The Life Cycle of a Star and the Hertzsprung-Russel Diagram

Identify 4 biogeochemical cycles. Why is it necessary that biogeochemical cycles exist? Explain. Describe abiotic ecosystem components and include three examples. Briefly describe the events which take place in/on Earth’s Sun to release large amounts of energy. Define biome: include the two major factors which determine biome type. ................
................