Sugar , phosphate , and one of the 4 bases (adenine ,guanine,cytosine,thymine)
The structure of the lipid bilayer allows small, uncharged substances such as oxygen and carbon dioxide, and hydrophobic molecules such as lipids, to pass through the cell membrane, down their concentration gradient, by simple diffusion.
A GWAS can be performed by actually genotyping as few as 300000 to 1million
