Water Potential

Question 1

What is water potential?

Answer 1

-the tendency of water to move out of a solution

Question 2

Does a dilute solution have high or low WP?

Answer 2

-high WP

Question 3

Water potential =

Answer 3

-solute potential + pressure potential

Question 4

What is the WP of pure water?

Answer 4

-0KPa
-no solutes

Question 5

Investigating water potential

Answer 5

-effects of immersing plant tissue in solutions of different WP

Question 6

What is the method for investigating water potential in potato

Answer 6

-cut potato cylinders same length
-remove excess moisture
-record initial mass
-leave in solution for set time
-remove, dry + record length and mass

Question 7

The results from potato practical

Answer 7

-positive % change = gained water - solution had higher WP than pot

Question 8

What is the method for investigating WP using onion cells?

Answer 8

-shown when cells undergo plasmolysis
-plant in lower WP = water leaves
-V decreases
-continues to shrink (plasmolysis)
-observe using epidermal strips
-place in range of molarities of sucrose or Na chloride
-view under light microscope
-count total % undergoing plasmolysis