replication of dna 1.2

Question 1

requirements for DNA replication

Answer 1

DNA template
Primers
Free DNA nucleotides
DNA polymarase
ATP

Question 2

stages of the LEADING strand

Answer 2

1. DNA is unwound, unzips as the hydrogen bonds break between the bases
2. primer binds to 3’ end of template strand
3. DNA polymerase goes along template strand adding new complementary nucleotides to template strand
4. DNA stands twist to form double helix

Question 3

stages of the LAGGING strand

Answer 3

1. DNA is unwound and unzips as the hydrogen bonds break between the bases
2. many primers bind at various points along the template strand
3. DNA polymarase stars to walk along the template strand, adding new complementary nucleotides to the template strand
4. fragments are joined together by enzyme ligase
5. DNA strands twist to form a double helix

Question 4

when does DNS replication occur

Answer 4

occur prior to cell division

Question 5

what is the role of DNA polymarase and primers

Answer 5

polymarase is the enzyme that replicates DNA
requires a primer to start DNA replication
primer is a short strand of nucleotides which bind to the 3’ end of the template strand

Question 6

What is Polymerase chain reaction (PCR)

Answer 6

technique used to create many copies of DNA
this occurs in the vitro as it occurs outside the body of the organism

Question 7

what is requires for PCR to work

Answer 7

• DNA template
• DNA polymerase
• Primers
  -DNA nucleotides

Question 8

How does PCR work

Answer 8

1. DNA mixture is heated to 92-98 degree, break hydrogen bonds between bases
2. temperature of mixture is reduced to 50-65 degrees, the primers can bind to target sequence
3. mixture is then heated to 72 degrees
4. the 1st cycle produces 2 identical molecules of DNA
5. 2nd cycles produces 4 identical molecules