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Describe the structure of the DNA of a eukaryotic cell

DNA is a double stranded helix. Each strand is held together by complementary base pairs or nucleotides. A nucleotide consists of a base, a deoxyribose sugar and a phosphate. The bases are A, T, C and G. G a...
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Answered by Annie E. • Biology tutor
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Give 2 methods of transmission of disease and an example for each

Transmission is the way in which a disease is spread. Transmission of disease can occur in multiple ways. Two methods of this are:1)- vector transmission 2)- waterAn example of vector transmission is tubercu...
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Answered by Judith S. • Biology tutor
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Explain how skeletal muscle contracts.

Muscle fibers are comprised of elongated myofibrils. A myofibril is made of repeating chains of sarcomeres which have no nucleus but have myosin and actin filaments which are able to slide past each other du...
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Answered by Daniel R. • Biology tutor
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How do blood vessels help to control body temperature.

Body temperature must be maintained around 37°C as the enzymes in our body work best at this temperature. The thermoregulatory centre in the brain contains receptors that detect the temperature of blood, as ...
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Answered by Thivija S. • Biology tutor
9717 Views

Describe what is meant by the 'lock and key' theory.

When binding two things together in biology, such as an enzyme and a substrate, in order to fit together they musth ave a specific shape. The shape of the enzyme active site must be the reciprocal to the sha...
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Answered by Lily W. • Biology tutor
5348 Views