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What are the structural and functional differences between arteries and veins?

Arteries have a much thicker muscular layer than veins, as this allows them to contract strongly and generate a high pressure to allow blood to be quickly transported to tissues in the body. Arteries also ha...
AR
Answered by Anita R. • Biology tutor
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Name and outline the two types of circulatory systems

A single circulatory system is where blood flow starts with deoxygenated blood being pumped by the heart to the lungs or gills and then travelling directly to the rest of the body’s tissues. Found in fish an...
BS
Answered by Bianca S. • Biology tutor
8267 Views

How does an action potential work?

Resting potential at - 75mV Stimulus causes opening of sodium channels and influx of sodium ions, membrane becomes less polarized Threshold potential reached at -55mV, opening of many more sodium channels, g...
CH
Answered by Catherine H. • Biology tutor
3458 Views

What is the electron acceptor used in photosynthesis

NADP
BS
Answered by Bianca S. • Biology tutor
3305 Views

How is a polar bear adapted for it's environment? (4 marks)

Polar bears are well adapted for survival in the Arctic: White fur to camouflage themselves from prey on the snow and ice. Thick layers of fat and fur for insulation against the cold. Small surface area to v...
RM
Answered by Ruwani M. • Biology tutor
10578 Views