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(a) (i) Give a biological molecule that contains: 1. nitrogen 2. phosphorous (ii) Describe the role of microorganisms in producing nitrates from the remains of dead organims.

(i) 1. amino acid 2. DNA(ii) Decomposer microrganisms break down dead material into ammonia. Ammonia is then converted into nitrite and then oxidised to nitrate by nitrifying bacteria. The process is known a...
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Answered by Alice S. • Biology tutor
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Describe How Speciation Occurs Through Sympatric/Allopatric Speciation and What Are the Differences Between the Methods?

The main difference to consider would be that sympatric speciation occurs in the same habitat and population while allopatric speciation requires a geographical barrier between subsets of the population. In ...
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Answered by Rana E. • Biology tutor
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In DNA, what bonds form between the nitrogenous bases

Hydrogen bonds.
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Answered by Rochelle S. • Biology tutor
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Describe the cardiac cycle, referring to the valves of the heart.

Deoxygenated blood enters the right atrium of the heart via the superior & inferior vena cavae. The atria contract and the right atrioventricular valve opens, allowing the blood to enter the right ventri...
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Answered by Thomas R. • Biology tutor
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How does an action potential travel across a cholergenic synapse?

An action potential arrives at synaptic knob. This causes voltage-gated Ca2+ ion channels to open, resulting in an influx of Ca2+ ions diffusing into the synaptic knob. This then causes vesicles containing a...
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Answered by Victoria F. • Biology tutor
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