Question 1
State the four components of blood.
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- red blood cells (1)
- white blood cells (1)
- platelets (1)
- plasma (1)
Question 2
Plasma transports many substances around the body. Give three substances that are transported by plasma.
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- carbon dioxide (1)
- digested food / glucose / amino acids (1)
- urea (1)
- hormones (1)
- heat energy (1)
- Max 3
Question 3
Which feature of a red blood cell increases the amount of oxygen it can carry?
- A large nucleus
- A thick cell wall
- Haemoglobin inside the cell
- Many mitochondria
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Answer: C (1)
Question 4
Explain how three adaptations of red blood cells make them suitable for transporting oxygen.
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- biconcave shape gives a large surface area for oxygen to diffuse in and out (1)
- no nucleus, so there is more room for haemoglobin (1)
- contains haemoglobin which combines with oxygen (1) allow forms oxyhaemoglobin
Question 5
Lymphocytes release antibodies when a pathogen enters the body. Explain why an antibody that works against one pathogen does not work against a different pathogen.
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- antibodies are specific (1)
- the shape of the antibody fits the antigen on that pathogen only (1)
- a different pathogen has different antigens, so a different antibody is needed (1)