NEETZoologyPrinciples of Inheritance and Variation
A pea plant with yellow and round seeds is self-pollinated. It produces a progeny consisting of only yellow-round and green-round plants. What fraction of this total progeny will be homozygous for both seed colour and seed shape?
Options
- A1 2
- B1 4
- C1 8
- D1 16
Correct answer
A. 1 2
Step-by-step solution
Since the self-pollinated parent with yellow and round seeds produces both yellow and green seeds in the progeny, it must be heterozygous for seed colour (Yy). Since it produces only round seeds, it must be homozygous dominant for seed shape (RR). Therefore, the genotype of the parent plant is YyRR. When YyRR is self-pollinated (YyRR YyRR), the progeny genotypes will be: 1 4 YYRR 1 2 YyRR 1 4 yyRR The plants homozygous for both traits are YYRR and yyRR. Total fraction = 1 4 + 1 4 = 1 2 . Answer: 1 2