Exam Essays | Questions and Verified
Solutions 2024/2025
Describe the differences between deletion, insertion,
substitution, and nonsense mutations. Provide an
example of each using the following piece of DNA: TAC
CAG ATA CAC TCC CCT GCT ACT. Indicate if any of the
mutations are frameshift, nonsense, or missense
mutations. – Answer - Mutations occur when a base
sequence of DNA is permanently changed (Tortora,
Funke, & Case, 2016). Mutations can either be harmful to
an organism or beneficial depending how it alters a cell
and its activity.
A deletion mutation occurs when a section of DNA is
deleted and an insertion mutation occurs when extra
base pairs are added into a new place in the DNA (Types
of mutations, 2004). An example of an insertion mutation
from the piece of DNA above would be if bases were
added, so an insertion in the chain could be CAG ATA TGG
CAC. The bases that were inserted would be the base
,sequence TGG. If this sequence were added, bases would
be paired to the DNA sequence and may even cause a
disease. An example of a deletion mutation would be,
CAG ATA CAT CCC, the base C was removed from the
sequence CAC and therefore caused the whole chain to
be changed and incorrect. These mutations of insertion
and deletion of base pairs would be characterized as
frameshift mutations because frameshift mutations occur
when one to a few nucleotide pairs are deleted or
inserted in the DNA (Tortora, Funke, & Case, 2016). A
substitution mutation occurs when one base in the DNA
sequence is replaced with a different base, when DNA
replication occurs the base pairs with another base,
however because the original base is incorrect, so is the
based pair. For example if the base T in the sequence TAC
above was substituted for a G, then the base G would be
paired with a C, and the base pair would be GC instead of
the correct pair, which would be TA. This mutation would
be characterized as a missense mutation because it
involved base substitution (Tortora, Funke, & Case, 2016).
A nonsense mutation is when an incorrect base
substitution creates a stop codon in the middle of
synthesizing a protein. This results in the protein chain
,not being fully completed and therefore, the protein
could be nonfunctional. For example, if the sequence
CAG above were being referenced, the C base would be
replaced with a U base and therefore it would result in
the sequence of UAG, which is a stop codon. This codon
would then shut down the protein synthesis and
consequently, there would be no following sequences
after it (Tortora, Funke, & Case, 2016). Recognizing the
differences between genetic mutations would be
valuable and useful knowledge to me as a Nurse. If one of
my patients had Huntington's disease for example, I
would be able to recognize that their disease resulted
from a frameshift mutation. I would know that a
frameshift mutation caused my patient's neurological
disorder, because this disease is caused by a significant
number of bases being inserted into a gene (Tortora,
Funke, & Case, 2016) With this information I could better
identify which methods of treatment would be most
beneficial to the patient.
Translate the DNA code below to the correct chain of
amino acids (protein). Make mention of each step of the
process, with explanation of what is going on (brief
, explanation of each step).
DNA code = T A C T T A C C G A G A T T C T T G T T T A T C
mRNA code =
DNA code = T A C T T A C C G A G A T T C T T G T T T A T C
mRNA code = The mRNA code is A U G A A U G G C U C U
AAGAACAAAUAG
This would be sequence because mRNA has uracil instead
of thymine for complementary base pairing
AT (at the)
GC (golf course)
AU (arizona university)
During transcription, the enzyme RNA polymerase
synthesizes a strand of RNA from one strand of double
stranded DNA, which serves as a template. Translation
begins at AUG, which is the region of DNA that is the
terminator of transcription. Translation, or protein
synthesis, is the process that is used for decoding the
language of nucleic acids and converting the information
into the language of proteins.