Mutations - errors in the genetic code

Christiane Fux studied journalism and psychology in Hamburg. The experienced medical editor has been writing magazine articles, news and factual texts on all conceivable health topics since 2001.In addition to her work for, Christiane Fux is also active in prose. Her first crime novel was published in 2012, and she also writes, designs and publishes her own crime plays.

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Mutations are changes in the genetic make-up. They can occur, for example, when there are errors in cell division. Even if the genetic information is simply read off, the genetic code can get mixed up (spontaneous mutation). In addition, there are genetic changes that are triggered, for example, by metabolic products in the body, but above all radiation or certain chemicals. If the germ cells are affected by a mutation, the genetic deviation is passed on to the offspring.

There are different types of mutations:

In the case of a gene or point mutation, only individual genes are changed. The sequence of the building blocks (base pairs) that make up the genetic code can get mixed up. Individual modules can also be lost or additional ones can be added. Such mutations can arise as soon as the information is read.

A chromosome mutation occurs when the chromosome structure has fundamentally changed. For example, entire sections can be lost, or certain segments duplicate or migrate to another part of the chromosome. Sometimes segments of other chromosomes also accumulate. These serious mutations often occur as a result of radiation damage or in contact with certain chemical substances. Unlike the point mutations, they can often be seen under an electron microscope.

With a genome mutation, the number of chromosomes is changed. This can be a completely multiple set of chromosomes, as often occurs in plants in particular. However, entire chromosomes can also be missing or the cell contains one chromosome too many. The best-known example in humans is the trisome 21, also called Down syndrome. Genome mutations arise when the cell divides, especially when the germ cells are formed and the double set of chromosomes has to be halved (meiosis).

Negative consequences

Depending on how often the affected cell divides, mutations can cause great damage, go unnoticed or - like a four-leaf clover - have neither advantages nor disadvantages. If the mutation takes place in the germ cells, however, it can lead to hereditary diseases. Others can cause cancer. Because of this, the body is constantly busy repairing minor mutations. In doing so, enzymes cut out faulty structures from the DNA and replace them with correct sections.

Engine of evolution

However, in rare cases, mutations can also be beneficial. They then prevailed in the course of evolution. However, this only applies if they have taken place in the germ cells. Without the constantly changing genome, living beings would not be able to develop new properties and adapt to changing environmental conditions. In this respect, mutations are the engine of evolution.