Question

In a monohybrid cross, when an F${}_1$ plant is crossed with a homozygous dominant parent, the offspring will be:

• A. Dominant : recessive in the ratio 3:1
• B. Only recessive plants
• C. Dominant : recessive in the ratio 1:1
• D. No recessive plants

Answer 1

The correct option is D No recessive plants

The genotype of a tall plant in the $F_1$ generation of a monohybrid cross is $Tt$. When it is crossed with a dominant parent with genotype $TT$, the crossing can be shown as described in the given Punnett square.

The crossing produces offspring with genotypes $TT$ (Homozygous dominant) and $Tt$ (Heterozygous dominant). Hence all offspring will contain the dominant allele and hence there won't be recessive offspring.

So, the correct answer is option D.