Question

In a field of sunflower plants, 776 plants are tall and 224 plants are short. Sunflower height follows the normal pattern of inheritance. Dominant traits masks recessive. Tall (T) is dominant and short (t) is recessive. What is the genotype of the short plants in the field?
A) T
B) TT
C) Tt
D) tt

Answer 1

Answer:

D) tt

Explanation:

Short plants must have two alleles for shortness. They are called homozygous recessive or tt.

Answer 2

Answer:

The correct answer would be D) tt.

Recessive traits need a homozygous condition to get expressed and to produce a particular phenotype. In contrast, dominant trait can be expressed  in homozygous as well as heterozygous condition of the alleles of a gene.

Now, shortness is a recessive trait encoded by allele "t". Hence, allele "t" must be present in the homozygous condition in order to make the plant short.

Thus, the genotype of all the short plants in the field should be tt and the genotype of the tall plants would be TT or Tt.