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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 process of DNA replication

In DNA replication, first the hydrogen bonds between the nitrogenous bases are broken catalysed by the enzyme helicase, causing the DNA double helix to unwind and unzip, leaving the nitrogenous bases exposed...
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Answered by Helena N. • Biology tutor
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