Question

The chapter "Air and the Respiratory System" has question no. 1 on page no. 7. Explain/Solve.

Answer 1

	Lung Model	Human Respiratory System
Similarity	Balloon A inflates on pulling down balloon B.	When we breathe in, the thin sheet of muscle moves down and the lungs are filled with air.
	Balloon A deflates on releasing balloon B.	When we breathe out, the thin sheet of muscle moves up and the air rushes out of the lungs.
Difference	The lung model is prepared using plastic cups, plasticine and balloons. All the parts of the respiratory system are not shown.	In reality, the respiratory system in our body consists of nostrils, windpipe, lungs and air sacs.
	Only one lung is shown.	There is a pair of lungs containing small air sacs where the exchange of gases occurs.