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Explain how hydrogen bonding occurs between molecules of water.

Hydrogen Bonding occurs between 2 adjacent molecules of H 2 O. The polar covalent bond between oxygen and hydrogen creates negative and positive partial charges respectively. There is a weak intermolecular f...
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Answered by Tom H. • Biology tutor
18279 Views

Why do different blood vessels have different lumen sizes (relative to their overall size)?

Lumen sizes in blood vessels differ due to the differing functions of the vessels themselves. Arteries have to carry oxygenated blood away from the heart to the tissues at high pressure. Small lumen (relativ...
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Answered by Jessica S. • Biology tutor
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How is a nerve impulse transmitted along a synapse?

The nerve impulse arrives at the synapse. This triggers vesicles to release chemical messengers (neurotransmitters) into the synapse. These chemicals diffuse across the synapse and bind with membrane recepto...
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Answered by Alex H. • Biology tutor
3452 Views

Can you explain the food chain?

You always start with the sun which gives its every to grass which is a producer of energy. The arrow in the food chain, therefore, travels in the direction the energy travels in (in this case from the sun t...
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Answered by Amelia H. • Biology tutor
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Amy has cystic fibrosis which is caused by a recessive allele. Her partner is heterozygous for cystic fibrosis. What is the chance that her future child has cystic fibrosis?

Alleles are different forms of a gene which can become mutated to cause different characteristics or diseases. They can be dominant (usually denonimated by a captial letter H) or recessive (usually denominat...
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Answered by Rebecca M. • Biology tutor
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