Gas Exchange

Question 1

what is diffusion?

Answer 1

diffusion is the movement of molecules from an area of high concentration to an area of low concentration, working with the concentration gradient.

Question 2

how do single-celled organisms exchange gasses sufficiently?

Answer 2

by simple diffusion through the cell membrane

Question 3

how do multicellular organisms (such as plants and animals) exchange gasses?

Answer 3

-they have exchange surfaces and organisms
-Gills are the exchange organisms in fish, lungs in humans and leaves or roots in plants

Question 4

how do these organs increase the efficiency of exchange?

Answer 4

-having a large surface area to increase the rate of transport
-a short diffusion distance for substances to move across

Question 5

what is respiration?

Answer 5

the process requiring the uptake of oxygen and the release of carbon dioxide

Question 6

describe gas exchange during respiration

Answer 6

-oxygen diffuses down the concentration gradient form a high concentration (outside the leaf) to a low concentration (inside the leaf)
-carbon dioxide diffuses down the concentration gradient from a high concentration (inside the leaf) to a low concentration (outside the leaf)

Question 7

what is photosynthesis?

Answer 7

-plant cells photosynthesize when there is enough sunlight
-the process requires the uptake of carbon dioxide and the release of oxygen