movement of substances in and out of cells

Question 1

explain the effect of increasing the concentration of salt solution on germination (4)

Answer 1

• less germination takes place
• less water absorbed
• by osmosis
• lower osmotic gradient

Question 2

explain the factors that affect the rate of movement of substances in and out of cells (5)

Answer 2

• the higher the temperature particles have more kinetic energy
• concentration gradient increases rate of movement
• shorter distance increases diffusion
• SA:VOL ratio increases diffusion
• mass of particles, smaller particles move faster

Question 3

describe the differences between diffusion and active transport (4)

Answer 3

• difffusion is a passive process
• active transport requires energy
• diffusion is the movement of particles from an area of high to low concentration
• diffusion can take place in non-living systems