MBIO 2020 Lecture Notes - Lecture 18: Nucleoside Triphosphate, Transversion, Base Pair
10 Nov 2016
School
Department
Course
Professor
Document Summary
Bacteria - good for studying mutations - simple genetic systems: chromosome - 1 molecule of circular dna - 3,500 kbp, haploid - 1 set of genes. Cell division is always slower than chromosome replication: much more complex and energy demanding. Replication maintains constant base sequence - genome stays the same. Mutation - alteration in nucleotide sequence in genes: alter genotype - phenotype. Mutations are important because: they are heritable, provide material for evolution. 1 cell in about 108-1011 will have a mutation in any gene: hz - 10-8 - 10-11. 1 cell in 105-108 will have a mutation somewhere in its chromosome: hz - 10-5-10-8. Macrolesions - alterations of large segments of dna: large insertions and deletions, duplications - segment is repeated at a different site. Paralogues - duplicated gene forms a new function. Inversions - segment is reversed: translocation - moved to a different location.
