2.2 DNA replication

Question 1

What are the two stages of cell division?

Answer 1

1. nuclear division - the nuclear divides (eg. mitosis, meiosis)
2. cytokinesis - the whole cell divides

Question 2

What must be done before the nucleus divides?

Answer 2

DNA replication

Question 3

What is the model called that shows how DNA replicates?

Answer 3

Semi-conservative model

Question 4

What are the stages of semi-conservative replication?

Answer 4

1. DNA helicase (enzyme) breaks the hydrogen bonds that link the bases together
2. the double helix separates into two strands
3. each exposed polynucleotide strand acts as a template as free nucleotides attract to their complementary bases
4. DNA polymerase (enzyme) join the free nucleotides together in condensation reaction
5. each copy of DNA is made up of one original DNA strand and one new DNA strand