Question

Explain the difference in inheritance pattern of flower colour in garden pea plant and snap-dragon plant with the help of monohybrid crosses.

Answer 1

Flower colour inheritance (Pea vs Snapdragon): Purple flowers predominate over white flowers in pea plants, which exhibit Mendelian inheritance in floral color.

	P	p
P	PP (Purple flower)	Pp (Purple flower)
p	Pp (Purple flower)	pp (White flower)

Phenotypic ratio:

Purple : White
3 : 1

Genotypic ratio:

PP : Pp : pp

1 : 2 : 1

Snapdragons exhibit partial dominance in blossom color, with pink (Rr) offspring produced in F₁ when red (RR) and white (rr) plants are crossed.

	R	r
R	RR (Red flower)	Rr (Pink flower)
r	Rr (Pink flower)	rr (White flower)

Phenotypic ratio:

Red : Pink : White
1 : 2 : 1

Genotypic ratio:

RR : Rr : rr

1 : 2 : 1