Skip to content
InkFlaskCambridge IGCSE

Pupil sheet · Blood

Blood — final check

Name ______________________ Date ____________

Work alone, with the lesson closed. Answer every question; there are no hints.

1. state / give

(a) State the four components of blood. (b) The drawing shows part of a stained blood smear, as you would see it in a photomicrograph. Give the letter of a red blood cell and the letter of a white blood cell, and one feature of each that you used.

A drawing of part of a stained blood smear as seen at ×400, with a 10 µm scale bar. Most of the field is filled with pink discs about 7.5 µm across, each paler in the middle and with no nucleus; a few tiny purple specks lie between them. Four parts are lettered. E: a cell about 11 µm across with grainy lilac cytoplasm and a purple nucleus in four rounded lobes joined together. F: one of the pink discs. N: one of the tiny purple specks, about 2.5 µm across. W: a cell about 9 µm across, almost filled by one large round purple nucleus, with a thin pale rim.

(a) The four components

(b) Red cell: letter and feature; white cell: letter and feature

2. give / describe

Supplement. In the drawing of the smear, one lettered part is a lymphocyte and one is a phagocyte. Give the letter of each, and describe the feature that shows which is which.

A drawing of part of a stained blood smear as seen at ×400, with a 10 µm scale bar. Most of the field is filled with pink discs about 7.5 µm across, each paler in the middle and with no nucleus; a few tiny purple specks lie between them. Four parts are lettered. E: a cell about 11 µm across with grainy lilac cytoplasm and a purple nucleus in four rounded lobes joined together. F: one of the pink discs. N: one of the tiny purple specks, about 2.5 µm across. W: a cell about 9 µm across, almost filled by one large round purple nucleus, with a thin pale rim.

3. explain

A person has anaemia: their blood has fewer red blood cells than normal, so it holds less haemoglobin. Explain why they often feel tired and weak.

4. state

Supplement. State the function of lymphocytes and of phagocytes.

(a) Lymphocytes

(b) Phagocytes

5. identify

Which row shows the functions of white blood cells, platelets and plasma?

RowWhite blood cellsPlateletsPlasma
Aphagocytosis and antibody productiontransport oxygentransports urea and hormones
Bclottingphagocytosis and antibody productiontransports urea and hormones
Cphagocytosis and antibody productionclottingtransports urea and hormones
Dphagocytosis and antibody productionclottingtransports haemoglobin and oxygen

Circle one answer.

  • A
  • B
  • C
  • D

6. state / suggest

When the bark of a pine tree is cut, sticky resin flows into the wound and hardens over it. The hardened resin does the same two jobs for the tree as a blood clot does at a cut in the skin. For each role of a blood clot, state the role and suggest how the resin does the same job for the tree.

(a) First role, and the resin's job

(b) Second role, and the resin's job

7. explain

Supplement. A pupil writes: "At a cut, soluble fibrin in the plasma is converted into fibrinogen, which forms a mesh of threads." Explain why this is incorrect.