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: Pathology
The term ‘sequence’ in genetics means: 
Select and explain. 
A. Order of nucleotides within DNA, B. Order of aminoacids in tRNA, C. None, D. None
A: Order of nucleotides within DNA
Answer: A: Order of nucleotides within DNA 
Explanation: Explanation:
What is Sequence?
A nucleic acid sequence is a succession of letters that indicate the order of nucleotides within a DNA
(using GACT) or RNA (GACU) molecule.
By convention, sequences are usually presented from the 5' end to the 3' end. Because nucleic acids are normally linear (unbranched) polymers, specifying the sequence is equivalent to defining the covalent structure of the entire molecule.
For this reason, the nucleic acid sequence is also termed the primary structure.