1.
the regions of the surface, atmosphere, and hydrosphere of the earth occupied by living organisms
2.
a fact or situation that is observed to exist or happen, especially one whose cause or explanation is in question; a remarkable person, thing, or event
5.
any change or signal in the environment that can make an organism react in some way
6.
the condition in which an organism’s internal environment is kept stable in spite of changes in the external environment
7.
a group of similar organisms that can mate with each other and produce offspring that can also mate and reproduce
8.
the process of grouping things based on their similarities
9.
the classification system in which each organism is given a unique name, two-part scientific name indicating its genus and species
10.
the scientific study of how living things are classified
11.
a tiny, nonliving particle that enters and then reproduces inside a living cell
12.
an organism that provides a source of energy or suitable environment for a parasite to live with, in, or on
13.
single-celled organisms that lack a nucleus prokaryotes
14.
A eukaryotic organism that cannot be classified as an animal, plant, or fungus
15.
a group of similar cells that perform a specific function
16.
plants a plant that has true vascular tissue for transporting materials
17.
an animal without a backbone
18.
a body structure that is composed of different kinds of tissues that work together
