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How is a nervous impulse transmitted across a synapse?

An action potential (AP) reaches the pre-synaptic membrane. This causes the voltage-gated calcium channels to open, and calcium ions flow down their concentration gradient into the pre-synaptic terminal. Thi...
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Answered by Teodora N. • Biology tutor
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Describe prions and their function, give example of prion disease

Prions are certain proteins naturally occuring in organisms that have assumed wrong conformation during folding. This misfolded structure is highly infectious - if it comes into contact with healthy version ...
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Answered by Klára N. • Biology tutor
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Explain the role of auxins in the control of phototropism

A phototropism is the growth of a plant in response to light. This is mediated by auxins such as IAA (Indoleacetic acid). This is released in the tips and shoots of flowering plants. In response to light IAA...
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Answered by Florence T. • Biology tutor
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Explain the route and role of calcium ions in the Sliding Filament theory of muscle contraction

ROUTE: when an action potential arrives at the neuromuscular junction , Calcium ions are released from the sarcoplasmic reticulum, into the sarcoplasm, where they bind to the troponin molecules on the tropom...
EC
Answered by Erin C. • Biology tutor
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Explain How Macrophage becomes an Antigen presenting cell

Phagocytosis occurs:The Macrophage surrounds and envelops the pathogen with pseudopodia The pseudopodia envelops the bacteria completely forming a vesicle, called a phagosomephagosome is fused with a lysosom...
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Answered by Ibtihaj C. • Biology tutor
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