Understanding Fish Respiration

Why can't humans breathe underwater like fish?

• Humans have smaller lungs than fish.

• Water contains insufficient oxygen for human lungs.

• Fish have special cells that don't need oxygen.

• Humans can breathe underwater with practice.

What percentage of oxygen is present in the air we breathe?

• 78%

• 21%

• 85%

• 1%

How do fish manage to survive in water with less than 1% oxygen?

• Fish need less oxygen than humans.

• Fish don't need oxygen to survive.

• Fish have gills that efficiently extract oxygen.

• Fish have lungs similar to humans.

What is the efficiency of fish gills in extracting oxygen from water?

• 25%

• 50%

• 85%

• 100%

Why can't fish breathe outside of water?

• They are not used to breathing air.

• They need more oxygen than air provides.

• They don't have lungs.

• Their gills need to be wet to function.