ThatQuiz Test Library Take this test now
Water potential - Quiz
Contributed by: Woolley
  • 1. What is water potential?
A) The total mass of water in a specific volume.
B) The speed at which water evaporates from a surface.
C) The chemical formula representing pure water.
D) The potential energy of water per unit volume relative to pure water in reference conditions.
  • 2. What does water potential quantify?
A) The exact temperature at which water boils.
B) The tendency of water to move from one area to another.
C) The weight of a plant root system.
D) The amount of dissolved oxygen in a body of water.
  • 3. Which of the following is a factor that causes water to move according to the text?
A) Sound waves
B) Light intensity
C) Magnetic fields
D) Osmosis
  • 4. Which matrix effect is specifically mentioned as causing capillary action?
A) Thermal expansion
B) Surface tension
C) Electrical conductivity
D) Viscosity
  • 5. In which of the following is the concept of water potential useful?
A) Determining the nutritional value of plant leaves
B) Measuring the atmospheric pressure on mountains
C) Calculating the speed of sound in aquatic environments
D) Understanding water movement within plants, animals, and soil
  • 6. How is water potential typically expressed?
A) Volume per unit time
B) Force per unit length
C) Potential energy per unit volume
D) Mass per unit area
  • 7. Which Greek letter is very often used to represent water potential?
A) β
B) α
C) δ
D) ψ
  • 8. What effect does the addition of solutes have on water potential?
A) Lowers the potential
B) Has no effect on the potential
C) Increases the potential
D) Neutralizes the potential completely
  • 9. What vector type is associated with the addition of solutes to water potential?
A) Positive vector
B) Neutral vector
C) Negative vector
D) Scalar vector
  • 10. What effect does an increase in pressure have on water potential?
A) Increases the potential
B) Lowers the potential
C) Destroys the potential
D) Keeps the potential constant
  • 11. What vector type is associated with an increase in pressure in water potential?
A) Positive vector
B) Inverted vector
C) Zero vector
D) Negative vector
  • 12. If flow is not restricted, how does water move in relation to water potential?
A) From lower water potential to higher water potential
B) From higher water potential to lower water potential
C) Only horizontally between equal potentials
D) Randomly regardless of water potential
  • 13. What type of water potential do solutions with dissolved salts, like seawater, have relative to pure water?
A) Positive water potential
B) Infinite water potential
C) Zero water potential
D) Negative water potential
  • 14. When pure water and a salt solution are connected with no restriction on flow, where does the water move?
A) From pure water to the solution
B) It evaporates instantly
C) From the solution to pure water
D) It does not move at all
  • 15. Until when does water flow from pure water to a salt solution continue?
A) Until all the salt is dissolved
B) Until the difference in potential is equalized or balanced by another factor
C) Until the container overflows
D) Until the temperature reaches zero
  • 16. What abiotic factor affects sapling growth because water is needed for photosynthesis?
A) Soil color
B) Rock composition
C) Soil moisture
D) Wind velocity
  • 17. Why do saplings depend on adequate soil moisture?
A) For attracting pollinators to the roots
B) For increasing soil acidity
C) For photosynthesis, nutrient transport, and maintaining turgor pressure
D) For generating heat and electrical energy
  • 18. What happens to a sapling when there is too little water?
A) Wilting and reduced growth
B) Increased oxygen absorption
C) Waterlogging and root rot
D) Accelerated flowering and oversized leaves
  • 19. What happens when too much water is present in the soil for saplings?
A) It waterlogs the soil, reducing oxygen for root respiration and slowing growth
B) It causes the plant to undergo rapid photosynthesis at night
C) It turns the soil into solid rock
D) It increases the oxygen content and speeds up growth
  • 20. What does Ψ0 represent in the total water potential equation?
A) Reference correction
B) Pressure component
C) Solute potential
D) Gravimetric component
  • 21. What does Ψπ represent in the total water potential equation?
A) Matrix effects
B) Potential due to humidity
C) Reference correction
D) Solute or osmotic potential
  • 22. What does Ψp represent in the water potential formula?
A) Gravimetric component
B) Reference correction
C) Solute potential
D) Pressure component
  • 23. What does Ψs represent in the equation for total water potential?
A) Pressure component
B) Potential due to humidity
C) Gravimetric component
D) Matrix effects
  • 24. What does Ψv represent in the water potential components?
A) Potential due to humidity
B) Solute potential
C) Gravimetric component
D) Reference correction
  • 25. What does Ψm represent in the water potential equation?
A) Reference correction
B) Potential due to matrix effects
C) Pressure component
D) Osmotic potential
  • 26. Which of the following is given as an example of matrix effects in water potential?
A) Atmospheric temperature
B) Fluid cohesion and surface tension
C) Gravitational pull
D) Dissolved mineral salts
  • 27. How are all the component factors of water potential quantified?
A) As kinetic energy per second
B) As potential energies per unit volume
C) As total mass per unit area
D) As electrical charge per mole
  • 28. What is typically defined as the reference condition in soils?
A) Frozen water at a depth of ten meters
B) Seawater at the bottom of the ocean
C) Pure water at the soil surface
D) Water vapor in the upper atmosphere
  • 29. What structural component opposes the outward pressure of water inside a plant cell?
A) The nuclear membrane
B) The vacuole
C) The chloroplast
D) The cell wall
  • 30. What is the pressure potential in plasmolysed cells?
A) Almost zero
B) Strongly negative
C) Extremely high
D) Unpredictable
  • 31. Which plant structure is associated with negative pressure potentials?
A) Stoma
B) Phloem sieve tube
C) Root hair
D) Xylem vessel
  • 32. What property of the cell wall provides the opposition to the outward pressure?
A) Chemical neutrality
B) Thermal conductivity
C) Structural rigidity
D) Elastic permeability
  • 33. Can solute potential ever be positive?
A) No
B) Yes
C) Only in pure water
D) Only at high temperatures
  • 34. Which equation gives the relationship of solute concentration to solute potential?
A) Fick's first law
B) Ideal gas law
C) van 't Hoff equation
D) Darcy's law
  • 35. What does the letter R represent in the van 't Hoff equation?
A) Relative humidity
B) Resistance rate
C) Ideal gas constant
D) Root pressure
  • 36. What does the letter T represent in the van 't Hoff equation?
A) Total time
B) Absolute temperature
C) Transpiration rate
D) Turgor pressure
  • 37. In a plant cell, the outward flow of water may eventually cause what to happen?
A) Cell division
B) Photosynthesis acceleration
C) Plasmolysis
D) Turgor pressure increase
  • 38. What is necessary for liquid water to move in response to differences in osmotic potential?
A) High atmospheric pressure
B) Stagnant soil conditions
C) A semipermeable membrane
D) Direct sunlight
  • 39. What type of intermolecular forces occur between water and solid particles like clay or sand?
A) Covalent
B) Adhesive
C) Repulsive
D) Metallic
  • 40. Adhesive forces combined with attraction among water molecules promote the formation of what structures within the solid matrix?
A) Vapor pockets
B) Ice crystals
C) Air bubbles
D) Menisci
  • 41. What magnitude factor does the matrix potential depend on regarding solid particles?
A) Volume of the air
B) Depth below sea level
C) Temperature of the solid
D) Distances between solid particles
  • 42. What is the soil state at a potential of 0 kPa?
A) Field capacity
B) Permanent wilting point
C) Saturation
D) Hygroscopic level
  • 43. What soil potential corresponds to field capacity for general soils?
A) 0 kPa
B) -100 kPa
C) -33 kPa
D) -1500 kPa
  • 44. What is the field capacity potential specifically for sand?
A) -33 kPa
B) -1500 kPa
C) -10 kPa
D) 0 kPa
  • 45. Where is water typically located when soil is at field capacity?
A) The atmosphere
B) Macropores
C) Micropores
D) Plant leaves
  • 46. Where is air typically located when soil is at field capacity?
A) Root cells
B) Micropores
C) Macropores
D) Solid particles
  • 47. Field capacity is described as the optimal condition for plant growth and what other activity?
A) Rock weathering
B) Soil erosion
C) Water evaporation
D) Microbial activity
  • 48. At what potential is the soil at its permanent wilting point?
A) -1500 kPa
B) -33 kPa
C) -10 kPa
D) 0 kPa
  • 49. What is a typical atmospheric water potential value for dry air?
A) -33 kPa
B) -100 MPa
C) 0 kPa
D) -1500 kPa
  • 50. Which instrument is limited to a range of 0 to -85 kPa?
A) Time-domain reflectometry (TDR)
B) Tensiometer
C) Neutron probe
D) Electrical resistance gypsum block
  • 51. What device has a measurement limit range of 0 to -10,000 kPa?
A) Time-domain reflectometry (TDR)
B) Tensiometer
C) Neutron probe
D) Electrical resistance gypsum block
  • 52. If special equipment is not on hand, what simple tool can estimate soil water weight percentage composition?
A) A thermometer
B) A scale
C) A barometer
D) A ruler
Created with That Quiz — where a math practice test is always one click away.