Question

If a dwarf plant is treated with gibberellins it becomes tall and this plant now cross with pure tall plant then proqeny of first generation F${}_1$ is

• A. All dwarf
• B. All tall
• C. 75% tall and 25% dwarf
• D. 75% dwarf and 25% tall

Answer 1

Answer: (B)

All tall

If a dwarf plant is treated with gibberellin it causes the increase in the height of plant. But that does not alter the genetic combination of the plant. The genotype still remains as tt.

Therefore, the cross will yield :
tt x TT ----> Tt (Tall plants)
All the plants obtained will be heterozygous tall.