Chapter 8

• all organisms need to obtain substances from their environment
• leaf is the kitchen of the cell
• theres two transport systems in plants
• the two transport systems are the xylem tissue and the phloem tissue
• xylem is made of dead cells
• the xylem transport water and mineral ions
• phloem is made of living cells
• the phloem transport sucrose and amino acids
• vascular bundles are bundles made of xylem and phloem tubes
• the locations of vascular bundles:

  • root : center
  • stem : in the ring shape on the edge
• xylem has lignin
• Lignin is a hard, strong, waterproof substance that forms the walls of the xylem vessels
• xylem is unicellular
• Xylem does transportation
• Phloem does translocation
• phloem doesnt have lignin
• phloem does translocation
• xylem is unidirectional (moves in a one direction)
• phloeum is multidirectional (moves in multiple directions)
• transpiration is the loss of vapour from plant
• transpiration occurs on leaves
• roots hair function is to absorb water and mineral ions
• the water in soil moves to the root by osmosis
• the tips of root hairs have protective cap which protects the root when growing through the soil
• the rest of the root is covered with a layer of epidermis
• root hairs dont live for long due to them getting damaged by soil particles and water
• how is lignin formed?

  lignin is formed when the cell dies, and all the dead cells stick to the sides of the cellulose, which forms lignin
• the water vapour diffuses out of the leaf through the stomata (transpiration)
• water moves from the root hair cells through the root cortex, through the xylem and into the mesophyll cells in cells