POINT vs. FRAMESHIFT Mutation Activity
Name:
Biology 5.0
Date:
Period:
Below is a sequence of “nitrogen bases” on an mRNA molecule. Separate the nitrogen bases into “codons” or
“reading frames” and rewrite the sentence.
THESUNWASHOTBUTTHEOLDMANDIDNOTGETHISHAT
______________________________________________________
Compare the sequence of letters below to the sequence of the letters above. How is each one different?
Separate the “nitrogen bases” into codons again and rewrite the sentences. What type of mutation has occurred?
Substitution, deletion or insertion?
A)
THESUNWASHOTBUTTHEOLDMANDIDNOTGETHISCAT
______________________________________________________
Type of mutation?
B)
THESUNWSHOTBUTTHEOLDMANDIDNOTGETHISHAT
______________________________________________________
Type of mutation?
C)
THESUNWAASHOTBUTTHEOLDMANDIDNOTGETHISHAT
______________________________________________________
Type of mutation?
1) How did the change that occurred in A affect the sentence differently than the changes that occurred in B
and C?
2) Which of the above was a substitution?
What type of substitution was it?
3) What is another name for insertion and deletion gene mutations?
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13.3 Point Mutations
Name:
5.0 Biology
Date:
Period:
Types of Mutations
Gene mutations produce a change in one gene. Point mutations produce gene mutations that involve a change in
one or more nucleotides. Point mutations also occur at only one point in the DNA sequence. The diagram below
shows an original chromosome and three possible point mutations.
Use the words in the box to add headings to the three lower parts of the diagram.
insertion
deletion
substitution
Complete the sentences. Use the terms from the box above.
1. In a(n)
, one base is changed to a different base.
2. In a(n)
, a base is inserted into the DNA sequence.
3. In a(n)
, one base is removed from the DNA sequence.
4. Which of the following can result in a frameshift mutation? Circle each correct answer.
a) deletion
b) substitution
c) insertion
5. Why is a frameshift mutation more damaging than a substitution?
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6. By what process does the cell assemble proteins based on the sequence of RNA?
7. By what process is the information in DNA transferred to a strand of RNA?
The tables below show messenger RNA codons and the amino acids they code for. Use the tables to answer the
remaining questions.
8. How many different RNA sequences specify the amino acid histidine?
9. How many different RNA sequences specify the amino acid valine?
List them:
List them:
10. What amino acid does the RNA sequence AAA specify?
11. Indicate whether or not each of the following DNA base pair substitutions would lead to a change in amino
acids sequence by writing yes or no AND explain by specifying the amino acids.
a) AAA to AAG
b) AAA to AAC
c) TGT to TGC
d) TGT to TGA
e) TGT to GGT
f) TGT to TTT
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For each DNA sequence given below, identify the type of mutations that has occurred. Then, write the
sequence of the mRNA molecule transcribed from the gen and the amino acid sequence of the polypeptide that
would be made during translations. Note the amino acids that would be different from the original strand by
marking them with an asterisk (*).
Original Sequence
DNA:
T-A-C-C-G-A-A-T-G-G-C-G-A-T-C
RNA:
Polypeptide:
Mutated DNA
Mutated DNA
T-A-C-C-G-C-A-T-G-G-C-G-A-T-C
T-A-C-G-G-A-A-T-G-G-C-G-A-T-C
Type of Mutation:
Type of Mutation:
RNA:
RNA:
Polypeptide
Polypeptide
Mutated DNA
Mutated DNA
T-A-C-C-G-T-A-A-T-G-G-C-G-A-T-C
T-A-C-C-A-A-T-G-G-C-G-A-T-C
Type of Mutation:
Type of Mutation:
RNA:
RNA:
Polypeptide
Polypeptide
Mutated DNA
Mutated DNA
T-A-C-C-G-A-A-T-G-G-C-G-C-G-T-A-T-C
T-A-C-C-G-A-A-T-C-G-C-G-A-T-C
Type of Mutation:
Type of Mutation:
RNA:
RNA:
Polypeptide
Polypeptide
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