Considering the relationship in the first pair, complete the second pair : rr: Homozygous :: Rr : Heterozygous. When two alleles of same gene are found in an individual then the individual is said to be homozygous. These may be either recessive (rr) or dominant (RR). In contrast, when two alleles of different gene are found in an individual then the individual is said to be heterozygous (Rr).