Question

In the cross Tt × Tt, according to the Punnett square, how many of the four possible offspring genotypes will express the tall phenotype?

Options

• All four equally express the tall phenotype

• Two (both TT and Tt)

• Three (TT, Tt, and tt)

• One (only TT)

Answer 1

In the Punnett square for Tt × Tt, the four possible genotypic outcomes are TT, Tt, Tt, and tt in a 1:2:1 ratio. The tall phenotype is expressed by both homozygous dominant (TT) and heterozygous (Tt) individuals because T is dominant. Therefore, three out of four offspring will be tall (1 TT + 2 Tt), and only one will be dwarf (tt), producing the 3:1 phenotypic ratio.