Whole genes and parts of genes can be extracted from chromosomes, linked to other DNA molecules to form recombinant DNA and introduced into living cells. In a process known as gene cloning, the host cell's biochemical processes are used to make many copies of the inserted gene and the protein it codes for.
In order to conduct a research you should have an dependent variable, independent variable and the control variable. so in order to study phototropism, then you should need sun light and the growth of the plant and you must have a control that why you need a dark room.
Muscle tissue is comprised of groups of muscle cells, laid out in differing organizations depending on the muscle tissue type. For skeletal muscle tissue, the muscle tissue works together to push or pull the skeleton and move the organism conciously. For smooth muscle, the muscle tissue works together to push, pull, or constrict various structures unconciously. An example of smooth muscle is the muscles involved in pushing food through the esophagus. For cardiac muscle, the muscle tissue works together to pump the entire heart in tandem.