NCERT Solutions Curiosity Chapter 10 .2.2 Role of air in the preparation of food — In-text Questions

So far the chapter has established water, sunlight and chlorophyll. The one raw material still missing is a gas from the air — carbon dioxide.

The complete list of requirements for photosynthesis is therefore:

• Carbon dioxide — from the air, entering through the stomata
• Water — absorbed by the roots and carried up by the xylem
• Sunlight — the energy source
• Chlorophyll — the green pigment that captures that energy

Activity 10.4 is designed to test the fourth item on this list.

Carbon dioxide.

Air is a mixture of gases — mainly nitrogen and oxygen, with a very small amount of carbon dioxide. Of these, it is carbon dioxide that the plant uses as a raw material and builds into glucose. It enters the leaf through the tiny pores called stomata.