What is a gene?
With the translation of RNA, proteins are obtained capable of accelerating some chemical reactions in living beings or of constituting some structures or carrying out functions that cause the appearance of the different characters of an individual. Therefore, the manifestation of a character is due to the information provided by a piece of chromosome (gene).
A gene is a piece of DNA that contains the information necessary for a protein to be made, necessary for a specific character to be expressed in an individual.
If there is a change in the nucleotide sequence of DNA, an alteration in the synthesized protein can occur and change the characteristics of the individual. In this case, a genetic mutation will have occurred .
The proteins are composed of long chains of amino acids, and are determined by the number, type and how they are ordered the amino acids that constitute it. There are 20 different types of amino acids and each protein is characterized by having a certain number, type and order of these amino acids. It is something like the letters of the alphabet, with which you can write a great book or, with the same letters but arranged in a different way and in different numbers, a website that says what a gene is for 4th graders of ESO.