BI226 Chapter Notes - Chapter 4: Antirrhinum, Lethal Allele, Phenol
Document Summary
Alleles alternative forms of the same gene: wild type most frequently/consider normal (doesn"t always have to be dominant, mutant type a mutation in a gene may ultimately change the conformation of the enzyme and reduce or eliminate its affinity for the substrate. The abo blood group is characterized by antigens on the surface of the red blood cell: a antigen = a type, b antigen = b type, a + b antigens = ab type, no antigens = o type. Ex: the homozygous presence of a recessive allele prevents or overrides the expression of other alleles at a second locus: alleles at first locus are epistatic to those at the second locus, alleles at the second locus are hypostatic to those at the first locus, ex: dominant allele at first locus overrides whatever is at the second locus, ex: bombay phenotype.
