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a) Compare the differences between an artery and a vein. b) List and explain 2 features that allow capillaries to exchange substances efficiently.

a) Veins have a larger lumen and a thinner wall as they carry blood at a lower pressure than the blood in arteries. Due to this low pressure, veins have valves to assist with the continuous movement of blood...
ZG
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How do vaccinations work and what is their role in herd immunity?

Vaccinations are given to provide immunity and protection against a certain disease or pathogen. The vaccine itself contains a weakened 'version' of the pathogen that retains its antigens but not its ability...
Answered by • Human Biology tutor
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Which of the following is an exchange vessel? A. Capillary B. Elastic artery C. Lymphatic D. Muscular artery E. Vein

A. Capillary
Answered by • Human Biology tutor
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Name and briefly describe four methods in which molecules and ions may pass through a cell membrane?

A. Osmosis - the movement of water down a water potential gradient through a partially permeable membrane. B. Diffusion - the net movement of molecules or ions down a concentration gradient. C. Active Transp...
Answered by • Human Biology tutor
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Describe the conduction system of the heart and explain how the atria and ventricles contract sequentially.

The heart consists of four chambers, two atria and two ventricle. The conduction system of the heart mediates synchronised contraction of the chambers to allow the heart to effectively pump blood. The conduc...
CS
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