Answer:
1. The bases are on the <u>interior</u> of the double helix.
2. They are arranged<u> neatly stacked</u>.
3. The phosphate groups are on the <u>exterior</u> of the DNA molecule.
4. The sugar groups on the <u>exterior</u> of the DNA molecule.
Explanation:
DNA is made up of basic chemical components called nucleotides. These basic components include a phosphate group, a sugar group and one of four types of alternative nitrogenous bases. To form a strand of DNA, the nucleotides unite to form chains, alternating with the phosphate and sugar groups.
The four types of nitrogenous bases found in nucleotides are: adenine (A), thymine (T), guanine (G), and cytosine (C). The order, or sequence, of these bases determines which biological instructions are contained in a strand of DNA, being within the strands already mentioned.