Mutations Practice Problems – remembe

Land – Biology
Name: _____Key______________________________
Date: ____________
Period: _______
Mutations Practice Problems – remember to use the codon chart you put in your notebook.
1. Look at the following sequence: THE FAT CAT ATE THE RAT. Delete the first H and regroup the letters
in groups of three - write out the new groups of three. Does the sentence still make sense? What type of
mutation is this an example of?
TEF ATC ATA TET HER AT
Deletion
2. Given the following three mRNA sequences, 2 code for the same protein. Which two? SHOW YOUR
WORK.
a. AGU UUA GCA ACG AGA UCA
SER- LEU - ALA – THR – ARG - SER
b. UCG CUA GCG ACC AGU UCA
SER – LEU – ALA – THR – SER – SER
c. AGC CUC GCC ACU CGU AGU
SER – LEU – ALA – THR – ARG- SER
3. Below is the base sequence for the normal protein for normal hemoglobin and the base sequence for sickle
cell hemoglobin.
Normal: GGG CTT CTT TTT
Sickle: GGG CAT CTT TTT
a. Transcribe and translate the normal and sickle cell DNA.
NORMAL
Sickle
mRNA – CCC GAA GAA AAA
mRNA – CCC GUA GAA AAA
A.A - PRO – GLU – GLU – LYS
A.A. - PRO – VAL – GLU - LYS
b. Identify this as a point or frameshift mutation. Explain your answer.
It is a point mutation because it only affects one nucleotide base. A base has not been deleted or inserted
therefore it cannot be a frameshift mutation.
c. If the base sequence read GGG CTT CTT AAA instead, would this result in sickle cell
hemoglobin? Explain.
mRNA CCC GAA GAA UUU
A.A. – PRO – GLU – GLU - PHE
No this would not be sickcle cell hemoglobin because to have sickle cell, the second amino acid has to be
changed from GLU to VAL and in this case the 2nd amino acid was not changed.
The first box contains a copy of a normal DNA sequence. Transcribe it into mRNA and then translate it into the
Amino acids.
For boxes 2 through 4, transcribe each of the mutated DNA sequences into mRNA, translate it into amino acids
and identify the type of mutation that has occurred.
1
AUG U G G AAC C G C U G C UG A
Start -
TRP - ASN - ARG - CYS - STOP
AUG U GA G AAC C G C U G C UG A
2
Start - STOP
Premature stop – non function protein
Substitution
AUG CUGGAA CCG CUG CUGA
3
Start - LEU - GLU - PRO - LEU - LEU
Incorrect amino acid sequence leads to an incorrect.non functional protein
Insertion mutation
4
AU G U G G A A U C G C U G C U G A
Start- TRP - ASN - ARG - CYS - STOP
There will be no change in the protein
Insertion – silent mutation

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