12U3 L9 mutations

What is a mutation?

• A change in a DNA base sequence

• A change in an RNA codon sequence

• A change in an amino acid sequence

• A change in the tertiary shape of a protein

What type of mutation involves one base being exchanged for another?

• Substitution

• Deletion

• Insertion

• Frame shift

Which of the following shows a substitution mutation during replication of the sequence AAT GCC AGA?

• TTA CCG TCT

• TTA CGG TCT

• TTA CGG TC

• TTA CGG TTC T

A substitution mutation occurs on the DNA sequence AGG, changing the triplet to AGA. What effect does this have on the final protein?

• No effect, both triplets code for serine

• No effect, both triplets code for arginine

• The protein will contain arginine instead of serine

• The protein will contain serine instead of arginine

Why are substitution mutations least likely to have an effect on the final protein?

• Because different codons can encode the same amino acid

• Because different codons encode different amino acids

• Because each amino acid has its own unique codon

• Because the genetic code is universal

Which type(s) of mutations cause frame-shift?

• Deletion

• Insertion

• Substitution

• Point

What is frame-shift?

• When every codon that follows a mutation is altered

• When a single codon is altered by a mutation

• When a mutation affects the sequence of amino acids in a protein

• When a mutation affected the final tertiary structure of a protein

What is not an effect of a mis-sense mutation?

• A codon encodes a different amino acid

• A codon becomes a stop codon and does not encode an amino acid

• One or more of the bases in a codon is altered

• All subsequent codon sequences are altered (frame shift)

What is the term used to describe a substitution mutation that turns a coding sequence into a stop codon?

A substitution mutation occurs on the DNA sequence that changes the mRNA codon CCG to CGG. How can this mutation be described?

• Mis-sense

• Non-sense

• Silent