Question

In a homozygous plant round seeds (R) are dominant over wrinkled seeds (r) : Draw a Punnett square to show the gametes and offspring when both the plants have heterozygous round seeds (Rr).

Answer 1

The cross is as follows :
Parents :  Rr (Round) x  Rr (Round)
Gametes :  Rr
Punnett square :
Both plants are with heterozygous round seeds (Rr)

Gametes	R	r
R	RR (Homozygous round seeds)	Rr (Heterozygous round seeds)
r	Rr (Heterozygous round seeds)	rr (Homozygous wrinkled seeds)

Therefore the ratio will be 1 (homozygous round) : 2 (heterozygous round) : 1 (wrinkled)