Q1. [1] § Introduction § 8.2.2 Rules for the Inheritance of Traits – Mendel's Contributions § 8.2.3 How do these Traits get Expressed?
When a pure-tall pea plant is crossed with a pure-dwarf pea plant, the percentage of tall pea plants in F₁ and F₂ generation pea plants will be respectively :
- (a) 100% ; 25%
- (b) 100% ; 50%
- (c) 100% ; 75%
- (d) 100% ; 100%
Previously asked in CBSE board exam
2025 31/4/1 Q9
Generated by claude-sonnet-4-6 · 2026-06-15 06:53 · grounding rag
Model Answer
(c) 100% ; 75%
When pure-tall (TT) is crossed with pure-dwarf (tt), all F₁ plants are Tt (tall) = 100% tall. In F₂, ratio is 1TT : 2Tt : 1tt, giving 3 tall : 1 dwarf = 75% tall.
Explanation
Remember: tall is dominant over dwarf. F₁ gives 100% tall (all Tt). In F₂, self-crossing Tt × Tt gives the classic 3:1 Mendelian ratio — 75% tall, 25% dwarf. This is the foundational result of Mendel's monohybrid cross.
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