Biology · Chromosomes and DNA
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Which one among the following possess a double ringed structure?
- A
Cytosine
- B
Adenine
- C
Uracil
- D
Thymine
Purines, such as adenine and guanine, have a double-ringed structure - one hexagonal pyrimidine ring and an imidazole ring. Adenine is the correct option as it belongs to purines. Cytosine, uracil, and thymine are all single-ringed pyrimidines, making them incorrect options.
Cytosine is a single-ringed pyrimidine, not double-ringed.
Adenine is a purine with a double-ringed structure, making it the correct option.
Uracil is a single-ringed pyrimidine found in RNA, not double-ringed.
Thymine is also a single-ringed pyrimidine, not double-ringed.
Tagged under Biology · Chromosomes and DNA · 2009