Answer
The model proposed by Watson and Crick consisted of phosphate and sugar groups at the exterior of the DNA helix and nitrogenous bases bonded on the interior. Pauling's DNA model cannot exist within a cell because both the phosphate and hydroxyl groups of the sugar molecule are negatively charged and they would repel each other. Also, the nonpolar bases would not be able to bond with other water molecules of the cell.
Work Step by Step
Watson and Crick proposed the double-helix model of DNA, in which the DNA molecule consists of two helically twisted strands connected by hydrogen bonds between complementary bases. Hydrogen bonds are formed between adenine and thymine and between guanine and cytosine.
