The origin and kinds of mutation

How does the mutation occur ?

Mutation is a change in the nature of the hereditary factors that control the traits of a living organism which results in a change in the living organism’s traits , changing the chemical composition of one or more genes leads to a change in the hereditary trait resulting from this gene .

 So , a new trait that never appeared in the parents appears , this change could be transmitted from generation to another , The mutation causes the appearance of  undesirable traits like the birth deformation in the human and the animal , And  the sterilization in the plants , The mutation causes the appearance of desirable change ( rare ) .

Kinds of mutations

Mutations are varied according to many factors which are the site of occurrence ( genetic mutation and chromosomal mutations ) , the inheritance ( Somatic mutation and Gamete mutations ) and the origin ( Spontaneous mutations and Induced mutations ) .

Genetic mutation

It is changing the chemical composition of one gene or more , The genetic mutation occurs when a change occurs in the nitrogenous bases of the gene , for example : If adenine ( A ) base is replaced with cytosine ( C ) base and thymine ( T ) is replaced with guanine ( G ) .



The genetic mutation causes the protein that shows the hereditary trait is not formed , so , the trait disappears or a protein of another type is formed , which leads to the appearance of a new trait .

For example : The grey mice have melanin pigment , but the white mice do not have this pigment due to a change in the gene composition responsible for this trait ( mutation happened ) .

The origin of the mutation

The spontaneous mutation

The spontaneous mutation is a mutation that occurs due to the influence of the surrounding environment , It occurs without the interference of the human being , Its percentage is very low .

The spontaneous mutation occurs due to the influence of the surrounding environment like exposure to the chemical substances , high or very low temperature , And the radiation such as X- rays , atomic rays .

The importance of spontaneous mutation 

It causes the natural variations between the genera and the species of the animals and variations plants , where the new traits which are produced from the mutation occurrence are inherited across the successive generations , This produces new individuals with different traits .

The induced mutation

The induced mutation is a mutation which is controlled by the human being to obtain desirable traits , It is important to obtain desirable traits in specific living organisms especially in the plants such as ( the formation of fruits , large in size , better in taste and free of seeds ) .

Bio-technology collaborates with the traditional ways to combat the malnutrition

Around 500000 people every year are affected by losing their sight , and this is due to the deficiency in vitamin ( A ) , It is one of the important elements of nutrition whose deficiency leads to the malnutrition .

Deficiency in vitamin ( A ) is widespread in those who depend on eating rice because rice does not contain pro-vitamin ( A ) or what is known as carotene ( The substance that is changed into vitamin ( A ) in the body ) .

Solving this problem is done by producing rice that contains pro-vitamin ( A ) , This is done by inserting the genes that result in the creation of the pro- vitamin ( A ) compound inside the tissues that store the starch in the plant seeds .

So , Inserting carotene gene produces rice containing carotene , Inside the human body , It is converted into vitamin A .

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