Answer :
The F1 generation differed from the F2 in the Mendel's experiments in that all the F1 generation showed the dominant phenotype, however only three- fourths or three quarters of the F2 generation did. This is because all the F1 generation were heterozygous and thus the dominant phenotype was expressed, while in the F2 generation there was a mixture of homozygous dominant, homozygous recessive and heterozygous. Therefore, the heterozygotes and the homozygotes dominant showed a dominant phenotype.