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Biology

A Level

How should I revise?

First of all it is important to have clear and useful notes to revise from.

Keep your school notes organised and you can write your own notes while looking back over these online sessions...

Answered by Sarah B. • Biology tutor

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What is negative feedback and what is positive feedback? Give an example for each of where it is important in regulation?

Negative feedback: occurs where the feedback causes the corrective measures to be "switched off", and in doing so returns the system to its original level.

Exam...

Answered by Sarah B. • Biology tutor

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(Briefly) describe the four phases of aerobic respiration?

Glycolysis: Takes place in the cytoplasm and involves the oxidation of a 6-carbon glucose molecule to two 3-carbon pyruvate molecules with a net gain of ATP and reduced NAD (2 molecule...

Answered by Sarah B. • Biology tutor

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What is the difference between Mitosis and Meiosis?

Both meiosis and mitosis are types of nuclear division. The main difference between the two is the number of nuclear divisions that take place:

Answered by Sarah B. • Biology tutor

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What is the function of mitochondria?

Mitochondria are the 'powerhouses' of the eukaryotic cell. These organelles are the sites of cellular respiration, the metabolic process that generates energy from carbohydrates in the cell. The energy...

Answered by Sarah B. • Biology tutor

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