Biology 1001A Lecture Notes - Lecture 8: Aneuploidy, Zygosity, Synaptonemal Complex

• School: Western University
• Department: Biology
• Course: Biology 1001A
• Professor: Tom Haffie

Document Summary

If there are repeats (i. e. aaaa) in dna, a base could slip a base pair could be lost or added. Highly repetitive sequences are susceptible to this problem. Polymerase can make a mistake if one of the strands slips during replication. This is an in/del (insertion/deletion) mutation (copy number variation) Radioactive atoms are simply unstable isotopes which decay. De(cid:272)a(cid:455) of radioa(cid:272)ti(cid:448)e iodi(cid:374)e a(cid:374)d (cid:272)esiu(cid:373) (cid:272)reates (cid:862)io(cid:374)izi(cid:374)g radiatio(cid:374)(cid:863) Radioactive iodine is dangerous because it is bioaccumulated in the thyroid. High e(cid:374)erg(cid:455) io(cid:374)izi(cid:374)g radiatio(cid:374), (cid:449)he(cid:374) it passes through (cid:455)our (cid:271)od(cid:455)"s (cid:272)ells, rips electrons from molecules, particularly oxygen. This creates reactive oxygen species (ros) which damage dna. Reactive oxygen can break dna backbones and if you break both backbones then the chromosome is broken. Repairing double stranded breaks can cause rearrangements like deletions, duplications, inversions, or translocations. Various types of chromosomal rearrangement resulting from attempts to repair double strand breaks. Deletions: an enzyme can remove a base pair from the sequence.