Describe the process of eukaryotic DNA replication

DNA helicase unzips and unwinds the DNA double helix by breaking hydrogen bonds between complementary base pairs. This exposes the bases on two strands creating template strands. Free floating nucleotides are attracted to the exposed bases and bond to them via complementary base pairing (adenine-thymine and guanine-cytosine). DNA polymerase then joins the new nucleotides together in a series of condensation reactions forming phosphodiester bonds in the sugar-phosphate bakcbone.Two new DNA strands are made, each with one old strand and one new one therefore DNA is said to be replicated semi-conservatively.

LB

Related Biology A Level answers

All answers ▸

How can I remember all of the content in A-Level biology?


Tetrodotoxin (TTX) is a chemical found in pufferfish which binds to voltage-gated sodium channels causing inactivation via a conformational change. Poisoning can result in paralysis leading to death. How might this occur? (4 marks)


Describe how negative feedback is used to control blood glucose concentration (6 marks)


How does the wave of conduction pass through the heart?