A __________ can be described as an area with a particular combination of physical and biological environmental factors that affect which organisms can live within it.

Even your mouth, gut, and skin are home to _{____________} whose inhabitants outnumber your own cells and powerfully influence your health!

Every species has its own range of ____________, the variety of environmental conditions within which it can survive and reproduce.

If one or more environmental conditions, such as temperature, rise above or fall below that optimum range, then individuals experience ____________.

Organisms under stress must expend more energy to maintain ________, and that leaves less energy for growth and reproduction.

A __________  describes where an organism lives and what it does "for a living,"

A species' niche includes the range of physical and biological conditions in which it can survive and reproduce, as well as the way it obtains _____________ it needs.

Wh When more than one organism attempts to use the same limited ecological resource in the same place at the same time, _________________ occurs.

Direct competition between species almost always produces a winner and: loser--and the losing species ___________.

By causing species to divide____________, competition helps determine the numbers and kinds of species in a community and the niche each species occupies.

_____________ affect the size and distribution of plant populations in a community, and determine the places that certain plants can survive and grow.

 ____________ plays a vital and unique role in maintaining structure, stability, and diversity in an ecosystem.

A particularly close, interdependent relationship between two species is called ___________.

A relationship in which one organism be and the other is neither helped nor harmed is called _____________.

A relationship between two species in which both species benefit is called______________.