IB Biology SL A1.1 Water Question Bank

a. two hydrogens and one oxygen;

b. ( 2 hydrogen and 1 oxygen) linked by single lines to represent bonds placed at an angle;

a. cohesion is caused by the polarity of water

OR

water molecules have a negative and positive end;

b. water molecules are attracted to each other

OR

water molecules are linked by hydrogen bonds;

c. (cohesion) enables water to move along stems/xylem

OR

enables a continuous column of water in transpiration/transpiration pull;

d. surface tension provides a habitat for some organisms

OR

some insects can walk on water surface because of surface tension/other verified example OR

cohesion is related to buoyancy allowing organisms (like ringed seal) to float;

e. helps animals regulate body temperature (through evaporative cooling);

f. (cohesion causes high specific heat) so maintains a stable temperature in aquatic environments

OR

water is liquid at a wide range of temperatures supporting many aquatic habitats;

4

Marking guidance:

max

B