In the second generation, an individual must have two copies of a recessive allele to express the trait if a trait is recessive.
Explanation:
Mendel stated the visible form as dominant trait and hidden form as recessive trait. During second generation the plants are allowed to fertilize the hidden form of the trait that appeared in most of the plants.
Only the individuals with an genotype will represent a recessive trait and hence the offspring should receive one recessive allele from each parent to exhibit a recessive trait.
If the two copies of the gene in an organism are identical and have same allele is called homozygous. If an organism has two different alleles of the gene is called heterozygous.
