CMMB 403 final exam Question and answers already passed

CMMB 403 final exam Question and answers already passed CMMB 403 final exam what does CRISPR use in order to generate changes in genome? is CRISPR forward or reverse genetics? - correct answer - nuclease - 20 nucleotide RNA sequence to target specific sites in the genome - reverse genetics what is the role of Cas9 in CRISPR - correct answer endonuclease that catalyzes double stranded breaks what are the two repair paths cells can use to repair double stranded breaks from CRISPR-Cas9 - correct answer 1. non-homologous end joining (NHEJ) - naturally try to repair - imperfect, creates indels causing frameshift mutation 2. directed homology repair - sequence homology on 5' and 3' ends to encourage homologous recombination flanking the double stranded breaks - insert known sequences to try and treat genetic diseases explain the method of conditional gene inactivation - correct answer - make targetting construct in lab - electroporate construct into embryonic stem cells to target endogenous Shox2 locus - mice generated by blastocyst injection into ESCs carry loxP sites therefore can delete Shox2 2 components for a conditional knockout mouse - correct answer 1. transgenic mice express Cre recombinase in the tissue of interest 2. mice with loxP sites on each side of the gene or region to be deleted How is CRISPR-Cas9 being used in a patient in the USA to treat sickle cell anemia? - correct answer by inactivating an enhancer o