Skip to content
Dabour HubLEARN · PRACTICE · EXPLORESign inStudent

1.3Unit 1: Cells and organisms

Specialised cells

5 min read 7 parts Lesson 3 of 4 1 quiz

0%read
Lesson summary

1.3 Specialised cells — CHECKPOINT BIOLOGY 0893 notes: Explain how the structure of specialised animal and plant cells is adapted to their functions.The function of a cell is the job it does, or the role it plays.A specialised cell has a structure that helps it do its function ve…

  • Root hair cells
  • Palisade cells
  • Sperm cell
  • Xylem cells
  • Haemoglobin
  • A specialised cell has a structure that helps it do its function very well

Section 1 of 7What specialised means

  • The function of a cell is the job it does, or the role it plays.
  • A specialised cell has a structure that helps it do its function very well.
  • A specialised cell is also described as adapted to its function.
  • The body has many different kinds of cell, and each kind has a particular function.
  • Structure explains function in every answer.

Section 2 of 7Red blood cells

  • Function
    • carry oxygen around the body.
FeatureHow it helps
Smaller than most other cellsLets it squeeze through tiny blood capillaries to reach every part of the body
Cytoplasm contains haemoglobin, a red pigmentHaemoglobin carries the oxygen
No nucleusLeaves more space for haemoglobin

Section 3 of 7Neurones (nerve cells)

  • Function
    • carry electrical signals from one part of the body to another so the parts can communicate.
    • Signals can pass from the brain to a muscle to make the muscle move.
FeatureHow it helps
Axon, a very long strand of cytoplasmElectrical signals travel along it quickly over long distances
Dendrites, short strands of cytoplasmCollect electrical signals from other nearby nerve cells

Section 4 of 7Ciliated cells

  • Cilia = tiny threads like microscopic hairs along one edge of the cell, which can move.
  • Ciliated cells line the tubes leading from the mouth to the lungs.
  • Other cells in this lining make mucus, a sticky substance.
    • Mucus traps dust and bacteria when breathing in, so they do not reach the lungs.
    • The cilia sweep the mucus up to the back of the mouth, where it is swallowed.

Section 5 of 7Specialised plant cells

1Root hair cells4 points
  • absorb water from the soil.
  • A long, thin extension gives a large surface area, so water moves easily into the cell.
  • Water moves through the cell wall, the cell membrane, the cytoplasm and into the sap vacuole.
  • They have no chloroplasts because roots are underground in the dark and cannot photosynthesise.
2Palisade cells3 points
  • found in leaves, where they make food by photosynthesis.
  • They contain many chloroplasts with chlorophyll that absorbs energy from sunlight.
  • They are packed near the top of the leaf to absorb as much light as possible.

Section 6 of 7Other specialised cells

  • Sperm cell
    • carries the male genetic material to the egg.
    • It has a tail to swim and many mitochondria to release energy for swimming.
  • Egg cell
    • large, with a food store in its cytoplasm for the developing embryo.
  • Xylem cells
    • form long hollow tubes that carry water up the plant.
    • The cells are dead and have no end walls.

Section 7 of 7Features shared by animal cells

  • Red blood cells, neurones and ciliated cells all have a cell membrane and cytoplasm.
  • They are animal cells because they have no cell wall, chloroplasts or large vacuole.

Last updated: