Office Assistant Tasks. 1  Answer phones, direct calls and take messages. 2  Operate office machines; photocopiers and scanners, facsimile machines, voice mail systems and personal computers. 3  Maintain and update filing, inventory, mailing and database systems. 4  Open, sort and route incoming mail, answer correspondence and prepare outgoing mail.
DNA mutations happen when there are changes in the nucleotide sequence that makes up the strand of DNA. This can be caused by random mistakes in DNA replication or even an environmental influence like UV rays or chemicals.
A mutation is a change in the base sequence of DNA that can affect the structure and function of proteins when they occur within a gene. Mutations can be spontaneously caused by copying errors during DNA replication or induced by exposure to external elements such as chemical mutagens, radiation or viruses. Cystic fibrosis is an example of a disease which can result from a nonsense mutation (this may not be the only cause though). 2  Frameshift mutations occur when the addition or removal of a base alters the reading frame of the gene.