What happens to the recessive trait in the F2 generation after a cross of two F1 hybrids?

In a typical Mendelian inheritance scenario, when two F1 hybrids (heterozygous individuals) are crossed, the resulting F2 generation will display a phenotypic ratio that reveals the presence of the recessive trait.

The F1 generation, being the offspring of two true-breeding parents with contrasting traits, will show the dominant trait because it masks the effect of the recessive trait. However, during the formation of gametes in the F1 generation, the alleles segregate independently. When these gametes combine in the F2 generation, both dominant and recessive alleles are present.

The classic ratio observed in the F2 generation from such a cross is 3:1, where approximately 75% of the offspring display the dominant phenotype and 25% exhibit the recessive phenotype. This indicates that the recessive trait doesn't disappear or remain masked, but rather reappears as a phenotype in a quarter of the offspring. Thus, the recessive trait's presence in the F2 generation serves as a hallmark of Mendelian genetics, illustrating how traits segregate according to allele combinations.