Stars form from what celestial objects ?

  Stars are born within the clouds of dust and scattered throughout most galaxies. A familiar example, a dust cloud is the Orion Nebula. Turbulence deep within these clouds gives rise to knots with sufficient mass that the gas and dust can begin to collapse under its own gravitational attraction. Stars begin their lives as clouds of dust and gas called nebulae. The gravity of a passing star or the shock wave from a nearby supernova may cause the nebula to contract. Matter in the gas cloud will begin to coalesce into a dense region called a protostar.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.