Question

what would happen to the planet if all oxygen breathing organisms became extinct and only plants remained on the earth

Answer 1

see plants are also living beings, they also need oxygen for respiration. There would be less carbon dioxide available for plants for photosynthesis. Atmosphere will be clean, less polluted, clean water. No fighting, peaceful, cool environment

Answer 2

Answer: There will an increase in the concentration of oxygen in the environment.

Explanation:

If there will be an increase in the oxygen concentration on the planet. The increase in the oxygen concentration because of which there will be an oxidizing environment on earth.

There will be more and more oxygen in the environment and plants can only take carbon dioxide and release oxygen in the environment so oxygen will be in increasing concentration.