(i) A DNA segment has a total of 1000 nucleotides, out of which 240 of them are adenine containing nucleotides. How many pyrimidine bases this DNA segment possesses?

Since, the number of adenine (A) is equal to the number of thymine (T) and A = 240 (given)

Therefore, T = 240

Also, the number of guanine (G) is equal to cytosine ©. Thus, G + C = 1000 - (A + T)

G + C = 1000-480 = 520 Hence, G = 260, C = 260

The number of pyrimidine bases, i.e. C + T (2)

= 240 + 260 = 500