The giant growth of oats is a recessive sign. What can be said about the genotypes of a parental couple if half

The giant growth of oats is a recessive sign. What can be said about the genotypes of a parental couple if half of the offspring are of normal growth and half of them are giant? what if only a quarter of the offspring is gigant?

Let’s designate the gene that causes giant growth in oats as k, then the gene that causes normal growth of this plant will be K.

The splitting of the offspring according to the phenotype, corresponding to a ratio of 1: 1, characterizes the so-called analyzing crossing, in which a heterozygote is crossed with a homozygote for a recessive gene.

Heterozygous Kk oats will grow normally and produce two types of gametes, k and K.

Homozygous for giant growth oats kk will have giant growth and produce germ cells of the same type – k.

The offspring will be formed by the following options:

heterozygous oats with normal growth (Kk) – 50%;

homozygous oats with giant growth (kk) – 50%.

Splitting in a proportional ratio of 3: 1 is characteristic of crossing two heterozygotes. Oats with the Kk genotype will grow normally.

The offspring from crossing heterozygotes with each other includes the following possible options:

homozygous oats with normal growth (KK) – 25%;

heterozygous oats with normal growth (2Kk) – 50%;

homozygous oats with giant growth (kk) – 25%.