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Describe the principle of Polymerase Chain Reaction (PCR) and its application in laboratory setting.

Polymerase Chain Reaction is an in vitro method used to amplify DNA fragments. It consists of three main steps, which are: (1) denaturing, (2) annealing, (3) and extension. During denaturation, the double-st...
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How is the cardiac cycle regulated by the heart itself?

The heartbeat is started at a specialised area of the right atrium, known as the sinoatrial node (SAN) ; the SAN sends out the waves of depolarisation, resulting in contraction of the cardiac muscle. These w...
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Answered by Emma B. • Biology tutor
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Explain the main structures of a human cell.

A human cell is made up of:Cell Membrane: provides structure for the cell and controls what goes in and outCytoplasm: Jelly like liquid which contains the organellesNucleus: Contains DNAMitochondria: Make AT...
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Answered by Adham C. • Biology tutor
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Explain why the body tenses up in rigor mortis

This is because when an organism dies there is no source of ATP, without this source of ATP ant myosin heads attached to the actin binding site cannot detach therefore leaving the muscles in a contracted sta...
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How does natural selection occur?

A population of organisms exists with a set range of alleles. In an organism, a random mutation can result in the formation of a new allele. Some mutated alleles can be beneficial to an organism, and increas...
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Answered by Thendrral P. • Biology tutor
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