Mutations are heritable changes in the DNA of cells that may occur in any living organism. All around us are mutagens, which is a chemical or physical agent in the environment that interacts with DNA and may cause a mutation. The following are a few prime examples of mutagens.


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Cadmium is an elemental transition metal, with the atomic number of 48. Inhalation or digestion can lead to deadly results, and smoking may create mutations in one's DNA, leading to the offspring possibly inheriting this mutation from the parent.

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Benzene is an organic compound (aromatic hydrocarbon) containing three double bonds, known as an alkene. Benzene has been known to cause cancer as well as other serious illnesses, such as bone marrow failure and leukemia. Even the smallest vapors are considered high risk, with possibility of becoming seriously ill.

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Radiation with a small enough wavelength and lots of energy are able to penetrate one's cells, allowing for the effects of radiation to occur, causing mutations.

Natural Causes of Mutations
Some natural causes of mutations include the sun (ultraviolet radiation), inaccurate DNA replication (the mRNA doesn't copy everything the DNA had coded in it), or it may be inherited by the parent.

Difference Between a Gene Mutation and a Chromosome Mutation
Gene mutations are only small, localized changes in the structure of a DNA strand (gene), they only affect individual geneson on a chromosome as well as potentially only one protein.
Chromosome mutations involve the arrangement of whole blocks of chromosomes rather than individual bases on a gene, and include whole sets of chromosomes, either gaining some or losing some.

How Gene Mutations Affect Cells/Organisms
Since mutations add, delete, or rearrange DNA, the nitrogenous bases in a certain DNA will also be affected. If even one nitrogenous base in a DNA sequence is changed, it may code for a whole different amino acid, or may even tell the DNA to "stop". This, in turn, could affect the whole cell and ultimately the organism itself, hindering its ability to do activities it would otherwise be able to do.

How Mutations Are Passed from One Generation to the Next
There are two general types of mutations, gametic mutations and somatic mutations. The latter involves mutations in the body cells, therefore these mutations are unable to be passed down during reproduction, but can still be multiplied when the host goes through cell division. Gametic mutations, on the other hand, will be contracted to all the cells in the parent and its offspring, which is how mutations are able to be passed from one generation to the next.


The significance of mutations are that they are involved in variations of DNA. Mutations may be: beneficial, neutral, or harmful for an organism. Mutations are heritable changes in the genetic information, meaning that off springs will have a tendency to inherit these mutations. Mutations are significant as they offer variety in a species. Without mutations, or variation for that matter, any small or drastic changes in the environment would be able to kill off whole species.
Each one of us humans are born with about 300 mutations. Most of these mutations are neutral, but some could be negative and potentially lethal. We must take care in refraining from exposure to mutagens as mutations often occur after a period of time.

A rabbit with a mutation
A rabbit with a mutation

A mutation is a heritable change in the DNA of cells which may add, delete, or rearrange DNA

An X-ray machine, which is a known mutagen
An X-ray machine, which is a known mutagen

A mutagen is a chemical or physical agent in the environment that interacts with DNA & may cause a mutation

A gene on a portion of DNA
A gene on a portion of DNA

A gene is a sequence of nitrogenous bases on a DNA molecule that codes for the type and order of amino acids in a protein and thus determines a trait

Genetic Code
The genetic code is the way in which cells store the information that allows them to function & that they pass from one generation to the next generation

Semi-Conservative Replication
Diagram explaining semi-conservative replication
Diagram explaining semi-conservative replication

Semi-conservative replication is the process of DNA replication where each of the two new DNA molecules contains one strand of the original DNA and one new strand