Chapter 42: Circulation and Gas Exchange

Question 1

How does gas exchange happen?

Answer 1

By diffusion
(Passive transport)

Particles go from high pressure to low pressure

Question 2

Gas exchange is an uptake of ____ and a release of ____.

Answer 2

O2 (oxygen)

CO2 (carbon dioxide)

Question 3

What do arteries do?

Answer 3

Carry blood away from the heart

Question 4

What do veins do?

Answer 4

Carry blood towards the heart

Question 5

What are capillaries and what do they do?

Answer 5

Vessels with thin porous walls

Gas exchange

Question 6

Lungs have sacs called _______.

Answer 6

Alveoli

Question 7

What are erythrocytes?

Answer 7

Red blood cells

Question 8

What do erythrocytes do?

Answer 8

Transport oxygen using hemoglobin

Question 9

How many oxygen molecules (O2) does each hemoglobin protein hold?

Answer 9

4

Question 10

Erythrocytes contain __________ of hemoglobin molecules

Answer 10

Millions

Question 11

When an oxygen molecule is bound (attached) to hemoglobin it __________ its affinity (attraction) for oxygen.

Answer 11

increases

Question 12

When an oxygen molecule is released (detached) from hemoglobin it __________ its affinity (attraction) for oxygen.

Answer 12

lowers