AMCB 6 Exam Questions with Correct Answers

AMCB 6 Exam Questions with Correct Answer s Xeroderma pigmentosum (XP) - Answer -Rare autosomal recessive disease Extreme sensitivity to UV light People with XP have defective nucleotide excision repair pathways Cockayne Syndrome - Answer --Another DNA repair deficiency like XP -Characterized by photosensitivity, premature aging, neurological symptoms, and early death -Defect in transcription -coupled repair -Said to arise from RNA pol molecules permanently stalled at sites of DNA damage that lie in important genes Mutations become apparent - Answer -only after cell division; yielding 1 WT and 1 mutant cell Point mutation - Answer -(missense, nonsense, silent): change of base pair caused by: rep mistake, chemically alt base that mispairs Deletion mutation - Answer -removal of one or more base pairs in the DNA caused by: intercalating chemicals, DNA Pol slips, mobile genetic elements Insertion mutation - Answer -insertion of one or more bases caused by: intercalating chemicals, mobile genetic elements Frameshift mutation - Answer -deletion or insertion of a number of bases that cannot by divided by 3 caused by: intercalating chemicals, mobile genetic elements Inversion mutation - Answer -inversion of a sequence of bases (may cause frame shift) caused by: mobile genetic elements transition point mutation - Answer -purine to purine or pyrimidine to pyrimidine transversion point mutation - Answer -purine to pyrimidine pyrimidine to purine spontaneous mutation - Answer -"tautomeric shift" - spontaneous, transient rearrangement to an alternative form