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How does an electrical impulse travel the gap between two nerves?

The electrical impulse that travels along a nerve, known in biology as an action potential, gets passed along to an adjacent nerve as a chemical signal. When an action potential reaches the end of a nerve, i...
LM
Answered by Lucy M. • Biology tutor
5266 Views

How does temperature affect enzymes?

Enzymes are proteins which catalyse (speed up without being used up) biological reactions. Each enzyme will only speed up one reaction as the shape of the enzyme molecule needs to match the shape of the mole...
LR
Answered by Liberty R. • Biology tutor
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Describe key structural differences between prokaryotic and eukaryotic cells.

Eukaryotic cells are larger and more complex than prokaryotic cells. The eukaryotic cell contains a nucleus, which contains genetic material in the form of linear chromosomes. However, prokaryotic cells cont...
TD
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Can lymphocytes have proteins that are complementary to host cell antigens?

You only kill off the ones that are reactive to host antigens (read: the ones that would attack your own cells!). So normal lymphocytic function isn't affected. Because of the nature of the immune system (yo...
SM
Answered by Scott M. • Biology tutor
3696 Views

A student cut a piece of potato into 10 discs, each 1mm thick and with a 10mm diameter. He then placed them in a beaker of deionised water. After a couple of days, they had increased in size- both thickness and diameter. Explain why this is the case.

The cells composing the potato tissue contain fluid, or cytoplasm. This contains dissolved salts and these ions attract water molecules; cations, or positive ions, attract the partially negatively charged ox...
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Answered by Eva K. • Biology tutor
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