NEET BIOLOGY

Detailed explanation-1: -The major source of oxygen on Earth is biological production by the autotrophic organisms. Complete answer: Oxygen is returned to the atmosphere mainly by photosynthesis which is done by photosynthetic autotrophic organisms like green plants. This is a part of the oxygen cycle of the Earth.

Detailed explanation-2: -Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth’s atmosphere, and supplies most of the energy necessary for life on Earth.

Detailed explanation-3: -Photosynthesis provides most of the oxygen that humans and animals breathe. Here’s how it works: Tree and plant roots absorb water, as well as minerals and nutrients, from the soil. At the same time, the leaves or needles absorb carbon dioxide from the air.

Detailed explanation-4: -Oxygen Supply Half of the world’s oxygen is produced via phytoplankton photosynthesis. The other half is produced via photosynthesis on land by trees, shrubs, grasses, and other plants. As green plants die and fall to the ground or sink to the ocean floor, a small fraction of their organic carbon is buried.

Detailed explanation-5: -Explanation: Oxygen is not required for the process of photosynthesis. Carbon dioxide is required for the process of photosynthesis. Oxygen is given out during the process of photosynthesis.