91热爆

Key points

  • Cells are the fundamental unit of all living things.
  • Specialised plant cells have components that allow them to complete a specific purpose.
  • Specialised plant cells include root hair cells, palisade cells, xylem cells and phloem cells.
Back to top

Video - Specialised plant cells

Learn about specialised plant cells

Can you answer these questions based on the video?

1. What are the three main components of plant cells?

2. What are the three components of plant cells that are not found in animal cells?

Back to top

Root hair cells

A photo showing lots of tiny hairs on the roots of water cress
Image caption,
Tiny hairs on the roots of water cress

Roots hold plants in place as they grow and also absorb water and minerals from the soil. Roots divide into smaller and smaller branches as they travel into the soil. The outside surface of roots are covered with root hair cells, which have tiny 'hairs' which poke into the soil. This massively increases the surface area for the root hair cell to absorb more water and minerals.

A photo showing lots of tiny hairs on the roots of water cress
Image caption,
Tiny hairs on the roots of water cress
An infographic showing root hair cells absorbing water and minerals through thin hairs that stick outwards
Back to top

Palisade cells

A photo of green plant cells packed together as seen through a microscope
Image caption,
These plant cells are packed with green chloroplasts

When the Sun shines, in plant cells makes sugar for growth, reproduction and other life processes. Photosynthesis occurs in a special chemical called , which is found in parts of plant cells called . Palisade cells are the major site of photosynthesis. They are well adapted for this function because:

  • they are towards the tops of leaves for maximum light
  • they have lots of chloroplasts
A photo of green plant cells packed together as seen through a microscope
Image caption,
These plant cells are packed with green chloroplasts
An infographic showing a green palisade cell, packed with small parts called chloroplasts
Back to top

Xylem and phloem cells

  • Xylem cells transport water from the roots to other parts of the plant.
  • Phloem cells transport sugary water from the leaves to the rest of the plant.
An infographic of the inside of a stem and a root, showing the xylem and phloem cells next to each other

Xylem

Xylem cells run inside stems of plants from their roots to their leaves. Xylem cells die and their ends break down. This allows them to form long tubes to carry water upwards for photosynthesis. They have thick cell walls to provide support to the plant. This holds the leaves up for photosynthesis and the flowers up for reproduction.

A photo showing how red water has travelled up a stick of celery and colouring the leaves red
Image caption,
The xylem cells in this stick of celery are carrying the red inky water up to the leaves

Phloem

Phloem cells are often found near to xylem cells in the stem. Unlike xylem cells, phloem cells are alive. They carry sugary water from the leaves to the rest of the plant. Next to the phloem cells are companion cells which have many . Here occurs to release energy from glucose to transport sugar and other substances in the phloem.

Back to top

Test your knowledge

Quiz

Test questions

Write a paragraph to answer each of the following questions. Tap 'Show answer' to see some points you could have included.

Describe the adaptations of root hair and palisade cells.

Describe the purpose and adaptations of xylem and phloem cells.

Back to top

Play the Atomic Labs game! game

Try out practical experiments in this KS3 science game.

Play the Atomic Labs game!
Back to top

More on Living organisms

Find out more by working through a topic