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What is the difference between humoral and cell mediated immunity?

Humoral: An invading pathogen in the blood or lymph has foreign antigens on its surface. This activates B cells which then produce antibodies against the antigen.Cell mediated: One of the body’s own cells be...
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Answered by Charlotte A. Biology tutor
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How is blood glucose controlled in homeostasis?

Blood glucose increases and gets too high, this is detected by beta cells in the Islet of Langerhans. Increase in insulin secretion, this speeds up the rate of glucose uptake by tissue cells. Glucose gets tu...
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Answered by Mustafa A. Biology tutor
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How is a concentrated filtrate produced in the kidney to remove harmful toxins from the body?

To begin with, sodium ions are actively (using ATP) pumped out of the ascending limb of the loop of henle, however, as the ascending limb is impermeable, water remains . This creates a lower water potential ...
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Answered by Dan W. Biology tutor
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How may allopatric and sympatric speciation be distinguished? (4 marks)

First it is important to establish what a species is. A species is a population of similar organisms that can interbreed to produce fertile offspring; meaning they are reproductively isolated from other such...
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Answered by Gabrielle L. Biology tutor
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Describe the structure of the heart and its function in the human circulatory system.

The heart is a muscular organ composed of 4 chambers ; the left atrium and right atrium (pl. atria ) and the left ventricle and right ventricle (pl. ventricles ). The left and right sides of the heart are se...
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Answered by Aine O. Biology tutor
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