A tall plant crossed with a dwarf one produces offspring of which half are tall and half are dwarf. What are the genotypes of the parents?

Answer Details

This pattern of inheritance can be explained by the laws of segregation and independent assortment proposed by Gregor Mendel. According to these laws, every individual has two copies of each gene, one inherited from each parent, and these copies can be either dominant or recessive. In this case, we are told that a tall plant (let's call it T) was crossed with a dwarf one (let's call it t) and produced offspring that were half tall and half dwarf. This means that the tall parent must have had two dominant alleles (TT), while the dwarf parent must have had two recessive alleles (tt). When the two parents were crossed, their offspring inherited one allele from each parent. Since the tall parent had two dominant alleles, it could only contribute a T allele to its offspring, while the dwarf parent could only contribute a t allele. This means that all the offspring were heterozygous (Tt), meaning they had one dominant allele and one recessive allele. Half of the offspring were tall, meaning they inherited a dominant T allele from the tall parent. The other half were dwarf, meaning they inherited a recessive t allele from the dwarf parent. Therefore, the genotypes of the parents are Tt and tt.