Question

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9. The nitrogen base which is characterised as a
substituted purine is
(1) Cephalin
(2) Cytosine AT
(3) Thymine
(4) Adenine​

Answer 1

hey dude

here's your answer

Answer:

adenine

if you got your answer then you can mark it as a brain list:-)

Answer 2

Answer:

The nitrogen base which is characterised as a  substituted purine is Adenine

Option D

Explanation:

Adenine and guanine are the purine nitrogen bases with purine ring structures. This adenine when joins with a ribose sugar forms the Adenosine. Adenosine when joins with a phosphate form adenylic acid. This adenylic acid or Adenosine monophosphate (AMP).

These adenine pairs with the thymine of the parallel structure of the other strand of the DNA utilizing three hydrogen bonds. Guanine pairs with cytosine of the other strand utilizing 2 hydrogen bonds.