Question

84. How do plants and animals help each other in the exchange of gases in the atmosphere?

Answer 1

• Plants make their food using Carbon dioxide $\left({\mathrm{CO}}_2\right)$, water $\left({\mathrm{H}}_2\mathrm{O}\right)$ and sunlight, thus producing carbohydrates (sugar) and releasing Oxygen $\left({\mathrm{O}}_2\right)$ in a process known as photosynthesis.
• The Carbon dioxide needed for photosynthesis is directly absorbed from the air using leaves.
• Animals breathe air into their lungs, where all the blood vessels take in fresh oxygen and release Carbon dioxide. This Carbon dioxide is then exhaled through the nostrils. This process is called respiration.

Thus, plants and animals help each other in the exchange of gases in the atmosphere using photosynthesis and respiration respectively.