BIOLOGY 2C03 Lecture Notes - Lecture 3: Phenylalanine, Thalidomide, Phocomelia
Document Summary
Individual (diploid) only two alleles coexist in each cell. Eg/ multiple alleles contributing to fur coloration in cats. C = full color cb = burmese cs = siamese c = white, blue eyes ca = albino, pink eyes: c > cb = cs > c > ca, where: The relationship between pairs of alleles is important. When determining phenotype, look at the dominance relationship between the two alleles in a single individual. The c gene codes for an enzyme called tyrosinase. Comparison of wildtype and albino allele: a cytosine deletion in tyrosinase at position 975 in exon 2, which causes a frameshift resulting in a premature stop codon nine residues downstream from the mutation. The number of different genotypes is determined by the number of alleles in the population: c, ca, cs, cb c (wildtype, this gives, 15 genotypes of which there are five different homozygous genotypes and 10 different heterozygotes.
