CBSE Class 10 Answered
Hi Sahil,
1. The genotype of the plant heterozygous tall with red flowers is TtRr.
On self-pollination,
Parents: TtRr × TtRr
Gametes: TR, tR, Tr, tr
Progeny:
|
TR |
tR |
Tr |
tr |
TR |
TTRR |
TtRR |
TTRr |
TtRr |
tR |
TtRR |
ttRR |
TtRr |
ttRr |
Tr |
TTRr |
TtRr |
TTrr |
Ttrr |
tr |
TtRr |
ttRr |
Ttrr |
ttrr |
So, 25% of the progeny is heterozygous for the trait.
Now, out of 2000 seeds, the number of seeds that are heterozygous for the trait = 25% of 2000 = 500.
Hence, 500 seeds would be heterozygous for the trait.
2. Genotype
Pure tall plant with green pod: TTYY
Pure short plant with yellow pod: ttyy
Gametes: TY, ty
Progeny in F1 generation : TtYy
Self-pollination of F1 generation: TtYy × TtYy
Gametes: TY, tY, Ty, ty
Progeny in F2 generation:
|
TY |
tY |
Ty |
ty |
TY |
TTYY |
TtYY |
TTYy |
TtYy |
tY |
TtYY |
ttYY |
TTYy |
ttYy |
Ty |
TTYy |
TtYy |
TTyy |
Ttyy |
ty |
TtYy |
ttYy |
Ttyy |
ttyy |
So, out of 16 progeny, 4 progeny would be short.