transport in cells (4.1.3)

Question 1

definition of diffusion

Answer 1

movement of particles in a substance from a high concentration to a low concentration until they are at equilibrium.

Question 2

3 factors which affect diffusion

Answer 2

• concentration gradient
• temperature
• surface area of membrane

Question 3

adaptations for effective diffusion

Answer 3

• large surface area
• thin membrane
• efficient blood supply
• being ventilated

Question 4

definition of osmosis

Answer 4

the diffusion of water from a dilute region to a concentrated region via a partially permeable membrane.

Question 5

definition of active transport

Answer 5

movement of particles against the concentration gradient from a low concentration to a high concentration via a semi permeable membrane using energy (from respiration)

Question 6

examples of exchange surfaces

Answer 6

alveoli
villi
root hair cell

Question 7

what is the function of alveoli

Answer 7

in the lungs for gas exchange

Question 8

what is the function of the villi

Answer 8

in small intestine for absorption of nutrients

blood vessels near by

Question 9

function of root hair cell

Answer 9

in roots of plants for absorption of minerals and water

large surface area

Question 10

features of exchange surfaces

Answer 10

• thin / short diffusion pathways
• large surface area
• high concentration gradient