3) the experimental approach taken in current biological investigations presumes that a) simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms. b) a life force ultimately controls the activities of living organisms and this life force cannot be studied by physical or chemical methods. c) although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods. d) living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products. e) living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena.