Answer:
Biosphere
Explanation:
The biosphere is the part of the earth that supports life forms. It includes hydrosphere, atmosphere, and lithosphere. Various ecosystems, aquatic or terrestrial, are present in the biosphere. Biotic and abiotic components of a geographical region that interact with each other together make an ecosystem.
The biotic component of an ecosystem includes all the organisms present in it. Organisms may be unicellular or multicellular. All the organisms are made up of one or more cells. Cells are made up of various biomolecules that interact and enable cells to perform the life processes.
The producers at the beginning of the Earth's food chain are plants.
Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide in the process of respiration, which is then used in photosynthesis. While water is broken down to form oxygen in photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water. ATP is manufactured as a result of several processes including fermentation, respiration and photosynthesis.
1. gamete production
2. sperm transported near egg
3. fertilization
4. zygote forms