Biodiversity

common ancestor

an ancestor that two or more descendants hold in common. 

dichotomous key

a tool that allows its user to classify unknown items. When using a dichotomous key, the user observes her item, then describes its characteristics using a series of choices with two possible answers. Each choice leads the user to another step in the key, until her item is identified.

Eukaryotic

a eukaryotic cell is one which has a defined cellular nucleus surrounded by a nuclear membrane. Eukaryotic cells can be found in both single- and multi-celled organisms.

phylogenic tree

a diagram that shows the evolutionary relationships between different species that share a common ancestor

Prokaryotic

a prokaryotic cell is one which does not contain a defined nucleus. Prokaryotes are single-celled organisms, such as bacteria, who do not possess a nucleus

Taxonomy

the branch of science concerned with naming, classifying, and describing the relationships between all living things on earth

botanist

plant scientist

paleontologist

scientist who studies pre-human life

systematist

scientist who specializes in taxonomy (otherwise known as taxonomist)

taxonomy

the branch of science concerned with naming, classifying, and describing the relationships between all living things on Earth 

systematists

people who specialize in taxonomy, taxonomists

Abiotic

elements in an ecosystem that have never been alive

Biodiversity

the collection of different kinds of organisms living in a given area at a given time 

carrying capacity

the maximum number of individuals of a particular species that an ecosystem can support at a given time

direct competition

two or more species that require the same resources and need to compete for them

immigration

the movement of individuals into an area

emigration

the movement of individuals out of an area