2.7.1 Diffusion in Gas Exchange

Question 1

What is diffusion

Answer 1

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

Question 2

In diffusion where do Molecules move?

Answer 2

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

Question 3

Diffusion is the process by which, what occurs?

Answer 3

gas exchange occurs

Question 4

Single-celled organisms, such as amoeba, can exchange gases sufficiently by what?

Answer 4

simple diffusion through the cell membrane

Question 5

Multicellular organisms (such as plants and animals), however, have what?

Answer 5

have exchange surfaces and organ systems that maximise the exchange of materials

Question 6

In fish what are the gas exchange organ

Answer 6

Gills

Question 7

In humans what are the gas exchange organs

Answer 7

lungs in humans

Question 8

In plants what are the gas exchange organs

Answer 8

leaves or roots in plants

Question 9

These organs increase the efficiency of exchange in a number of ways, what are they?

Answer 9

1. Having a large surface area to increase the rate of transport

Question 10

animals have gas exchange surfaces that are, what?

Answer 10

that are well ventilated to maintain steep concentration gradients