MCB 150 Lecture Notes - Lecture 18: Intellectual Disability, Point Mutation, Fragile X Syndrome

• School: University of Illinois
• Department: Molecular and Cell Biology
• Course: MCB 150
• Professor: B Mehrtens

Document Summary

Process depend on reliable pairing of complementary bases: Dna replication more reliable the blueprint. Mistakes in replication lead to alterations in the nucleotide sequence in the dna. These alterations are passed onto daughter cells when the cell divides. Mutations heritable changes in the dna. In single-cell organisms all daughter cells have the mutation. In multi-cell organisms, mutations can be somatic or germ- Somatic (non sex cell) passed to daughter cells in area. Germ-line (sex cell) passed to new organisms. Rnas are not heritable over multiple generations. Important terminology: gene , gene+ laci+ is wild type (normal, unmutated) laci is mutated form of the gene. Frequency of mutations in e. coli about 0. 04 mutations/cell division. Average in all organisms 1 mistake in 1 billion nucleotides added efficient in vitro, e. coli dna polymerases make ~400 mistakes/cell division 10,000x the observed number!