Gene control by transcription factorsEdexcel A-Level Biology A: Mind map

Exam questions on Gene control by transcription factors

1. A researcher compares a liver cell and a skeletal muscle cell taken from the same person. Both cells contain exactly the same genome, but the two cells make very different sets of proteins.
   Explain how a transcription factor can switch on a gene.2 marks
2. Oestrogen is a steroid hormone that stimulates cells lining the uterus to make particular proteins. Oestrogen is lipid-soluble and acts by entering its target cells.
   Explain why oestrogen affects only certain cells in the body.2 marks
3. A scientist grows human cells in culture and measures the amount of mRNA made from gene X, in arbitrary units, after 6 hours. Cells with no oestrogen contained 4 units. Cells given oestrogen contained 52 units. Cells given oestrogen together with a drug that blocks the oestrogen receptor contained 5 units.
   Calculate the percentage increase in mRNA from gene X caused by oestrogen alone.3 marks