Xylem and Phoem: elements and functions

Question 1

state the function of xylem

Answer 1

• transports water and mineral ions
• structural support
• food storage

Question 2

state where the xylem is located in the leaf, stem and root cross-sections

Answer 2

root: cross like shape in centre
stem: inward facing part of vascular bundle
leaf: upward facing part of vascular bunde

Question 3

state function of phloem

Answer 3

-transports assimilates

Question 4

state the what the xylem tissue is made up of

Answer 4

• tracheids
• xylem vessel elements
• parenchyma cells
• sclerenchyma cells

Question 5

describe and explain the structure and function of xylem vessel elements

Answer 5

1. lignified walls: adds strength to withstand hydrostatic pressure, impermeable to water
2. no end-plates: ensures mass flow of water and dissolved solutes as adhesive and cohesive forces are not impeded/obstructed
3. no protoplassm: doesn’t obstruct/impede mass flow of water and dissolved solutes
4. pits in wall: lateral movement of water and allows continuous flow of water in case air bubbles are formed
5. helps prevent water column from breaking and assists capillary action

Question 6

state what cells are found in the phloem tissue

Answer 6

• companion cells
• sieve tube lements
• parnechyma

Question 7

describe and eexplain structure and function of sieve tube elements

Answer 7

1. sieve plates: allow continuus flow of water
2. cellulose cell wall: strengthens wall to withstand hydrostatic pressure
3. no nucleus, vacuole or ribosomes: maximises space for translocation
4. thin cytoplasm: reduces friction to facilitate movement of assimilates