr . The expected progeny will have genotypes Rr (round) and rr (wrinkled) in a 1:1 ratio. Therefore, half of the progeny is expected to have wrinkled seeds. Expected number of wrinkled seeds = 1 2 120 = 60 . Answer: 60