Biology 1001A Lecture Notes - Lecture 8: Metaphase, Base Pair, Dna Replication
3 Apr 2016
School
Department
Course
Professor
Document Summary
Snps of africans have more variation than other ethnicities. Genetic variation arises out of inherit chemical instability of biochemistry of dna: cannot be prevented, snps cannot be prevented, mutations arise spontaneously. Snps: substitution mutations: gc pair where there used to be an at pair. Occurs when repeats of bases: ex. repeats of at pairs. Its okay if the new strand (t) loops because a still pair with t. T"s are still stable even though one looped out. There is an insertion (an extra t) New strand loops new strand is too long and has an insertion: same thing can happen in template loop template: deletion. Slipage during replication can give rise to in/dels. Regions of repeated sequence are susceptible to in/del mutations. Mutations are undirected (no specific reason: don"t solve a particular problem. Each base/region in genome is not equally likely to suffer a mutation/or be changed. Regions that are highly repeated are hot spots for slippage (in/del mutations)
