Any organism requires energy to function and the energy can be transferred from one kind to a different kind of organism mostly by consumption. A plant can transform light energy into chemical energy; an animal can transform chemical energy into energy of movement by the muscles and can transform energy of movement into heat, and so on. The Sun is the main source of energy on Earth. Primary producers or autotrophs like Phytoplankton and Algae synthesize organic materials. The synthesis of organic materials from inorganic substances by photosynthesis or chemosynthesis is called primary productivity. Primary producers use CO2 as carbon source and sunlight as energy to produce glucose. Primary, secondary and top consumers in a trophic food web consume organisms from primary producers level to a top level consumer accordingly, where top level consumer are the most severe predators. A food web represents groups of organisms “linked by complex feeding relations in which the flow of energy can be followed from primary producers through consumers.” Catastrophic events on Earth such as collisions of the Earth with asteroids can cause extinctions of many organisms. Catastrophic events happened to be at least six times in the last 450 million
Any organism requires energy to function and the energy can be transferred from one kind to a different kind of organism mostly by consumption. A plant can transform light energy into chemical energy; an animal can transform chemical energy into energy of movement by the muscles and can transform energy of movement into heat, and so on. The Sun is the main source of energy on Earth. Primary producers or autotrophs like Phytoplankton and Algae synthesize organic materials. The synthesis of organic materials from inorganic substances by photosynthesis or chemosynthesis is called primary productivity. Primary producers use CO2 as carbon source and sunlight as energy to produce glucose. Primary, secondary and top consumers in a trophic food web consume organisms from primary producers level to a top level consumer accordingly, where top level consumer are the most severe predators. A food web represents groups of organisms “linked by complex feeding relations in which the flow of energy can be followed from primary producers through consumers.” Catastrophic events on Earth such as collisions of the Earth with asteroids can cause extinctions of many organisms. Catastrophic events happened to be at least six times in the last 450 million