Biology 1001A Lecture Notes - Lecture 8: Ionizing Radiation, Caesium, Indel
Document Summary
African populations more variable in snps than other ethnic groups. Some mutagens are tautomerically unstable base analogues . Genetic variation spontaneously arises from the inherent instability of the biochemistry of dna: dna replication itself is mutagenic. It cannot be prevented, snps cannot be prevented. Some chemical mutagens increase rate of mutation, but mutations would still exist. Snp: g-c pair where there there used to be a-t. String of ts relatively stable because rest of pairing is fine. Template strand can also loop out, resulting in deletion. It is undirected but each base in genome is not equally likely to mutate. Each region of genome is not equally likely to mutate. Hot spots: regions that are highly repeated are more susceptible to in/del mutations. Ionizing radiation creates ros that damages dna: ex. Repairing double-strand breaks can create rearrangements: deletion, duplication, inversion, translocation chunk of one chromo attached to another, chromosomal level mutation happen as result of repairing breaks, ex.
