A DNA sequence of length n is a sequence of n molecules, where each molecule is represented by one of the following four letters. C G A T (a) How many DNA sequence of length n are there? (b) How many bits (0's and l's) are required to represent a DNA sequence of length n? (c) Describe how to encode a DNA sequence of length n, using the number of bits you gave in part (b). Illustrate your description with an example