Concept:Ecological investigation studies organisms in relation to their environment, not their internal genetic details.Explanation:In an ecological investigation, a habitat is first chosen for study.The organisms found there are identified and recorded.Both abiotic factors (like temperature and rainfall) and biotic factors (like predators and food) are measured.Determining the genetic makeup of specimens is a laboratory or genetics procedure.It is not a standard ecological field procedure.Answer:C. determining the genetic makeup of specimens