Movement of Gases Across the Membrane

What is the primary function of the respiratory system?

• To control body temperature

• To circulate blood throughout the body

• To exchange gases like oxygen and carbon dioxide

• To support the digestive system

Where does the exchange of gases occur within the lungs?

• In the trachea

• In the nasal cavity

• In the bronchi

• In the alveoli

What is diffusion in the context of respiratory gas exchange?

• The filtering of gases through a solid barrier

• The active transport of gases using energy

• The movement of gases from an area of lower to higher concentration

• The movement of gases from an area of higher to lower concentration

Why does the smell of baking biscuits spread throughout a house?

• Because of the heat from the oven

• Because of the movement of air currents

• Because of diffusion

• Because of moisture in the air

Which example illustrates diffusion outside the human body?

• Blood flowing through veins

• Water being absorbed by roots

• Oxygen entering muscle cells

• Helium escaping from a balloon

Gases (such as carbon dioxide and oxygen) can diffuse through the lipid membrane because they are

• small and nonpolar

• small and polar

• compatible with protein channels that permit their passage