the rule for controls is that

a. controls are only necessary if you're not doing an experiment

b. everything should remain the same between experimental groups

c. there should be only one independent variable and one dependent variable

d. the only change we make between experimental groups is to the independent variable

B. everything should remain the same between experimental groups

Explanation:

The control group, in one experiment, is characterized by individuals who will not receive the factor being tested in the experiment, but will also be evaluated at the same time points as the subjects in the intervention group. For example, if you have bean plants and want to do an experiment where you will evaluate the effectiveness of a fertilizer on bean plants, you will apply fertilizer on 9 bean plants while one plant will be maintained without fertilizing it. However all plants will be treated the same (except for fertilizer application) and will be evaluated in the same way. The fertilizer is the factor that is being tested in the experiment, the plant that did not receive it is the control group.

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.