Summary of Chapter

Producer/Autotroph: An organism which makes its own food and synthesizes its own energy by one of two processes (listed below). Producers are preyed on by primary consumers. (Auto meaning self, and troph meaning energy/nourishment)

Photoautotroph: Producers which perform the chemical reaction of photosynthesis (converting the sun's energy and carbon dioxide into breathable oxygen, water and glucose (which it uses for food/energy). Plants and blue-green algae (cyanobacteria) are photoautotrophs.

Chemoautotroph: Producers which convert inorganic chemical compounds into organic ones, getting energy from chemical reactions and gain organic compounds from carbon dioxide. Certain bacteria species are chemoautotrophs. They often live in extremely hostile places such as deep sea vents.

https://en.wikipedia.org/wiki/Chemotroph#Chemoautotroph

Consumer/Heterotroph: Organisms which can't create their own energy, and thus must eat either producers, other consumers, or both. Are classified as herbivores, omnivores, and carnivores.

Primary Consumer: An organism which doesn't eat other consumers, and only eats producers. Is preyed upon by secondary consumers, which are in turn preyed upon by tertiary consumers, which are preyed on by quaternary consumers.

Note: in a food web, an organism which is one level of consumer, can simultaneously be another level of consumer as well.

For example.

One path could be: Grass -> Mouse -> Snake -> Hawk (Mouse is primary consumer)

and another path could be: Grass -> Grasshopper -> Mouse -> Snake -> Hawk (Mouse is secondary consumer which bumps up snake and hawk to the levels above)

Carnivore: A species which mainly or fully eats other consumers. Not to be confused with omnivores which eat both other consumers, and producers as well.

Hypocarnivore: 50% or less of their diet consists of meat. Sometimes grouped into the omnivore category. Examples include: the grizzly bear, the brown bear, and the kinkajou.

Mesocarnivore: 50 - 70% of their diet consists of meat. The rest consists of non-vertebrate animals including insects, as well as plant matter or fungi. Examples include: The red fox, the raccoon, and the mongoose

Hypercarnivore: More than 70% of their diet consists of meat. The rest consists of plant matter or fungi. Examples include: the lion, the polar bear, and the tiger.

Decomposer: Organisms which break down detritus for their own nourishment, thus allowing the nutrients locked in the detritus to be accessed by producers, thus re-starting the nutrient cycle. Examples of decomposers include many bacteria and fungi species, as well as some animals such as earthworms.

1. Energy (and matter) cannot be created or destroyed, only cycled between forms). Because in nature things always cycle.