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If a gene mutation is associated with the development of Alzheimer's Disease (e.g. E280A), how might a high frequency develop in a population and why wouldn't natural selection decrease it?

A high frequency of mutation can be produced by having a small population, leading to high levels of inbreeding. When there is little interbreeding with different populations, the genetic diversity will rema...
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Answered by Caitlin R. • Biology tutor
2912 Views

How can DNA mutations alter the structure of a protein?

Regions of an organism's genome that code for proteins are known as genes. The sequence of deoxyribonucleic acids (bases) in a gene directly translates to the sequence of amino acids in the protein it encode...
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Answered by Lewis B. • Biology tutor
3949 Views

Describe 2 ways in which the body prevents entry of microorganisms into the body

-acid in the stomach kills any pathogens-skin acts as a physical barrier to pathogens-hair in the nose and ears trap any pathogens -saliva & mucous trap pathogens. The bronchi have villi that help move p...
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Answered by Sara H. • Biology tutor
4301 Views

Describe the pathway of electrical activity in the heart during the cardiac cycle.

The wave of excitation originates in the sinoatrial node in the right atrium. From there, it travels through the right and left atria, causing contraction of the atria (atrial systole). It is prevented from ...
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Answered by Josh W. • Biology tutor
3690 Views

What happens in the light dependent reaction in photosynthesis?

Background Photosynthesis is the process where energy from light is used to break apart bonds in water . Hydrogen from water is then combined with CO2 to form glucose which is stored in the plant as a fuel f...
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Answered by Hannah W. • Biology tutor
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