BIO207H5 Lecture Notes - Lecture 14: Phenotype, Phenylalanine, Valine
Document Summary
Sidestep natural selection with delayed age of onset. The symptoms don"t show up until they are old (in their 40s or 50s) Affect multiple and apparently unrelated phenotypes: epistasis, suppression of the gene by another. But it is expressed in just one sex. Due to differential influence of sex hormones. Both males and females have the genes to product. But in females the gene is expressed resulting in hormone product. Horn development in males of some species. B1b2 (females beardless, males bearded) This shows that the genotype does not determine a. Affected individuals usually have more than five fingers and toes. But the individuals that carry this dominant allele could not manifest this. Nonpenetrant in about 25-30% of individuals carrying it. Same genotype but phenotype displayed to a varying degree of severity. Varying degrees of deafness, defects in structures, pigmentation anomalies etc. , In the incomplete penetrance either the individual shows the defect or they do not.
