Unit 2- What is Life?

genus

taxon above the species; group of closely related species.

Kingdom

taxon below the domain in modern biological classification that consists of one or more phyla.

cell

the smallest unit of life

Cell theory

theory that states all living things are made up of cells, all life functions occur within cells, and all cells come from pre-existing cells.

multicellular

A living thing that is made of two or more cells.

stimuli

Changes to an organism's environment. Can be internal or external.

compound microscope

Light microscope that uses more than one lens to enlarge an image

Prokaryotic cells

cells that do not have a well-defined nucleus and no membrane-bound organelles

bacteria

Simple unicellular organisms

reproduction

The process by which one organism makes one or more new organisms.

protista

Unicellular and are more complex than bacteria

fungi

Unicellular and multicellular and absorb food

organism

a living thing

homeostasis

an organism's ability to maintain steady internal conditions when outside conditions change

Domains

broadest taxon in modern biological classification that is larger and more inclusive than the kingdom.

Eukaryotic cells

cell that contains a nucleus and other membrane-bound organelles.

unicellular

describes a living thing that is made of only one cell

species

group of organisms that can can mate with one another to produce fertile offspring.

plantae

multicellular and make their own food

animalia

multicellular and take in their own food

Taxonomy

science of classifying organisms.