lqc 2b exam qs

Question 1

give three ways in which xylem tissue is adapted for its function

Answer 1

-wide/large cross-sectional area to transport large volume of water
-empty cells/ no cytoplasm so low resistance to flow
-thickening of the wall/ lignification that strengthens the wall to prevent collapse

Question 2

Explain how secondary thickening in the cell wall contributes to the physical properties of xylem vessels.

Answer 2

• secondary thickening provides greater tensile strength
  -secondary thickening provides extra rigidity
  -lignin provides waterproofing