What will be the genotypic ratio when two heterozygous red pea plants are crossed?

When two heterozygous red pea plants are crossed, the genotypic ratio of the offspring will be 1:2:1. This means that out of four offspring, one will have a homozygous dominant genotype (RR), two will have heterozygous genotypes (Rr), and one will have a homozygous recessive genotype (rr). To understand why this is the case, we need to know about the principles of Mendelian genetics. In pea plants, the gene that controls the color of the seed coat has two possible alleles: R (which produces red color) and r (which produces white color). When two heterozygous pea plants (Rr) are crossed, each parent contributes one allele to their offspring, resulting in four possible combinations: RR, Rr, rR, and rr. Out of these four combinations, only one will result in a homozygous dominant genotype (RR), two will result in a heterozygous genotype (Rr), and one will result in a homozygous recessive genotype (rr). Therefore, the genotypic ratio of the offspring will be 1:2:1.