Microbiology Bio205 Rio Salado Final 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 1 / 4
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 2 / 4
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 3 / 4
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
A A G A A C A A A U A G
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.
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