deletion and insertion - deletion and insertion small i.e....

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deletion and insertion small i.e. less than 10kb Deletions or expansions of a small number of nucleotides happen from time to time. Some deletions are entirely random but many are caused by misalignment of short repeats during DNA synthesis, so called replication slippage . As much as 25% of the human genome is composed of repetitive DNA. Much of this is concentrated at chromosome centromes and in heterochromatic regions but a great deal of it is in the form of interspersed repetitive DNA . There are several different types of this but the two principal types are alu elements and L1 repeat elements. These interspersed repeats are very important from an evolutionary point of view. Working elements can transpose, via an RNA intermediate. New copies of the element can be inserted at random into the host genome. Sometimes, if the insertion takes place within an exon or within a control region, this can cause a mutation. Such fresh insertions are fairly rare events but one example has been described in the
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This note was uploaded on 11/22/2011 for the course CHEMISTRY CHM1025 taught by Professor Laurachoudry during the Fall '10 term at Broward College.

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deletion and insertion - deletion and insertion small i.e....

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