Science (086) — CBSE Class 10 board question

(i) In F₁ progeny, all plants will have violet flowers (like the dominant parent). The white flower trait (recessive) will not appear; all offspring show only the dominant character.

(ii) In F₂ progeny, both violet-flowered and white-flowered plants will appear in the ratio 3:1 (3 violet : 1 white). The recessive trait (white flower) reappears.

(iii) In a 3:1 ratio, 25 plants out of 100 will show the recessive trait (white flowers).

• This is a standard Mendelian monohybrid cross question. F₁ shows only the dominant trait; F₂ gives a 3:1 phenotypic ratio.
• Examiners expect you to clearly state "all violet" for F₁, the 3:1 ratio for F₂, and the calculation (100 × 1/4 = 25) for part (iii).
• Key terms: dominant, recessive, F₁, F₂, 3:1 ratio — use them explicitly.