movement in and out of cells

Question 1

define diffusion

Answer 1

net movement of molecules from a region of higher concentration to a region of lower concentration until evenly distributed

Question 2

diffusion in plants

Answer 2

• movement of CO2 into leaf and into chloroplasts
• movement of O2 and water vapour out of the cell
  (loss of water vapour here is transpiration)

Question 3

diffusion in animals

Answer 3

• movement of oxygen into the blood
• movement of carbon dioxide into blood

Question 4

factors affecting rate of diffusion

Answer 4

• temperature
• steepness of concentration gradient
• distance to be travelled
• surface area

Question 5

define osmosis

Answer 5

net movement of water molecules form a region of high water potential to a region of lower water potential through a partially permeable membrane

Question 6

plant cell in dilute solution

Answer 6

turgid

Question 7

plant cell in low water potential solution

Answer 7

flaccid

Question 8

plant cell in concentrated solution

Answer 8

plasmolysed

Question 9

animal cell in low water potential

Answer 9

crenated

Question 10

animal cell in high water potential

Answer 10

burst

Question 11

importance of osmosis in water uptake

Answer 11

• ## water enters root hair cells by osmosis

Question 12

plants are supported by

Answer 12

turgor pressure when vacuoles increase in volume

Question 13

define active transport

Answer 13

movement of particles from a region of high to low concentration through a partially permeable membrane using energy from respiration

Question 14

how active transport works

Answer 14

energy is used to open part of carrier protein (embedded into membrane) that faces outward, molecule binds to this site, energy used to close opening and inward channel is opened releasing the molecule into cytoplasm