A-Level Biology AQA 7402

In eukaryotes, transcription of target genes can be stimulated or inhibited when specific transcriptional factors move from the cytoplasm into the nucleus. The role of the steroid hormone, oestrogen, in initiating transcription.

Epigenetic control of gene expression in eukaryotes.

Epigenetics involves heritable changes in gene function, without changes to the base sequence of DNA. These changes are caused by changes in the environment that inhibit transcription by:

• increased methylation of the DNA or
• decreased acetylation of associated histones.

The relevance of epigenetics on the development and treatment of disease, especially cancer.

In eukaryotes and some prokaryotes, translation of the mRNA produced from target genes can be inhibited by RNA interference (RNAi).

Students should be able to:

• interpret data provided from investigations into gene expression
• evaluate appropriate data for the relative influences of genetic and environmental factors on phenotype.