Question

A homozygous tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf (t) plant bearing white (r) flowers.

What is the phenotypic ratio obtained in $F_2$ generation?

Answer 1

Parent generation TTRR x ttrr

$F_1$ generation TtRr
Selfing TtRr x TtRr
$F_2$ generation

TtRr TtRr	TR	Tr	tR	tr
TR	TTRR (tall plant, red flower)	TTRr (tall plant, red flower)	TtRR (tall plant, red flower)	TtRr (tall plant, red flower)
Tr	TTRr (tall plant, red flower)	TTrr (tall plant, white flower)	TtRr (tall plant, red flower)	Ttrr (tall plant, white flower)
tR	TtRR (tall plant, red flower)	TtRr (tall plant, red flower)	ttRR (dwarf plant, red flower)	ttRr (dwarf plant, red flower)
tr	TtRr (tall plant, red flower)	Ttrr (tall plant, white flower)	ttRr (dwarf plant, red flower)	ttrr (dwarf plant, white flower)

$F_2$ generation phenotypic ratio= 9 tall plant, red flower:3 tall plant, white flower:3 dwarf plant, red flower:1 dwarf plant, white flower