Researchers use a variety of techniques to learn
more about the function of a specific gene in an
organism. In one type of experiment, called a
loss-of-function experiment, the gene being
investigated is eliminated. In a gain-of-function
experiment, extra copies of the gene being
investigated are inserted. The cell process most
directly affected in both experiments is
(1) protein synthesis
(2) waste disposal
(3) transport of materials
(4) breakdown of nutrients