An atom consists of an atomic nucleus composed of positively charged protons and neutral or uncharged neutrons.
Animals release carbon dioxide (CO2) into the atmosphere through the process of respiration.
Explanation:
I'm guessing the answer is oxygen.
The kingdom described above is the kingdom Animalia. Heterotrophic mode of nutrition is a type of nutrition in which organisms depends upon other organisms such as plants for survival, for example all animals are heterotrophic and obtain all organic materials they need to survive. The other type of nutrition is the autotrophic mode of nutrition in which organisms use simple inorganic substances to synthesize organic molecules, a characteristic of plants.
