What two main biological processes are responsible for the cycling of oxygen

Main biological process are photosynthesis and respiration, responsible for the cycling of oxygen.

Explanation:

The two main process are responsible for the cycling of oxygen are photosynthesis and respiration. They are interconnected with the water cycle and carbon cycle.

The oxygen is the cycle that helps to move oxygen from biosphere, lithosphere and atmosphere. How the oxygen cycle takes place:

Photosynthesis: During the day, plants take energy from the sun, Carbon-dioxide from the air and water from the to make their food in the presence of sunlight. Their food is : Glucose. Oxygen is released into the air as a by-product.

Respiration: The oxygen is released by the plants used by animals, humans and other organisms that is breathing. During respiration, organism take in oxygen and release carbon-dioxide into the air.

Repeat: This carbon-dioxide is again take up by plants for the photosynthesis.

answer; i believe that the correct answer is(d) nondisjunction during meiosis;

nucleus

would be most reasonable answer tbh