QuestionSBA
QuestionChoice
This describes a splice-site mutation. If there is a change in introns then the mutation may not affect the phenotype. If the splice site becomes mutated there will be incorrect splicing of pre-messenger RNA therefore, an altered RNA sequence and altered protein will be produced.
10005055
e
A mutation in a splice site produces an altered RNA sequence
QuestionChoice
This describes a silent mutation. The amino acid is not altered so there is no alteration in the polypeptide composition of the protein.
10005052
b
A single base substitution which alters the genetic code but not the amino acid
QuestionChoice
This describes a nonsense mutation. The premature termination of translation produces a truncated protein which is unlikely to carry out its normal activities.
10005051
a
A termination codon is created: UAA, UAG, UGA resulting in premature termination of translation
QuestionChoice
This describes a frameshift mutation. An insertion or deletion of a nucleotide that is not a multiple of three will change each amino acid sequence downstream. A new stop codon will be formulated thus causing a shortened altered protein to be expressed.
10005054
d
An insertion or deletion of base pairs that produce a stop codon downstream
QuestionChoice
This describes a missense mutation. If the amino acid which is coded for is chemically dissimilar to the amino acid that should be there, the structure and function of the protein will be altered. If the amino acid is chemically similar there could be conservation of the biological activity of the protein.
10005053
c
A single base substitution which codes for a different amino acid
Concept
Chapter
2693
4362
Genetic concepts
Topic
156
Medical Genetics
13557
Which one of the following describes a nonsense mutation?
a