1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# A genetically dwarf plant starts growing and becomes a tall plant after application of plant growth hormones. This genetically dwarf plant was crossed with a pure line tall plant and the resulting F1 hybrid was self-pollinated. What will be the phenotype of the F2 generation?

A
All will be dwarf plants
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
B
All will be tall plants
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
C
50% will be dwarf and 50% will be tall
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
D
25% will be dwarf and 75% will be tall
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution

## The correct option is D 25% will be dwarf and 75% will be tallThe genetically dwarf plant (tt) grew tall after its treatment with growth hormones. However, genetically, it is a dwarf plant. Hence, the gametes produced by this plant carried ' t 'allele for the character, height. This dwarf plant was crossed with a pure line tall plant. Hence, the gametes produced by the pure line tall plant carried T allele for height. When these plants are crossed, all the F1 hybrids are tall (Tt). When the F1 hybrids are self-pollinated, then the tall and dwarf plants are produced in the ratio of 3 : 1 (tall : dwarf). ⇒ Out of 4 plants, no. of dwarf plants = 1 ⇒ Out of 100 plants, no. of dwarf plants =(14)×100=25 Hence, 25% of plants in the F2 generation will be dwarf. ⇒ Out of 4 plants, no. of tall plants = 3 ⇒ Out of 100 plants, no. of tall plants =(34)×100=75 Hence, 75% of plants in the F2 generation will be tall.

Suggest Corrections
0
Join BYJU'S Learning Program
Related Videos
Mendel's Experiment
BIOLOGY
Watch in App
Explore more
Join BYJU'S Learning Program