UNIT 1.2 Flashcards
1
Q
dna rep happens before mitosis in the
A
interphase
2
Q
dna polymerase is needed to
A
add dna nucleotides
3
Q
primers as
A
short chains of nucleotides that bind to the 3’ end of the template
4
Q
the 2 enzymes involve in dna rep
A
- dna polymerase
- ligase
5
Q
dna polymerase adds nucleotides in
A
only one direction
3’ to 5’
6
Q
difference between leading and lagging strand
A
- leading synthesised continuously
- lagging synthesised discontinuously, in fragments joined together by ligase
7
Q
stages of dna rep
A
- weak hydrogen bonds between bases break
- this unravels the dna’s double stranded helix structure, forming 2 template strands
- primers attach to the 3’ ends of the template strands
- dna p moves along strands adding new complimentary nucleotides to the 3’ of the new strands
- leading is replicated continuously
- lagging is replicated discontinuously, in fragments
- fragments of DNA are joined by ligase
8
Q
stages of PCR - in brief
A
heating 92-98
weak hydrogen bonds break and form two template stands
annealing 50-65
allows primers to bind to target sequence
extension 70-80
for heat tolerant dna polymerase to replicate the region of dna
9
Q
practical applications of PCR
A
- paternity tests
- solving crimes
- diagnosing genetic disorders
