The human genome is composed of the four dna nucleotides: a, t,g and c. some regions of the human genome are extremely g-c rich. other regions are relatively a-t rich. imagine that you want to compare nucleotide sequences from two regions of the genome. sixty percent of the nucleotides in the first region are g-c (30% each of guanine and cytosine) and 40% are a-t (20% each of adenine and thymine). the second region has 25% of each of the four nucleotides. a. if you choose a single nucleotide at random from each of the two regions, what is the probability that they are the same nucleotide? b. assume that nucleotides over a single strand of dna occur independently within regions and that you randomly sample a three nucleotide sequence from each of the two regions. what is the chance that these two triplets are the same?