Autotrophs and Heterotrophs
Autotrophs are "self-feeders". They require only inorganic nutrients and an outside source of energy such as the sun or chemicals to produce organic nutrients. They are sometimes called producers. Many autotrophs contain chlorophyll and carry out photosynthesis. Other autotrophs are chemosynthetic. They obtain energy by oxidizing inorganic compounds such as ammonia, nitrates, and sufides. Chemoautotrophs can be found in some caves or along deep-sea oceanic ridges where sunlight is unavailable.
Heterotrophs are "other" feeders. They are called consumers because they consume food that was generated by producers. Herbivores are organisms that graze directly on plants or algae. Carnivores feed on other animals. Omnivores are animals that feed on both plants and animals. Detritovores are organisms that feed on detritus, which is decomposing particles of organic matter. Detritovores are decomposers and they perform a valuable service because they release inorganic substances that are recycled in the ecosystem.
Heterotrophs are "other" feeders. They are called consumers because they consume food that was generated by producers. Herbivores are organisms that graze directly on plants or algae. Carnivores feed on other animals. Omnivores are animals that feed on both plants and animals. Detritovores are organisms that feed on detritus, which is decomposing particles of organic matter. Detritovores are decomposers and they perform a valuable service because they release inorganic substances that are recycled in the ecosystem.
Trophic levels, Food Chains, web and pyramids
A food chain illustrates the transfer of energy in a community. The direction of the arrow move UP the food chain from producers to consumers. Each stage is referred to as a trophic level. The first level will be the producers. The second level is the primary consumers. The third level is the secondary consumers and so on. Take time to play the food chain game linked in the resources to explore this further!
image: http://igbiologyy.blogspot.com/2014/03/107-food-chains-food-web.html
Food chains are rarely as simple as this linear example. More often, they are various interconnected paths of energy flow. For this reason, they may be represented by a food web.
image: http://ecosystems2.weebly.com/food-web.html
Energy is lost at each level of the food chain. The organism uses some energy itself and some is lost as heat to the environment. In general, only 10% of the energy at one trophic level is available to the next level. This can be illustrated in an energy pyramid or ecological pyramid.
image: http://imgkid.com/desert-energy-pyramid.shtml
banner image: http://legacy.owensboro.kctcs.edu/gcaplan/bio/Notes/BIO%20Notes%20E%20Photosynthesis.htm