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Biology
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Putting bee honey on a cut kills bacteria. Honey contains a high concentration of sugar. Use your knowledge of water potential to suggest how putting honey on a cut kills bacteria.

Sugar is a solute, so honey contains a high concentration of solutes. This increases the solute potential, and decreases the water potential of honey, which is therefore lower than the water potential in ...

Answered by Nighat K. Biology tutor
2686 Views

Give three features of an efficient exchange surface. Provide an example for each feature.

An efficient exchange surface should have a high surface area as this increases the rate at which diffusion can occur across it. For instance, roots have many root hair cells. These root hair cells have t...

Answered by Elliot H. Biology tutor
10936 Views

How is a nerve impulse transmitted across a synapse?

Synapses are a gap or a junction between two neurones. When a nerve impulse is travelling along the axon of the first neurone and the impulse reaches the axon terminal (the end of the axon), a chemical ca...

Answered by Smita K. Biology tutor
3437 Views

Explain the differences between diffusion, osmosis and active transport.

Diffusion is the movement of particles (gases and liquids) from an area of high concentration to an area of low concentration. No energy is required (it is a passive process).Osmosis is the movement of wa...

Answered by Rikesh M. Biology tutor
3991 Views

How is heart rate controlled?

The heart muscle is myogenic, meaning that it is able to initiate its own contraction. The wall of the right atria has a region of specialised fibres known as the sinoatrial node ...

Answered by Beth M. Biology tutor
4553 Views

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