4
(b)
marking points 1, 4, 8, 14, 19, 20 and 22 relate to the bullet points in the question
1. liquid at normal temperatures ;
2. hydrogen bonding between water molecules ;
3. molecules more difficult to separate ;
4. ice floats on water / water freezes from top down ;
5. insulates water beneath ;
6. large bodies of water don’t freeze completely / animals can still swim etc ;
7. (change in density with temperature) causes currents to circulate nutrients ;
8. solvent for , polar / ionic , substances ;
9. solubility of gases in environment ;
10. allows reactions to take place ;
11. transport medium ;
12. e.g. (of substance carried in what) ;
13. transport medium for , gametes / blood cells ;
14. water slow to change temperature ;
15. lakes / oceans / large volumes , provide thermally stable environment ;
16. internal body temperature changes minimised ;
17. used for cooling ;
18. e.g. (sweating / panting / transpiration) ;
19. large amount of energy must be removed for water to freeze ;
20. organisms can use surface of water (as habitat) ;
21. e.g. ; (of organism)
22. can form (long / unbroken) columns of water ;
23. ref. to vascular tissue / xylem ;
24. reactant (photosynthesis) ;
25. role in , hydrolysis / condensation ;
26. AVP ; e.g. transparency
27. AVP ; plants can photosynthesise under water
incompressible
hydrostatic skeleton / turgor
buoyancy
guard cell mechanism
support for large organisms on ice (penguins / polar bears)
further detail of any point
9 max
QWC – legible text with accurate spelling, punctuation and grammar; [1]
[Total :12]