This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
A codon in the genetic code consists of: 
Select and explain. 
A. One molecule of charged-tRNA, B. A Shine-Dalgarno sequence, C. Three consecutive nucleotides, D. Two complementary base pairs
C: Three consecutive nucleotides
Answer: C: Three consecutive nucleotides 
Explanation: A codon is a triplet sequence of bases. The tRNA molecule contains an anticodon. The Shine-Dalgarno sequence is found in the 23S prokaryotic ribosomal RNA. A codon is on the same strand of DNA or mRNA.