The subunits are called nucleotides
A virus is bacterial. It has cells but it isn’t a living thing so to speak.
An organism is a number of tissues (organs) working together. It has a conciseness, and also has cells.
I believe it is the "myelin sheath." White matter = myelinated (has myelin sheath), while gray matter = unmyelinated (no myelin sheath)!
<em>Deoxyribonucleic Acid</em>
