The Reintroduction of Wolves into Yellowstone in 1995 Had _______

question 72

Multiple Choice

The reintroduction of wolves into Yellowstone in 1995 had _______ effect on aspen and _______ effect on elk.

• A) a direct; a direct
• B) a direct; an indirect
• C) a direct; no
• D) an indirect; a direct
• E) an indirect; an indirect

---

Definitions:

Control Group

In experimental research, a group of subjects that does not receive the experimental treatment and is used as a benchmark to measure the effects of the treatment.

Sugar Pills

Placebo tablets made of inert ingredients, used in medical trials to examine the effect of treatments without drug involvement.

ADHD

Attention Deficit Hyperactivity Disorder, a behavioral condition characterized by inattention, hyperactivity, and impulsivity.

Independent Variables

Factors in an experimental study that are manipulated or changed to determine their effect on dependent variables.