D. Because experimentation includes a control group. also, independent and dependent variables are part of an experiment they arent a type of research
Answer:
True
Explanation:
Sewage contains many substances in it like suspended solids, organic and inorganic impurities, nutrients, saprotrophic and disease causing bacteria and other microbes. Hence it is said to be a complex mixture.
The protein structures can be classified into four levels, namely the primary structure, secondary structure, tertiary structure, and quaternary structure. The primary structure is the simplest of all the structures. When all the hydrogen bonds are disrupted, the secondary, tertiary and the quaternary structures gets disrupted, which leads the protein to the most simplest structural form, that is the primary structure. In this structure, the a carbon atom is bonded to hydrogen atom, carboxyl group, amino group, and an 'R' group.
The control group is the part of an experiment that does not receive the variable and is used for comparison.
