(a) If the haploid human genome contains 3 × 109 nucleotide pairs and the average molecular weight of a nucleotide pair is 660, how many copies of the human genome are present, on average, in 1 mg of human DNA? 

(b) What is the weight of one copy of the human genome?

(c) If the haploid genome of the small plant Arabidopsis thaliana contains 7.7 × 107 nucleotide pairs, how many copies of the A. thaliana genome are present, on average, in 1 mg of A. thaliana DNA? 

(d) What is the weight of one copy of the A. thaliana genome? 

(e) Of what importance are calculations of the above type to geneticists?