![](https://steemitimages.com/DQmdiT423RwYDKfhBGwhK8UECAzBxATgYwyo2rShGZJNQdk/image.png)
<center>[source](http://meyersarch.com/wp-content/uploads/CGC-Mutation.jpg)</center>

Mutation is simply a spontaneous change to the materials that are responsible for carrying genetic information within the biological organism. From the description and characteristics of the cell's genetic material (the DNA in the nucleus), it is quite obvious that certain changes in the material such as base substitutions in a base triplet (the codon) may lead to changes in the products or the amino acid associated with them. Changes in the order of amino acids in protein may lead to a non-functional, malfunctional or novel protein.

There are several implications of mutation of the genetic materials in the cell. Few of them are explained as follows:

___
### Sickle cell anaemia
___

<div class="pull-left">https://steemitimages.com/DQmdwJrx2vdZwB6Hu46TrJVPXuoUu4FRT2EY6jT97251mR1/Sickle.jpg</div>

Fundamentally, the difference between the normal red blood cells and the abnormal or sickling red blood cell in man resulted from the differences in genetic code sequence which in turn results in amino acid substitution. The amino acid glutamic acid normally occupies position 6 on normal hemoglobin amino acid sequence whereas in abnormal or sickling hemoglobin a completely different amino acid valine is substituted in its place. It is known that different base sequences in form of triplet codes specify glutamic acid and valine. Phenotypically, this results in low number of red blood counts, episodic pains and re-occurence infections.

___
### Albinism
___
<div class="pull-right">https://steemitimages.com/DQmeet1mQnBSDGENvbBRejCboeoCwYKXMCJBXrAF4LE8Jio/610px-Superbowl_044.JPG</div>

This dependence of haemoglobin structure and function on the genetic code can be multiplied several times. The amino acid phenylalanine enters into a number of biochemical pathways that lead to various chemical end products; each pathway has many enzymes in form of proteins which of course are specified by triplet codes as described in the earlier example. As such, it is only normal that abnormal triplet codes may lead to non-functional proteins or enzymes such that a particular pathway may be blocked and the normal end products will fail to materialize. It is due to this that melanin (the skin pigments in human beings) is prevented from being made from phenylalanine thus leading to albinism.

Although the genetic material is quite stable, spontaneous changes of this material make novel form possible and explain some of the variations observed among living organisms. These variations are of course transmitted from generation to generation if it is not of debilitating consequences. That is, only mutations that are not deleterious are inheritable. In particular, if new varieties have special adaptive advantages like longevity, resistance to diseases and many other features, such new varieties will tend to multiply rapidly in the population.

___
### Organization of genetic materials in the cell
___
The genetic material carries genetic information in such an organized way at different levels of the evolutionary ladder. It is very simple and non-extensive in primitive organisms, the prokaryotes while it is more complex in the higher forms, the eukaryotes.

<div class="pull-left">https://steemitimages.com/DQmfL1Z2rDTFTKN5xKu2tWjhP21dc7vPLgCkqoXQDxqr3eK/f-d%200cfa6ca6bdccc9a09f3ffe60c5e3d777529c14771d85ab4cc4f712b1%2BIMAGE_THUMB_POSTCARD_TINY%2BIMAGE_THUMB_POSTCARD_TINY.1.jpg</div>

The genetic material is organized in organelles called chromosomes in all organisms. Chromosome simply means bodies that attract certain stains. In bacteria and lower algae, rgw chromosome is believed to be one simple linear or circular double helix of DNA and it is neither organized into a definite nucleus nor does it possess any division apparatus. However, in higher organisms like higher algae, fungi, lower animals and higher eukaryotes, the chromosomes are usually many, structurally more complex with division apparatus and organized in a definite nucleus.

The characteristics of chromosomes in plants and animals are quite similar. Chromosomes are visible in appropriately stained dividing cells under the light microscope. Its number is unrelated generally constant from cell to cell in one organism. Although totally unrelated organisms may have same chromosome number, it does not mean that their genetic materials will be identical. In some organisms, the chromosome may be big, while they may be small in others. Within same cell, certain chromosomes may be large while some are relatively small. The study or chromosomal details of cell is known as karyotyping. Below are the karyotyping of some named organisms;

<center>![](https://steemitimages.com/DQmQRXCRyZjeZhctDmCdr2BX2j5z2BV5wnbT4FQAqbgAwo4/image.png)</center>
<center>[human chromosome karyotype](http://content.tutorvista.com/biology_11/content/us/class11biology/chapter17/images/img51.jpeg)</center>

<center>![](https://steemitimages.com/DQmSYe4hfJSYwBYtFZuqMgavaYyh5dagqUexZh5DZhkh9TP/image.png)</center>
<center>[rabbit chromosome karyotype](https://www.researchgate.net/profile/Claire_ROGEL-GAILLARD/publication/10802442/figure/fig5/AS:279174473371680@1443571790003/Figure-1-GTG-banded-female-rabbit-karyotype-The-Y-chromosome-is-taken-from-a-separate.png)</center>



In diploid cells, that is somatic cells, each chromosome is present in duplicate. Each chromosome has a homologue from which it cannot be distinguished morphologically. But usually, a pair of homologues may be morphologically different from another pair. The differences may result from size differences, the location of the centromere, a primary constriction, intensity of staining or condensation, presence or absence of secondary constrictions and other morphoogical markers as they are collectively called. 

![](https://steemitimages.com/DQmRAUmNFYBwKEgLai5frSZdHPpniJ2L3UKQmKt2NPAKC4E/image.png)
<center>[types of chromosome](http://ib.bioninja.com.au/_Media/types-of-chromosomes_med.jpeg)</center>

The chromosome is said to be metacentric when the centromer is mre or less mid-way along the chromosome, acrocentric when it is near one end and telocentric when it is more or less at one end of the chromosome.

___
### References
___
[national library of medicine](https://ghr.nlm.nih.gov/condition/sickle-cell-disease)

[springer link](https://link.springer.com/chapter/10.1007/978-81-322-3673-3_3)

[jstor.org](https://www.jstor.org/stable/3883003)

[mrscp revision](http://mrcprevision.blogspot.com.ng/2012/02/sickle-cell-disease.html)

[myjoy online](https://www.myjoyonline.com/opinion/2015/September-7th/the-notes-of-a-sickle-cell-person-what-is-sickle-cell-disease.php)

[health line](https://www.healthline.com/health/albinism)

[nature.com](https://www.nature.com/scitable/topicpage/karyotyping-for-chromosomal-abnormalities-298)

___
### Image credits

[image 1](https://guardian.ng/wp-content/uploads/2016/09/Sickle.jpg)

[image 2](https://upload.wikimedia.org/wikipedia/commons/thumb/d/d8/Superbowl_044.JPG/610px-Superbowl_044.JPG)

[image 3](https://dr282zn36sxxg.cloudfront.net/datastreams/f-d%3A0cfa6ca6bdccc9a09f3ffe60c5e3d777529c14771d85ab4cc4f712b1%2BIMAGE_THUMB_POSTCARD_TINY%2BIMAGE_THUMB_POSTCARD_TINY.1)