2.3 How variable are individual genomes? Haplotype is the particular combination of alleles in a defined region of some chromosome. in effect the genotype in miniature. Originally used to described combinations of MHC alleles. it now may be used to describe particular combinations of RFLPS SNP (sIngle nucleotide polymorphism) Is any site at which a single nucleotide has changed when two (haploid) genomes are compared 消当Haplotype is the particular combination of alleles in a defined region of some chromosome, in effect the genotype in miniature. Originally used to described combinations of MHC alleles, it now may be used to describe particular combinations of RFLPs. SNP (single nucleotide polymorphism) is any site at which a single nucleotide has changed when two (haploid) genomes are compared. 2.3 How variable are individual genomes?