Q1. [1] § Introduction § 8.1 ACCUMULATION OF VARIATION DURING REPRODUCTION § 8.2.3 How do these Traits get Expressed?
The genotype of green stemmed tomato plant is denoted by 'GG' and that of purple stemmed tomato plant as 'gg'. Hybrid of a cross between these two were self-pollinated to obtain F2 progeny. What will be the ratio of GG, Gg and gg in this F2 progeny ?
- (A) 2:1:1
- (B) 3:1:0
- (C) 1:1:2
- (D) 1:2:1
Previously asked in CBSE board exam
2026 31/2/1 Q1
Generated by claude-sonnet-4-6 · 2026-06-15 06:51 · grounding rag
Model Answer
(D) 1:2:1
F1 hybrid is Gg. On self-pollination: GG : Gg : gg = 1 : 2 : 1.
Explanation
F1 cross is Gg × Gg. The Punnett square gives GG, Gg, Gg, gg — ratio 1:2:1. This is the standard monohybrid F2 genotypic ratio examiners expect students to recall directly.
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