Question 1
Which component of blood transports urea?
- Red blood cells
- Platelets
- Plasma
- White blood cells
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Answer: C (1) Plasma transports urea
Question 2
List the four components of blood.
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- red blood cells, white blood cells (1)
- platelets, plasma (1)
Question 3
Describe two features that help you to identify a red blood cell in a photomicrograph.
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- no nucleus (1)
- small / round / pale in the middle / more numerous (1)
- allow biconcave shape
Question 4
State the function of (a) red blood cells, including the role of haemoglobin, (b) white blood cells, (c) plasma.
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- (a) transport oxygen (1)
- haemoglobin combines with oxygen (1)
- (b) phagocytosis and antibody production (1)
- (c) transports blood cells / ions / nutrients / urea / hormones / carbon dioxide (1)
Question 5
State two roles of blood clotting.
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- prevents blood loss (1)
- prevents entry of pathogens (1)
Question 6
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanDescribe the process of blood clotting.
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- fibrinogen is a soluble protein in plasma (1)
- fibrinogen is converted to fibrin (1)
- fibrin is insoluble / forms fibres (1)
- fibres form a mesh that traps red blood cells to form a clot (1)
Question 7
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanA photomicrograph shows two types of white blood cell. One has a large round nucleus filling most of the cell. The other has a lobed nucleus. Name each type and state its function.
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- large round nucleus = lymphocyte (1)
- produces antibodies (1)
- lobed nucleus = phagocyte (1)
- engulfs pathogens / phagocytosis (1)