Breathing is a crucial activity for living organisms, allowing for gas exchange with the environment. Humans breathe to intake oxygen and expel carbon dioxide, a waste product. This exchange primarily occurs in the lungs, where oxygen is absorbed into the blood, and carbon dioxide is released. The heart is essential in this process, pumping oxygen-depleted blood to the lungs and distributing oxygen-rich blood throughout the body.

How many times do humans typically breathe per minute?

• 30 times

• 10 times

• 18 times

• 25 times

What is the primary reason humans need to breathe?

• To produce energy

• To regulate body temperature

• To exchange gases with the environment

• To cool down the body

What waste product is expelled from the body during exhalation?

• Oxygen

• Nitrogen

• Carbon dioxide

• Hydrogen

Where does the major exchange of gases occur in the human body?

• Heart

• Liver

• Kidneys

• Lungs

What role does the heart play in the process of gas exchange?

• It pumps oxygen-depleted blood to the lungs

• It stores oxygen

• It filters the blood

• It produces carbon dioxide