A particular garden pea plant produces plants that have only violet flowers.

(a) Is it homozygous or heterozygous dominant for the trait?

(b) How would you ensure its genotype? Explain with the help of crosses. [5]

(a) As the plant produces plants which have only purple flowers, it is homozygous dominant (PP). Purple flower is the dominant trait. [1]

(b) Its genotype can be ensured by performing a test cross in which the pea plants (showing a dominant phenotype i.e purple flowers) is crossed with the recessive parent (showing recessive phenotype i.e white flowers). [1]

If this cross, produces all violet flowers, then the parent plant is homozygous dominant. [1.5]


If the cross produces white and purple flowers, the parent plant is heterozygous dominant. [1.5]