Movement in and out of cells

Question 1

Define diffusion

Answer 1

Diffusion is the movement of molecules from a region of its higher concentration to a region of its lower concentration.

Molecules move down a concentration gradient, as a result of their random movement

Question 2

What does diffusion help organisms do?

Answer 2

Diffusion helps living organisms to:

• obtain many of their requirements
• get rid of many of their waste products
• carry out gas exchange for respiration

Question 3

What are the 3 factors that affect the rate of diffusion?

Answer 3

• Distance
• Temperature
• Concentration gradient

(In depth explanation in notes and textbook)

Question 4

Define Osmosis

Answer 4

Osmosis is the diffusion of water molecules from a dilute solution (high concentration of water) to a more concentrated solution (low concentration of water) across a partially permeable membrane

Question 5

Define Active Transport

Answer 5

Active transport is the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration.