4.3 Osmosis

Question 1

Define osmosis

Answer 1

the passage of water from a region where it has a higher water potential to a region where it has a lower water potential through a selectively permeable membrane

Question 2

What effect does the addition of solutes have during osmosis?

Answer 2

reduces water potential to a negative value

Question 3

during osmosis in plant cells where does the net movement of water occur to and from?

Answer 3

the vacuole

Question 4

how is water potential measured?

Answer 4

units of pressure (kpa)

Question 5

When a cell is hypotonic what is the…
solute concentration outside cell :
water potential outside cell :
net movement of water :

Answer 5

lower
higher
in to the cell

Question 6

When a cell is isotonic what is the…
solute concentration outside cell :
water potential outside cell :
net movement of water :

Answer 6

same
same
no net movement

Question 7

When a cell is hypertonic what is the…
solute concentration outside cell :
water potential outside cell :
net movement of water :

Answer 7

higher
lower
out of cell

Question 8

Under hypotonic conditions what happens if too much water enters an animal cell?

Answer 8

Lysis (The cell may burst)

Question 9

in a hypertonic environment what happens if to much water leaves the animal cell?

Answer 9

The cell shrivels (crenation)

Question 10

define water potential

Answer 10

the pressure created by water molecules
it is the measure of the extent to which a solution gives out water
the greater the number of water molecules present, the higher (less negative) the water potential.
pure water has a water potential of zero