What is the phenotype ratio in hybrids obtained from crossing heterozygous and homozygous plants?

Let’s designate the gene that determines the development of the dominant trait as G, and the gene for the recessive trait as g.

The heterozygous plant will have the Gg genotype. It will produce two types of germ cells – G-containing and g-containing.

A homozygous plant can be either dominant or recessive. Let’s consider both options.

Let the plant be homozygous for the recessive gene – gg. It produces germ cells of the same type – g. The offspring from crossing with a heterozygote Gg will look like: heterozygote with a dominant phenotype (Gg) – 50%; homozygotes with a recessive phenotype (gg) – 50%. Phenotypic cleavage is 1: 1;

Let the plant be homozygous for the dominant gene – GG. It produces the same type of germ cells – G. Offspring from crossing with a heterozygote Gg includes options: homozygotes with a dominant phenotype (GG) – 50%, heterozygotes with a dominant phenotype (Gg) – 50%. Phenotypic cleavage will not be observed.

Answer: if the second plant is homozygous for the recessive gene – 1: 1.