A DNA molecule is composed of the nitrogenous bases stacked inside the two backbones made up of the phosphate and sugar molecules. The nitrogenous bases form the nucleotide which when read in the triplets called codons code for specific amino acid and then form proteins.
If we say that we have to protect the DNA than it means that we have to conserve the DNA molecule. Conserving the DNA molecule means that the sequence of nucleotide which codes for specific proteins must be conserved as it is the protein molecule that is essential for survival.
The most appropiate unit of measurement fro most types of cells is CD4 counts are measured in cells per cubic millimetre = cells/mm3. A cubic millimetre (mm3) = mm3 = 1 mm x 1 mm x 1 mm.
