Detritovore

A detritovore is an organism that feeds on and breaks down dead plant or animal matter, returning essential nutrients to the ecosystem. This worm I found in my garden is an example of a detritovore. They live in soil and decompose organic matter to survive.

introduced species

A species that does not occur naturally in a given area is an introduced species. These are non-native species that were somehow introduced to this new area. This tree in my backyard (we think it's an Austrian blue spruce) is an introduced species. It is not native to Montana.

Glycogen

Glycogen is a substance deposited in body tissues. It's the main form of carbohydrate storage in animals, and is converted to glucose as needed. Glycogen is found in human muscles, like the ones demonstrated by my sister. 

Predation

Predation is the capturing of prey as a means of maintaining life. A spider (the predator) living in this spiderweb captures flies and other insects (the prey) in its web and then consumes them in order to survive.

homologous structures

Homologous structures are body parts that are alike because the species share a common ancestor.  Unlike analogous structures, meaning that it preforms the same function, homologous structures don't necessarily preform the same function; they just share a common ancestral origin. As an example, I have a bird's wing, which is homologous to the human arm. They have the same basic skeletal structure, and are derived from the same origin, but they are used differently.