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 segment of a eukaryotic gene that is not represented in the mature messenger RNA is known as: 
Select and explain. 
A. Intron, B. Exon, C. Plasmid, D. TATA box
A: Intron
Answer: A: Intron 
Explanation: A i.e. Intron