Nucleotides are the basic building blocks that make up DNA, consisting of a deoxyribose sugar, phosphate group, and nitrogenous base. The main difference between the four nucleotides is the nitrogenous base, Adenine, Thymine, Guanine, or Cytosine. Adenine pairs with Thymine, and Guanine pairs with Cytosine. The order in which these pairs come in code for proteins and hold genetic information.
<em>The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it pumps blood against a greater resistance. -C.</em>
