Xylem

Question 1

Xylem:

Answer 1

Tissue transports water and dissolved mineral ions from the roots up to the leaves/other parts of the plant.

Question 2

Adaptations/structure:

Answer 2

• The cells are impregnated with lignin.
• Lignification and makes them waterproof.
• Thickening provides strength/support (to cell walls) – prevents collapse inwards from tension
  created by transportation pull.
• Narrow tubes allows adhesion/capillary action to form continuous column of water.
• Lignin deposited in the walls in spiral patterns allows xylem to flex as plant grows and enables stem to bend.
• Dead cells aligned end to end to form a hollow continuous column
• The end of cell walls and contents decay leaving a long column of dead cells with no contents (no
  cytoplasm).
• Bordered pits in lignified walls (where lignification is incomplete – gap), allow water (and ions) to
  move sideways from on vessel to another, and to leave xylem and pass to rest of plant.
• Living parenchyma cells which act as packaging tissue to separate and support the vessels.