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 ) .
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 .