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How do vaccinations work? Relating to humoral immunity and the secondary immune response.

The body has both humoral and cell mediated immunity. A vaccination involves injecting a patient with inert (Inactivated) or dead material from a pathogen, be that a bacterium or a virus. Once injected into ...
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Answered by Sophie J. Biology tutor
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Describe the transmission of a nerve impulse across a synapse.

An action potential arrives at a presynaptic neurone, which causes calcium ion channels to open. Calcium ions enter the presynaptic knob, which causes synaptic vesicles containing neurotransmitter to detach ...
Answered by Biology tutor
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How does speciation occur?

A barrier separates the original population into two groups. Due to the different environmental conditions (selection pressures) either side of the barrier, different alleles are selected that better adapt t...
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Answered by Hasna B. Biology tutor
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Describe the process of the light-independent reaction.

Carbon dioxide diffuses into the cell leaf through the stomata, and diffuses into the water surrounding the mesophyll cell walls (main site of photosynthesis-packed with many chloroplasts). From here, the ca...
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Answered by Davinia I. Biology tutor
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What is homeostasis and give 3 examples of homeostasis in the body.

Homeostasis is the maintaining of a constant internal environment to allow for healthy functioning of the body. Three examples would be the control of water levels in the kidney via ADH, control of temperatu...
Answered by Biology tutor
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