An amount taken from a natural resource—such as trees in a forest—that does not harm the future supply is called a .

sustainable yield

managed forest

diverse growth

selective cut

Study the diagram of a cell. which structure is found only in plant cells and functions in the process of photosynthesis? w x y z

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

In an experiment examining the effects tai chi on arthritis pain, callahan (2010) selected a large sample of individuals with doctor-diagnosed arthritis. half of the participants immediately began a tai chi course and the other half (the control group) waited 8 weeks before beginning. at the end of 8 weeks, the individuals who had experienced tai chi had less arthritis pain that those who had not participated in the course.