This quiz contains a mix of SL and HL questions
1. What is the best definition of water potential in a plant cell?
  • A. The measure of the concentration of solutes within the cell
  • B. The potential energy of water per unit volume relative to pure water at atmospheric pressure and 20°C
  • C. The pressure exerted by water molecules on the cell wall
  • D. The ability of water to move from lower to higher solute concentration

Q2&3. The image shows two solutions separated by a semi-permeable membrane.

2 solutions seperated by semi-permeable membrane

 adapted from
H. Hoffmeister
public domain
2. In comparison to Y, region X can be described as:
  • A. Having lower water concentration
  • B. Hypertonic
  • C. Hypotonic
  • D. Having lower osmolarity 
3. Area Y can be described as ...
  • A. having higher ψw than area X
  • B. having ψw of zero
  • C. having higher ψs than area X
  • D. having lower ψw than area X

Q4-6: A student cut some potato chips and placed them in different concentrations of sucrose solution. The chips were 50 mm long at the start. After 60 minutes she remeasured the chips and plotted a graph of her results:

graph to show effect of concentration of sucrose on potato chip size

potato chip section
4. Using the graph, at which sucrose concentration is a dynamic equilibrium reached?
  • A. 0.0%
  • B. 1.0%
  • C. 1.2%
  • D. 2.0%
5. 0.0% sucrose concentration can be described as:
  • A. Isotonic to the potato cells
  • B. Having a positive solute potential (ψs)
  • C. Hypertonic to potato cells
  • D. Having a water potential (ψw) roughly equal to zero
6. Which of the following would not be an improvement of the investigation?
  • A. Carrying out repeats at each concentration
  • B. Adding error bars to the graph which show variability of repeats
  • C. Measuring both mass and length change
  • D. Increasing the intervals of sucrose concentrations studied

7. A similar experiment was repeated using red onion. The image below is a light micrograph of a sample of the red onion cells in 2.0% sucrose solution.

red_onion_cells

Compared to the start of the investigation, which description(s) apply to cell X?

I. Water potential has decreased inside the cell
II. Solute potential has become more negative inside the cell
III. Pressure potential has increased inside the cell
IV. Solute concentration has increased inside the cell
Wikimedia
CC-BY-SA 3.0
  • A. I only
  • B. IV only
  • C. I, III and IV only  
  • D. I, II and IV only

8. The image shows a light micrograph of red blood cells taken from a patient following an intravenous solution being given.

red_blood_cells

 Ed Uthman from Houston, TX, USA
CC-BY-SA 2.0
Which cell appearance would be compatible with the patient having been given a hypotonic solution intravenously?
  • A. I only
  • B.  II only
  • C.  I and II only
  • D. I and III only

Q9+10: The Image below shows a paramecium, a unicellular freshwater organism.

Paramecium organism

 Barfooz at the English Wikipedia.
CC-BY-SA 3.0
9. What structure is X?
  • A. Lysosome
  • B. Nucleus
  • C. Contractile vacuole
  • D. Mitochondrion
10. The paramecium is anaesthetised so that X can no longer function, then it is placed in distilled water. What is the likely outcome?
  • A. The paramecium will burst due to water moving down its potential gradient
  • B. The paramecium will become turgid due to water moving down its potential gradient
  • C. The paramecium will shrink due to water moving down its potential gradient
  • D. Structure X will get smaller due to water moving down its potential gradient