Plant Cell Specialisation

• Most plant cells are specialised. They have special adaptions which help them carry out their particular function. When cells become specialised, we call that process differentiation.
• What features do plant cells have, that animal cells do not?

  Cellulose cell wall

  Permanent vacuole

  Chloroplasts
• ROOT HAIR CELLS

  These hairs increase the surface area of the root, so it can absorb water and dissolved minerals more effectively.

  The root hair increases the surface area of the root.

  Root hair cells do not contain chloroplasts because they are underground and photosynthesis requires energy from light.

  They contain a cell wall, a permanent vacuole and a nucleus.
• XYLEM CELLS

  Xylem are found in the plant stem. They form long tubes. These tubes carry water and dissolved minerals from to the leaves.

  Xylem cells have very thick walls containing lignin. This provides support to the plant. Because the cell walls are sealed with lignin, this causes the xylem cells to die.

  The end walls between the cells have broken down. This means that the cells now form a long tube so water and dissolved minerals can flow easily.

  Xylem cells have got no nucleus, cytoplasm, vacuole or chloroplasts. That makes it easier for water and minerals to flow.
• PHLOEM CELLS

  Phloem tubes carry dissolved sugars up and down the plant.

  Phloem vessel cells have no nucleus and only limited cytoplasm.

  The end walls of the vessel cells have pores called sieve plates.

  These features allow dissolved sugars to move through the cell interior.

  Each phloem vessel cell has a companion cell connected by pores.

  Mitochondria in the companion cell provide energy to the phloem vessel cell.