Transcription 7.2 HL

This topic includes some of the more difficult details about the process of transcription of mRNA from DNA. The way that splicing of mRNA to remove introns can also make different mature mRNA molecules leads to an increase in the number of proteins which can be made by a gene. Other factors affecting gene expression are also considered, e.g. methylation and the role of proteins.


Key words

Learn and test your biological vocabulary using these 7.2 Transcription flashcards 

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 gene expression

Explaining the control of gene expression, methylation and promotor regions is an important skill from this topic.

Answer the question below on a piece of paper, then check your answer against the model answer below.

Explain how nucleosomes, promotors and methylation can control of gene expression in eukaryotes. [4]

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Revision summary list for topic 7.2 Transcription

  • The direction of Transcription is in a 5’ to 3’ direction as RNA polymerase adds the 5´ end (phosphate) of the free RNA nucleotide to the 3´ end of the growing mRNA molecule.
  • Transcription is partly regulated by Nucleosomes in eukaryotes.
  • Eukaryotes modify mRNA after transcription.
  • Splicing of mRNA increases the number of different proteins an organism can produce.
  • Gene expression is regulated by proteins that bind to specific base sequences in DNA. - eg. methylation
  • Gene expression is affected by the environment of a cell and of an organism.

Skills

  • Awareness that the promoter region is an example of non-coding DNA.
  • The skill to analyse changes in the DNA methylation patterns in connection with gene expression

Revision mindmaps

These diagram summaries cover the main details of topic 3.5 Genetic modification.
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Review questions

This quiz contains multiple choice questions covering the understandings and skills in this topic.


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Revision fun activity

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