Mutation Essay

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There are many different types of mutations that occur within organisms, and depending on the type of mutation it can affect the gene, and proteins that the gene encodes for. When there is an expanding nucleotide repeat mutation a sequence is duplicated and repeats within the genome. This can lead to different diseases in humans, similarly, the frequency of the repeats can determine the severity and onset of the disease. For example, Huntington disease has a CAG repeating sequence. In a normal individual, they have this sequence repeat between 9-37 time, but if they Huntington's’ the sequence occurs between 37-121 time. The more that the sequence repeats the more severe the symptoms are and the earlier the onset of the disease is. Deletion …show more content…

Transposable elements are nucleotide sequences that can be added to the DNA sequence and have multiple ways of causing mutations. When inserted transposable elements can induce deletions, duplications, and even inversions. All of these mutations as explained before can change the DNA sequence which thereby changes the mRNA and proteins produced. There are two main categories of how these different mutations occur, spontaneous and induced. Spontaneous mutations can occur during replication (Tautomeric shifts) and from chemical changes (depurination and deamination). Tautomeric shifts are when a base pair does not pair with its normal complementary partner. This is seen by cytosine pairing with adenine, and guanine pairing thymine. Likewise, depurination is the loss of a purine base and deamination is the loss of an amino group from a base. These mutations are results of natural changes in the DNA structure and occur without external forces. On the other hand, induced mutations are mutations that result from environmental effects like chemicals and radiation. Depending on the environment that an organism is in these mutations may happen more or less frequently. There are three factors that impact the rate of mutations, the frequency with which a change takes place in DNA, the probability that when a change takes place it will be repaired, and the probability that a mutation will be detected. If the organism is in an environment where is exposed to radiation

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