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IGCSEBiology
Trial Class

Original practice · 5 questions · 15 marks · about 17 minutes

Blood Components and Functions Practice Questions

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

These questions test your knowledge of the four main components of blood and their specific functions.

Before you open the answers

  • Attempt every question without notes.
  • Show working for calculations and write complete biological statements.
  • Use the suggested time as a guide, not a strict limit on the first attempt.

These are original practice questions. They do not reproduce an official Cambridge paper or official mark scheme.

  1. Question 1

    Paper 2 Both 4 marks Difficulty 2/5

    Name the four main components of blood and state one function of each.

    Show model answer and marking guidance
    1. Red blood cells: transport oxygen (as oxyhaemoglobin).
    2. White blood cells: defend against pathogens / immune response.
    3. Platelets: involved in blood clotting at wound sites.
    4. Plasma: transports dissolved substances (glucose, CO₂, urea, hormones).

  2. Question 2

    Paper 4 Extended 3 marks Difficulty 3/5

    Describe how phagocytes and lymphocytes protect the body against infection in different ways.

    Show model answer and marking guidance
    1. Phagocytes engulf and digest pathogens by phagocytosis.
    2. Lymphocytes produce antibodies that are specific to antigens on the pathogen.
    3. Antibodies cause pathogens to clump together (agglutination) or mark them for destruction.

  3. Question 3

    Paper 4 Both 3 marks Difficulty 3/5

    State three substances transported in blood plasma.

    Show model answer and marking guidance
    1. Carbon dioxide (from cells to the lungs as dissolved CO₂ or hydrogencarbonate ions).
    2. Urea (from the liver to the kidneys for excretion).
    3. Glucose / amino acids / hormones (to cells that need them).

  4. Question 4

    Paper 2 Core 2 marks Difficulty 1/5

    State the name of the protein in red blood cells that carries oxygen.

    Show model answer and marking guidance
    1. Haemoglobin.
    2. It combines with oxygen to form oxyhaemoglobin in the lungs.

  5. Question 5

    Paper 4 Extended 3 marks Difficulty 4/5

    Explain why a person with a low platelet count may bleed for longer than normal after a cut.

    Show model answer and marking guidance
    1. Platelets are needed to start the clotting process at a wound.
    2. They release chemicals that trigger the conversion of fibrinogen to fibrin.
    3. With fewer platelets, the clotting cascade is slower: a fibrin mesh takes longer to form.

Mark the set consistently

Award a point only when the idea is clearly present in the written answer. Correct any missed point in a complete sentence, then test the same skill on a different question several days later.

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