DNA Replication, transcription, translation 2.7

The discovery of the structure of DNA immediately suggested a method of copying the genetic material to Watson and Crick in 1953. This topic looks at these methods, DNA replication making an exact copy of the genetic material as well as Transcription and translation in the expression of a gene to make a protein.


Key words

Learn and test your biological vocabulary for 2.7 DNA replication using these flash cards 

Clean sweep - quick revision through the whole topic

These slides summarise the essential understanding and skills in this topic. 
They contain short explanations in text and images - good revision for all students.

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Structured question about an application of DNA replication

Answer the question below, which addresses one application of DNA replication.
(Thanks to Catarina Gouveia and her students for the question and markscheme)

Outline the role of Taq DNA polymerase in the polymerase chain reaction (PCR) [4]

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Revision summary list for topic 2.7 DNA Replication

  • DNA replication
  • Complementary base pairing leads to the semi-conservative replication of DNA.
  • The enzyme helicase unwinds the double helix and breaks hydrogen bonds which hold the two DNA strands together.
  • DNA polymerase (generalised name) links DNA nucleotides together to form a new strand DNA,using the pre-existing strand as a template.
  • Transcription is the synthesis of mRNA by RNA polymerase using the DNA base sequence as a template
  • Translation is the synthesis of polypeptides on ribosomes.
  • The amino acid sequence of polypeptides is determined by mRNA according to the genetic code.
  • Three bases of mRNA is called a codon and corresponds to one amino acid in the polypeptide.
  • Translation depends on complementary base pairing between codons on mRNA and anticodons on tRNA.
  • Awareness that in polymerase chain reaction (PCR) an enzymes called Taq DNA polymerase produces multiple copies of DNA.

Revision mind map

This diagram summaries the main sections of topic 2.7.
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Review questions

This is a self marking quiz containing questions covering the topic outlined above.
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Revision fun activity

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If you can't see the content below, please click: DNA replication,  transcription and translation card matching game