HORTICULTURE

Detailed explanation-1: -Through a process called photosynthesis, leaves pull in carbon dioxide and water and use the energy of the sun to convert this into chemical compounds such as sugars that feed the tree. But as a by-product of that chemical reaction oxygen is produced and released by the tree.

Detailed explanation-2: -In photosynthesis, water, carbon dioxide, and energy in the form of sunlight are inputs, and the outputs are glucose and oxygen.

Detailed explanation-3: -Oxygen is produced by photosynthesizing organisms that live in the ocean, in fresh water, and on land. These organisms include bacteria, algae and plants. Photosynthesizing algae in the ocean produce around 70% of oxygen in the atmosphere.