Answer:
4. Molecular Bases
Explanation:
DNA is made of a long sequence of smaller units strung together. There are four basic types of unit: A (Adenine), T (thymine), G (guanine) and C (cytosine). The sequence of these bases encodes instructions. some parts of your DNA or control centers for turning genes on and off, some parts have no function, and some parts have a function that are unknown at this time.