Top answers


What are the best strategies/ ways of helping me revise?

- Running through past exam papers - Reading, memorising, and re-writing - Taking regular breaks
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Answered by Georgina H. Biology tutor
4013 Views

Explain how smoking can increase blood pressure?

There are two main reasons that smoking can increase blood pressure: Cigarette smoke contains nicotine which, once inhaled, can enter the bloodstream and cause the release of adrenaline which increases the h...
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Answered by Oliver H. Biology tutor
8109 Views

How do fish carry out gas exchange efficiently?

Fish use specialised surfaces called gills to carry out gas exchange. Gills are highly folded, giving them a large surface area and maximising the efficiency of gas exchange. The gill filaments have many pro...
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Answered by Shoam B. Biology tutor
129705 Views

How does speciation occur?

Reproductive separation occurs, this could be through geographical separation . (1) Therefore no interbreeding in the population. (2) This results in separate gene pools . (3) Variation due to random mutatio...
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Answered by Shoam B. Biology tutor
6530 Views

How does a neuron maintain its resting potential and why is it important?

The membrane of an axon contains a large number of protein channels along its length, which all fall under three categories: the sodium/potassium pumps, the voltage-gated sodium channels & the voltage-ga...
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Answered by Ferdinand B. Biology tutor
27737 Views