Mutations can't be controlled as they're spontaneous; they're unpredictable, random events. Each gene has a rate of spontaneous mutation which can be measured as the probability of a change in the DNA sequence within the timeframe of a single generation

By exposing the individual to mutagens which induce new mutations

Germ-line mutations are passed down to offspring since those mutations occur in the gametic cells. Somatic mutations are all mutations that don't occur in reproductive cells

1. Somatic mutations are inherited in the cell line that the mutation occured in. 2. Somatic mutation yields an organism that is a genetic mix (mosaic) of normal and mutant tissue. 3. Most cancers are the result of somatic mutation

Conditional mutations are mutations that produce phenotypic changes under specific (restrictive) conditions but not others (permissive conditions). A classification used in conditional mutations is known as temperature-sensitive mutations (whose expression depends on temperature)

It results in complete gene inactivation or in a completely nonfunctional gene product

It reduces the level of expression of a gene or activity of a product

It will increase the level of gene expression becasue it changes the regulation of the gene so that the gene product is overproduced

This kind of mutation qualitatively alters the action of a gene. These mutations can cause a gene to become active in a type of cell or tissue in which the gene is not normally active; this kind of expression is called ectopic expression

The pyrimidines are changed (T to C or vice versa)

Purines and pyrimidines interchange (A or G to C or T and vice versa)

Methylated cytosine can easy convert to thymine. By removing the NH₂ group from the metC, T can be obtained

These substitutions result in an amino acid being replaced with another

They don't affect the amino acid sequence

A nonsense mutation creates a new stop codon

Frameshift mutations shift the reading frame of the codons in the mRNA. If the amount of the added or deleted base sequences is divisible by three then there is not a significant effect but if the remainder of the sequence in question is 1 or 2 then there is a significant effect such as a faulty start codon or a premature stop codon

It is a mutant in the beta-globin gene which shifts a GAG sequence to GUG (glutamic acid is changed to valine)

People who are heterozygous for SCA are affected less by malaria than people who're free of the SCA alleles.

Dynamic mutations have extraordinary genetic instability because of trinucleotide repeat expansion (the continuous repeat of a codon). These are caused by replication slippage (the 3' end detaches and attaches later down the line which causes extensive trinucleotide repeats). Fragile X syndrome is a good example of this

The molecular symptoms primarily include tendency of the X chromosomes to fracture in cultured cells that are starved of DNA precursors. An expansion of a CGG TNS repeat has been found to be the culprit in this case

The excessive repeats cause loss of function so therefore the needed protein is essential in keeping individuals within the non-retarded phenotype. Most fragile X patients exhibit no FMR1 mRNA

Heterozygous daughters of heterozygous males will often have affected children of both sexes

It shuts down the transcription

A transposable element is a genetic element that can move (transpose) within the genome and could also cause modification in the expression of genes at or near its insertion site

Transposons are mobile DNA elements and they normally disrupt normal gene function

They transpose using an RNA intermediate that is made into DNA for transposition using reverse transcriptase (which the LTR encodes for)

While in direct orientation they can either result in deletions or free circles

The result will be an inversion mutation