In Drosophila, the red eye character is dominant over white eye character. When a homozygous red-eyed individual is crossed with a homozygous white-eyed individual, and individuals of F1 generation are intercrossed, 12 individuals are produced. White-eyed individuals of these will be:
It is a monohybrid cross. Monohybrid cross produces progeny of F2 generation in ratio 3:1 where 1 is the ratio of recessive progeny. Here in, the number of recessive white-eyed individuals can be found by:
Total number according to ratio = 3+1 = 4.
Total number of individuals produced actually = 12
Number of white-eyed individuals = 14×12=3