Specialised cells

Your body has many kinds of cell. Each one has a special shape and parts that suit its job.

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Cells with special jobs

In a multicellular organism, most cells are specialised: they are adapted to do one job well.
They still have the usual parts (most have a nucleus, cytoplasm and a cell membrane), plus extra features.
CellJobSpecial features
Red blood cellCarries oxygenNo nucleus, so more room for haemoglobin; a disc shape, dipped in the middle, gives a large surface
Nerve cellCarries electrical impulsesVery long; branched ends connect to other cells
Muscle cellContracts to move the bodyLots of mitochondria to release energy
Ciliated cellMoves mucus in the airwaysTiny hairs (cilia) that sweep mucus up and away from the lungs

Sex cells

Sperm cell: a tail to swim, lots of mitochondria to release energy for swimming, and a head containing the nucleus plus enzymes that help it get into the egg.
Egg cell: much bigger, with lots of cytoplasm containing a food store for the early embryo.
Both carry half the usual genetic material, so a fertilised egg has a full set.

Specialised plant cells

Root hair cell: a long thin extension gives a large surface area to absorb water and minerals. It has no chloroplasts, because roots are in the dark.
Palisade cell: packed with chloroplasts and found near the top of a leaf, where it gets the most light for photosynthesis.
Under a microscope: real size = image size ÷ magnification.
Worked example

A cell's image is 4 mm across under a ×400 microscope. What is its real size?

  1. real size = image size ÷ magnification
  2. 4 ÷ 400

Answer: 0.01 mm

Key idea

Specialised cells have features that suit their job: red blood cells (no nucleus), nerve cells (long), muscle cells and sperm (lots of mitochondria), ciliated cells (cilia), root hair cells (large surface area), palisade cells (many chloroplasts).

Key words
Nucleus
The part of a cell that controls it and contains the chromosomes.
Mitochondria
The parts of a cell where aerobic respiration releases energy.
Cell membrane
The thin layer around a cell that controls what goes in and out.
Water
Pure water melts at 0 °C and boils at 100 °C. Its density is 1 g/cm³. Ice is less dense than water, so it floats.
Photosynthesis
How plants make glucose using light: carbon dioxide + water → glucose + oxygen.

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Extra practice

2 more questions

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  1. Why is a red blood cell small and flexible?

    1. To contract
    2. To absorb water
    3. To squeeze through narrow capillaries
    4. To swim
    Show the answer

    Answer: To squeeze through narrow capillaries

    Capillaries are very narrow.

  2. What is the job of the tail of a sperm cell?

    1. To store food
    2. To make chlorophyll
    3. To help it swim to the egg
    4. To carry genetic information
    Show the answer

    Answer: To help it swim to the egg

    The tail moves the sperm.

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Sources and references

Checked by the GCSE-ready editorial team, 17 October 2026. Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.

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