Specialised plant cells
Joe Wolfensohn
Teacher
Contents
Recall Questions
This topic requires prior knowledge of plant cell structures to understand how specialisation enables roles such as transport and photosynthesis.
Which part of the cell carries out photosynthesis?
Chloroplast
Which part of the cell maintains the shape of the cell?
Cell wall (and the vacuole maintains pressure inside the cell)
Plant cells don't have mitochondria. True or False?
False. Plant cells have mitochondria which are the site of aerobic respiration.
Topic Explainer Video
Check out this @JoeDoesBiology video that explains specialised plant cells, then read the study notes. Once you’ve gone through them, don’t forget to try the practice questions!
Specialised Plant Cells
Root Hair Cell
Function: Absorb water and mineral ions from the soil.
Adaptations:
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Long extension (‘root hair’) – increases surface area for absorption.
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No chloroplasts – not needed underground where there is no light and therefore no photosynthesis.
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Many mitochondria – Release energy from respiration for active transport.
Palisade Mesophyll Cell
Function: Carry out photosynthesis.
Adaptations:
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Packed with chloroplasts – absorb more light energy for photosynthesis.
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Located near top of leaf – absorbs maximum sunlight.
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Box-shaped and tightly packed – maximise surface area for light absorption.
Xylem Cell
Function: Transport water and minerals from roots to leaves; provide support.
Adaptations:
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No end walls – forms a continuous hollow tube.
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Walls strengthened with lignin – for structural support and waterproofing.
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No cytoplasm or nucleus – allows free flow of water.
Because the cells have no cytoplasm, nucleus or end cell walls, they are dead cells
Phloem Cell
Function: Transport sugars (mainly sucrose) both up and down the plant in a process called translocation.
Adaptations:
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No nucleus and very little cytoplasm, allow unrestricted flow of sugars.
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Sieve plates – with pores to allow movement of sugars between cells.
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Companion cells (next to phloem cells) – contain many mitochondria to release energy.
Key Term
- Differentiation - the process by which cells become specialised.
No answer provided.
Exam Tip
- Always match the adaptation to the function – this is how marks are awarded in exam questions.
No answer provided.
Practice Question
Explain how root hair cells are adapted for their function. (2 marks)
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Root hair cells have a long extension to
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increase surface area for absorbing water and minerals.
or -
They have many mitochondria
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For respiration / energy release for active transport.
More Practice
Try to answer the practice question from the TikTok on your own, then watch the video to see how well you did!