This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
In the following partial sequence of mRNA, a mutation of the template DNA results in a change in codon 91 to UAA. The type of mutation is:888990GUCGACCAG 9192UAGGGC9394UAACCG 
Select and explain. 
A. Missene, B. Silent, C. Nonsense, D. Frame shit
B: Silent
Answer: B: Silent 
Explanation: Ans. B. SilentMutations are permanent changes in DNA sequence. When mutation occur at a single base, are called as point mutations. When no detectable defect is there -Silent mutation, occurs due to degeneracy of Genetic Code. When a different amino acid is incorporated into a protein-- Missense mutation. When a terminating or stop codon is there-- Nonsense mutation. Frame shift mutation occurs when insertion or deletion of nucleotide from coding strand results in altered reading frame in mRNA.