B3.1.1

What is gas exchange?

A process by which multicellular organisms take in gases they need from their environment and release gases that are waste products of metabolism

What gases are exchanged during gas exchange?

Oxygen (needed for metabolism) and CO2 (a waste product of metabolism)

Where does gas exchange occur in mammals?

The alveoli of the lungs

What is the role of diffusion in gas exchange?

Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

How does oxygen move during gas exchange?

Oxygen diffuses from areas where it's abundant, such as the external environment, into the blood capillaries where it is less concentrated.

How does carbon dioxide move during gas exchange?

Carbon dioxide moves from areas of higher concentration in the blood to areas of lower concentration in the alveoli.

What problem do larger organisms face regarding gas exchange?

Larger organisms face the problem that their volume increases faster than their surface area, making it difficult to exchange gases efficiently.

Why do larger organisms need specialized structures for gas exchange?

Larger organisms need specialized structures to maintain a large enough surface area for efficient gas exchange.

What happens to carbon dioxide during gas exchange

Carbon dioxide is released from the blood into the alveoli to be exhaled.

How do smaller organisms perform gas exchange?

Smaller organisms can perform gas exchange directly across their surface due to their small size and relatively large surface area compared to their volume.