Question

Sol.(b) [Key Concept: Mendel's Discrete Factors — Experimental Basis] Mendel's proposal that factors (genes) are DISCRETE and INDEPENDENT was based on the observation that offspring of crosses between plants with two CONTRASTING characters showed ONLY ONE CHARACTER without any blending — the dominant character appeared in its pure form in F1. There was no intermediate/blended phenotype. This pure expression (no blending) indicated that the factors are discrete units that remain intact and don't mix. The reappearance of recessive traits in F2 (from F1 self-pollination) further confirmed discrete factors.

Phenotypic ratio Round:Round:Wrinked:Wrinked

Yellow green yellow green

9 : 3 : 3 : 1

Genotypic ratio 1 : 2 : 2 : 4 : 1 : 2 : 1 : 2 : 1

Results of a dihybrid cross where the two parents differed in two pairs of contrasting. Rest of the option does no support the Mendel’s law of segregation.