It is the recessive trait that is visible in the F2 generation, but not the F1 generation of the Mendel Crosses.
In a recessive trait, the organism has two recessive allele or similar form of gene.
In the F1 generation all the off springs are heterogeneous with different allele but in the F2 generation the recessive allele comes from the alleles passed on by the parents (off springs of the F1 generation , which have recessive allele)
