When red and white flowered parents of snapdragon were crossed, the phenotypic ratio of \(F_2\) generation would be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 1 : 2 : 1
Option (2) 1 : 2 : 1 — Correct. In snapdragon, RR is red, Rr is pink and rr is white (incomplete dominance). Crossing red with white gives pink F1 (Rr); selfing these gives RR : Rr : rr = 1 : 2 : 1, that is red : pink : white = 1 : 2 : 1.
NCERT Extract:
Incomplete Dominance – “… In a cross between true-breeding red-flowered (RR) and truebreeding white-flowered plants (rr), the F1 (Rr) was pink (Figure 4.6). When the F1 was self-pollinated the F2 resulted in the following ratio 1 (RR) Red : 2 (Rr) Pink : 1 (rr) White.”
