Question

A cross between two tall plants resulted in offspring of which ¼ were dwarf plants. What would be the genotypes of both the parents?

• A. TT and tt
• B. TT and Tt
• C. TT and TT
• D. Tt and Tt

Answer 1

The correct option is D Tt and Tt

If a cross between two tall plants results in a ¼ dwarf offspring, then both of the tall plants must be heterozygous i.e. Tt.
$\begin{array}{ccc}& \text{T}& \text{t}\\ \text{T}& \text{TT(Tall)}& \text{Tt(tall)}\\ \text{t}& \text{Tt(tall)}& \text{tt(dwarf)}\end{array}$
In all the other options given above, all the offspring would be tall plants only.