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Describe how the lac operon works when lactose is both present and absent.

When lactose is absent the lac operon is switched off. This is becasue a repressor protein is produced which binds to the operator region. This prevetns RNA polymerase from binding to the operon and therefor...
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Answered by Suzannah E. • Biology tutor
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Describe the stages in DNA transcription and translation

First DNA helicase unwinds the strand of DNA. Then, DNA polymerase binds to the anti-sense strand of the DNA and adds RNA nucleotides in a sequence complementary to the strand of DNA. The DNA polymerase cata...
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Answered by Iona N. • Biology tutor
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How does Acetylcholine act on a neuronal synapse, and how is it re-uptaken?

- Ca2+ voltage gated channels are activated due to an action potential reaching the synapse - Acetylcholine rests in the pre-synaptic cleft - They are stored in vesicles - The calcium influx causes the vesic...
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Answered by Krishan R. • Biology tutor
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How does the potential travel between synapses?

The potential or information travels between a pre-synaptic and a post-synaptic neuron. As a reminder, for information, we intend the flow of Na+ and K+ ions between two locations. When the potential arrives...
FA
Answered by Filippo A. • Biology tutor
2927 Views

Outline the process of mitosis

Meiosis is the process of cell division that produces two identical diploid cells, and consists of four stages. The first stage is called prophase, where the chromosomes condense and cross over to form bival...
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Answered by Anastasia R. • Biology tutor
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