HMB265H1 Chapter Notes - Chapter 15&16: Dna Mismatch Repair, Rhodopsin, Tautomer

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Naomi Levy-Strumpf, Stephen Wright

Document Summary

Rhodopsin, a light-sensitive protein found in rod cells and found on chromosome 3. A mutation in the rhodopsin gene is enough to lead to night blindness. Other alterations can completely destroy rod cells, leading to blindness. Mutations modify the structure or amount of a gene"s protein product; these modifications influence phenotype. All other mutations either alter genes in a way that doesn"t affect function or change the dna between genes. Mutation rates are very slow; very few mutations actually affect gene function. The rate of forward mutation is higher than the rate of reverse mutation (there are more ways to disrupt gene function than restore it) Mutation rates in multicellular organisms are higher than in bacteria. Diploid genome tolerates mutations better than bacteria. Many cell divisions between the zygote and meiosis, allowing for mutations to accumulate. There are more mutations in sperm than in eggs. Sperm undergo many more mitotic divisions, leading to higher chances of mutation.