Question

With the help of a diagram (Punnett square) show a Mendelian experiment where tall pea plant bearing red flowers is crossed with a short pea plant bearing white flowers. Write both the phenotypic and genotypic ratio for F2 generation.

Answer 1

Parents TTRR ttrr

Tall Red X Short White

↓

F1 generation TtRr X TtRr ( Selfing)

Tall red Tall red

F2 generation

Gametes		TR		Tr		tR		tr
TR		TTRR Tall red		TTRr Tall red		TtRr Tall red		TtRr Tall red
Tr		TTRr Tall red		Ttrr Tall white		TtRr Tall red		Ttrr Tall white
tR		TtRR Tall red		TtRr Tall red		ttRR Short red		ttRr Short red
tr		TtRr Tall red		Ttrr Tall white		ttRr Short red		ttrr Short white

The phenotypic ratio: 9 tall red : 3 tall white : 3 short red : 1 short white.

The genotypic ratio: 1 TTRR : 4 TtRr : 1 TTrr : 1 ttRR : 2 TtRR : 2 TTRr : 2 ttRr : 2 Ttrr : 1 ttrr.