Energy: How Organisms Make Their Livings

Energy	•	Energy in the form of food is the key to staying alive.
	•	Every living thing has to have ways to get energy.
	•	In human life, this process is called "Making a Living."


PhotoSynthesis (photo)"light" + (synthesis) "putting together"	•	Life's second great invention was to find a way to use light to make a living.
	•	Photosynthesis transforms radiant light energy into chemical energy.
	•	Photosynthesis is a way of packaging and storing energy that originated in the sun.

How do organisms make a living? Here are eight basic paths

Photosynthesis: The Green Way	Plants on land and algae in water absorb sunlight and transform it into chemical energy.
	These Producers package the sunlight energy as food we call carbohydrates.
	Producers depend on sunlight
Grazing & Browsing: A Gentle Way	Animals such as snails, deer, grasshoppers, rabbits and monkeys eat leaves, usually without killing the plants. Many others eat seeds, flowers and fruits.
	These primary consumers package the sunlight energy as a mixture of proteins and fats we call meat.
	Primary consumers depend on plants and algae.
Predation: The Carnivorous Way	Carnivorous animals such as frogs, shrews, snakes, owls, skunks, ladybird beetles and mink, kill and eat other animals.
	These secondary consumers package the sunlight energy as a mixture of proteins and fats we call meat.
	Predators depend on grazers and browsers and on other predators.
Parasititism: A Lazy Way	Parasitic plants and animals, such as mistletoe and leeches, take food from other organisms, usually without killing them, but give nothing in return.
	Parasites usually live attached to, or inside, the host organism.
	Most parasites depend on a single species they co-evolved with.
Symbiosis: The Win-Win Way	Symbiotic organisms combine to live mutually so that both partners benefit.
	Plant and animal cells originated as a symbiosis of different kinds of bacteria.
	Virtually all plants combine their roots with symbiotic fungi (mycorrhiza) to help them absorb nutrients. Also see Gas Exchange
	Symbionts depend on each other.
Detritus--Feeding: A Clean-Up Way	Detritus is organic particles left after plants or animals are partially decomposed. Earthworms and many oceanic bottom-dwelling worms are detritus feeders and play a vital role in re-cycling organisms. Soil insects, such as springtails, and fungi are detritus feeders.
Detritus--Feeding: A Clean-Up Way	Detritus-feeders depend on dead organisms, mostly plants.
Scavenging: A Necessary Way	Scavengers, such as vultures and jackals, feed on dead animals. They are carnivores who wait to feed until their prey are dead. Many carnivores are part-time scavengers.
	Scavengers prepare bodies for decomposers.
	Scavengers depend on non-microscopic dead animals.
Decomposing: The Recycling Way	Many bacteria and fungi feed on dead organisms and break them down into their chemical parts.
	Decomposers restore life-materials to the ecological nutrient cycles and prepare them for re-use.
	Decomposers depend on dead organisms of all sizes.