Outline the process of DNA replication.

For organisms to grow and repair cells are constantly replicating, and therefore the DNA within cells is also constantly replicating. The process begins with the enzyme DNA helicase breaking the hydrogen bonds between the nitrogenous bases, causing the two DNA strands to separate. Following this, complementary DNA nucleotides will pair up with the bases on each template strand, facilitated by the enzyme DNA polymerase. Finally, the enzyme DNA ligase joins the adjacent nucleotides together by catalysing the formation of phophodiester bonds. This kind of replication is described as semi-conservative, since each new DNA molecule contains one strand from the original DNA and one new strand.

LH

Related Biology A Level answers

All answers ▸

In mutations, what are the possible ways in which the DNA can be modified to make the proteins from which it is produced, non-functional or inactivated?


Identify the differences between motor and sensory neurons in terms of features and function.


Describe how mutations in tumour suppressor genes can lead to the development of tumours


Compare the differences between the sympathetic and the parasympathetic nervous system.