Answer:
In an experiment, the researcher needs to have a control group with an experimental group where both groups are identical in every way except that the controlled group does not gets the experimental treatment.
Sometimes, it is not possible to do a test or the experiment utilizing a controlled trial (due to ethical reasons or no practical method available). All things considered, a researcher may test a theory by making predictions about outcomes or patterns that ought to be found in nature if the hypothesis is right.
Answer:
D. cell is the smallest part of an organism.
as cell is basic functional and structure of life.
