Biology 9700 · AS & A Level · Structure of nucleic acids and replication of DNA

Structure of nucleic acids and replication of DNA — practice question

The five bases in nucleic acids are called nitrogenous organic compounds. There are two categories of base. Fig. 3.1 shows how the five bases are arranged.
(a(i))[1]

State the name of the kind of base that contains U, T and C.

(a(ii))[1]

State why it is incorrect to claim that every nucleic acid has five bases.

(b)
(c)[3]

DNA strands in a DNA molecule are said to be antiparallel. Using Fig. 3.2 and Fig. 3.3, state what antiparallel means, and explain how this arrangement affects the synthesis of new strands.

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