Describes how efficiency of cellular respiration and production of carbohydrates through photosynthesis as well as oxygen has benefitted society. explain how the earth would appear if endosymbiosis hadn’t occurred.

Cellular respiration is the process by which cells convert glucose into energy in the form of ATP. The process of aerobic respiration produces huge amount of ATP from each sugar molecule. Aerobic respiration takes place  in eukaryotes.   The reactions involved in the respiration are catabolic reactions. From the complete oxidation of one glucose molecule to carbon dioxide and oxidation of all reduced coenzymes. It  generates 30-32 ATP in each cycle and used by plants, animals and humans therefore  it is highly efficient and beneficial for the society. Without photosynthesis plants will not have carbohydrates for respiration.  

Endosymbiosis is the hypothesis which says that prokaryotes gave rise to the first eukaryotic cell. It explains the origin of eukaryotic cell organelles such as mitochondria in animals and fungi and chloroplast in plants have evolved from prokaryotes like mitochondria has evolved from proteobacteria and chloroplast from cynobacteria. It simply defines that primitive simple organisms evolved in order to develop as  complex organisms. If endosymbiosis had not occurred on earth than there would be no diversity in life forms on earth.

igneous rocks which formed by the crystallization of magma at the surface of the earth called extrusive rocks. they are characterized by fine-grained textures because the rapid cooling at or near the surface did not provide enough time for large crystals to grow.