[Biology Class Notes] on Gene Definition Pdf for EXAM

Genes are a series of Nucleotides in RNA and DNA. Genes are regarded as the unit of heredity which is responsible for carrying characteristics and traits from parents to children. The genes are DNA fragments known as Deoxyribonucleic Acid. The body is made up of many cells that have structures called chromosomes. The genes are constrained within the chromosomes which lie within the nucleus of the cell. The chromosome is made up of thousands and thousands of genes.

Chromosomes

The chromosomes appear in thread-like structures which are present within the cells of plants and animals. The chromosome consists of the protein and the DNA. The structure of chromosomes has the capability of tightly wrapping the DNA in the cell as, without the wrapping, the DNA is too lengthy for fitting within the cell. The human cell comprises 23 pairs of chromosomes, thus making a total of 46 chromosomes. 

The proteins are the building block of the body and they are also responsible for producing enzymes. The enzymes are responsible for carrying out various functions as well as chemical reactions in the body. The body function depends largely on the type and amount of protein that the body is capable of synthesizing. This is why genes play a crucial role in the process of protein synthesis and the genes are also present in the chromosomes. 

Chemical Structure of the Genes

All organisms are made up of DNA except for some viruses that are made of RNA – Ribonucleic Acid. The DNA looks like a twisted ladder that is composed of nucleotides. The sides of the ladder are made using Phosphates and Sugars and the horizontal steps of the ladder called rungs are made up of pairs of nitrogenous bases. These bases are called Adenine (A), Cytosine (C), Thymine (T), and Guanine (G). The Adenine is on one of the sides of the ladder bind and Thymine is at the other side of the ladder thus forming the A-T ladder rung. 

The Function of the Genes

The genes are needed for the synthesis of the proteins. Beyond that, the genes also perform various other functions. The genes that do not participate in the synthesis of protein are formed in the RNA. The micro RNA that does not undergo protein formation assists in gene regulation. Some of the major functions that are provided by the genes include transcription, translation, gene expression, and replication and mutation.