Top answers

Describe the differences between different types of blood vessels

Capillaries-one cell thick, minimal diffusion distanceveins-wise lumen, many elastic fibres, valves presentarteries-thick muscular layer to withstand BP
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Answered by Bela V. • Biology tutor
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How are blood vessels fit for purpose?

Arteries - carry blood at high pressure away from the heart. Their narrow lumen and thick, muscular wall allows them to do this effectively. The elastic, muscular wall allows for expansion and relaxation of ...
AT
Answered by Anna T. • Biology tutor
4419 Views

Explain how enzymes work.

Worth four marks Enzymes are biological catalysts which are used in reactions. A reaction will typically involve an enzyme and a substrate. Enzymes are complementary to the substrate they combine to form an ...
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Answered by Moyo K. • Biology tutor
3964 Views

Explain how glucose is made during photosynthesis and how it is utilised by the plant.

During photosynthesis, green plants use carbon dioxyde and water, and with light energy convert them to glucose and oxygen. There are two phases of this process, the light-dependent phase which needs the ene...
AS
Answered by Anna S. • Biology tutor
20207 Views

Define osmosis

Osmosis is the passive movement of water from an area of high water concentration (dilute solution) to an area of low water concentration (concentrated solution) across a partially permeable membrane down th...
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Answered by Josephine S. • Biology tutor
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