diffusion

Question 1

what is diffusion?

Answer 1

the net movement of particles from an area of high concentration to low concentration down to a concentration gradient.

Question 2

what main factors affect diffusion?

Answer 2

concentration gradient- larger gradient, faster diffusion.
temperature- higher temperature, faster diffusion.
surface area- larger surface area , faster diffusion

Question 3

give examples of substances transported by diffusion into the lungs and kidney?

Answer 3

lungs- oxygen diffuses into the blood into the lungs and carbon dioxide diffuses into the lungs from the blood.
kidney- urea diffuses from the cells into the blood plasma.

Question 4

how are single-celled organisms adapted for diffusion

Answer 4

large surface area to volume ration. maximising the rate of diffusion of molecules to meet the organisms needs