Transport in plants

Question 1

Define dicotyledonous

Answer 1

a plant where 2 leaves are the first to come from the seed

Question 2

Why are plant transport systems needed?

Answer 2

• METABOLIC DEMANDS (02 + glucose transported to places that don’t photosynthesise, hormones to places they affect, mineral ions from roots to cells that make proteins etc)
• SIZE (perennial plants need to transport everything right from root tip to leaf tip)
• SURFACE AREA : VOLUME RATIO (relatively small so can’t rely on diffusion alone for all the cells needs to be met)

Question 3

Describe the structure and function of the xylem in herbaceous dicots

Answer 3

• long hollow structure made of columns of non-living cells fusing end to end
• xylem parenchyma packs around a vessel, storing food and containing tannin deposits (protects plants from herbivores)
• lignin laid in walls of xylem in rings/spirals/ solid tubes with small unlignified areas (bordered pits) where water leaves the xylem moves into other cells of the plant.
• ## its in charge of water and mineral ions and it supports the plants