What is comet?define it properly

A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail.

Explanation:

 a celestial object consisting of a nucleus of ice and dust and, when near the sun, a ‘tail’ of gas and dust particles pointing away from the sun.

Aerobic breathing disrupts glucose and combines disintegrated products with oxygen that generates water and carbon dioxide. The carbon dioxide is a waste of aerobic breathing because there is no demand for cells.

Cellular respiration reactants:

Glucose and oxygen.

Cellular Respiratory Products:

CO2 and water (H2O); ATP & Heat

Anaerobic breathing:  breathing occurring in the absence of oxygen that makes certain ATP still alive to cells.

Explanation:

Cellular Respiration is the mechanism that releases energy in the presence of oxygen by breaking down food molecules.

Cellular breathing = Aerobic breathing

In mitochondria, aerobic breathing takes place.

Some of the energy generated by food decomposition is stored as ATP and some as heat.

ATP is an energy storage molecule used by every cell as its source of energy.