Practise IB Biology HL 1.1.1 by explaining DNA replication at molecular level and evaluating the evidence for accurate copying.
Angiospermophyta are vascular flowering plants.
Growth in living organisms includes replication of DNA. Explain DNA replication.
a. helicase unwinds the double helix
b. gyrase/topoisomerase relieves strains during uncoiling
c. helicase separates the two strands of DNA/breaks hydrogen bonds
d. each single strand acts as a template for a new strand / process is semi-conservative
e. DNA polymerase III can only add nucleotides to the end of an existing chain/to a primer
f. (DNA) primase adds RNA primer/short length of RNA nucleotides
g. DNA polymerase (III) adds nucleotides in a 5′ to 3 ' direction
h. complementary base pairing / adenine to thymine and cytosine to guanine
i. DNA polymerase (III) moves towards the replication fork on one strand and away from it on the other strand
j. continuous on the leading strand and discontinuous/fragments formed on the lagging strand
k. DNA polymerase I replaces primers/RNA with DNA
I. ligase joins the fragments together/seals the nicks
Marking guidance:
Accept unzips here but not for mark point a.
Do not accept letters.
8 max