CRISPR answers

Question 1

what does CRISPR stand for

Answer 1

Clustered Regularly Interspaced Palindromic Repeats

Question 2

what system was CRISPR first recognized in

Answer 2

naturally occurring adaptive immune system first recognized in prokaryotes (40% of bacteria and 90% of archea)

Question 3

what are the two potential mechanisms CRISPR can undergo

Answer 3

1) Non-homologous end joining (NHEJ)
2) Homology-directed repair

Question 4

Non-homologous end joining repairs DNA

Answer 4

without a DNA template

Question 4

Homology-directed repair

Answer 4

uses a DNA template to guide the repair `

Question 5

describe the function of the PAM site

Answer 5

crucial for binding with cas proteins, and to help distinguish between self and non self DNA

Question 6

Six-step process of using CRISPR in experiments

Answer 6

1) Design the single guide RNA which directs Cas9 to the target DNA sequence
2) clone sg RNA into a vector (plasmid) which contains the Cas9 gene and an antibiotic resistance gene
3) amplified in E. coli
4) introduced to target cell with heat shock, electroporation or viral vectors
5) once inside Cas9 cuts the target DNA
6) DNA sequencing is used to confirm successful gene editing

Question 7

what is a possible side effect of target editing

Answer 7

development of imprinting disorders

Question 8

how was CRISPR used to genetically modify strawberries

Answer 8

promote the production of sweet genes , or increasing the sweetness of strawberries