Describe the three general methods used by ecologists to study organisms

  1) observation in situ: going out into the field and studying the organisms as they go about their daily business in their natural habitat. 
2) observation in the lab, or in an altered or limited habitat 
3) experimentation - either in its natural habitat, or in an artificial or limited one. 
4) by studying a habitat where the organism has been eliminated from, to see what happens without it. 
5) by examining dead specimens: analyzing tissue composition, stomach contents, scars & health problems which can only be determined after death, etc. 
1 and 2 can be combined into "observation".

Answer is c just took the test on edgenuity