Question

When a tall plant with round seeds (TTRR) crossed with a dwarf plant with wrinkle seeds (ttrr), the F${}_1$ generation consists of tall plants with round seeds. What would be the proportion of dwarf plant with wrinkle seeds in F${}_1$ generation?

• A. 1/4
• B. 1/16
• C. 0
• D. 1/2

Answer 1

The correct option is C 0

Here in this case, tall and round are the dominant characters that are strong enough to express even when heterozygous in nature.
Tall plant with round seeds: TTRR
Gametes produced: TR
Short plant with wrinkled seeds: ttrr
Gametes produced: tr
Crossing of the gametes will yield the F${}_1$ generation.
TR x tr $\to$ TtRr (F${}_1$ generation)
Here, the dominant character tall and round are represented by T and R respectively and thus, it expresses round seeds and tall phenotype.
Hence, the number of short plants in F${}_1$ generation is zero.

Thus, the correct answer is option C.