Answer:
Changes in gene expression
Explanation:
it has an alternating chemical<span> phosphate and </span>sugar<span> backbone, making the 'sides' of the ladder. (Deoxyribose is the name of the </span>sugar<span> found in the backbone of DNA.) In between the two sides of this </span>sugar<span>-phosphate backbone are four nitrogenous bases: adenine (A), thymine (T), </span>cytosine<span> (C), and guanine (G).</span>
Nucleotides - they are molecules present in cells and are formed by nitrogenous bases
