Transport in Plants

Question 1

why do plants need transport systems?

Answer 1

• meet their metabolic demands
• size+continous growth=down SA:V ratio=x just rely on diffusion

Question 2

xylem: function+structure

Answer 2

• function
• transport water+minerals
• structure
• xylem vessels=end walls dissapear during development=continous tube & lignin is deposited in rings/spirals/pits/reticulate
• xylem parenchyma=storage+may contain tannin
• xylem fibres=lignified secondary walls=mechanical strength
• non-living=oraganelles disappear as it develops=needs to be strengthened

Question 3

phloem: function+structure

Answer 3

• function
• transports solutes eg. sucrose/amino acids
• structure
• sieve tube elements=end walls perforated=sieve plate & make up a sieve tube=cylindrical column
• living cell=has cytoplasm but other organelles disappear as it differentiates
• companion cells=associated w 1 or 2 sieve plates+contain many mitochondria=produces ATP=active transport+plasmodesmata fund bw these+sieve tube elements=ATP can permeate into all phloem