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Why do we vaccinate people - how does it work?

Vaccination is an important method used in healthcare to prevent people from getting certain diseases. Vaccines contain a dead or weakened ( attenuated) form of a pathogen, and the immune system responds to ...
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Answered by Ella S. • Biology tutor
4188 Views

Explain the principles of PCR

The Polymerase Chain Reaction (PCR) is a method of DNA amplification in vitro. It consists of 3 stages - denaturation, annealing and extending. PCR relies on the use of a thermophilic Taq polymerase enzyme.
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Answered by David B. • Biology tutor
5451 Views

State the differences between introns and exons.

Introns and exons are parts of genes - exons code for proteins, whereas introns do not, ie: exons are converted into messenger RNA to allow these parts of the gene to then be transcribed into protein. Intron...
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Answered by David B. • Biology tutor
14252 Views

Name the major organs of the Gastrointestinal tract

Oral cavity, Oesophagus, Stomach, duodenum, jejunum, ileum, colon, rectum, anus.
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Answered by David B. • Biology tutor
3141 Views

Explain what is meant by active transport

Avtive transport is the transport of molecules against their concentration gradient (that is, from a low concentration to a high concentration). This mechanism requires energy, and so ATP is used up.
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Answered by Arantxa B. • Biology tutor
4373 Views