A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Genes carry information for particular characteristics, such as ear shape or eye colour. Different sets of genes carry information for different characteristics. There are many genes in a chromosome. Some genes act as instructions to make molecules called proteins. However, many genes do not code for proteins.
- In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases.
- An international research effort called the Human Genome Project, which worked to determine the sequence of the human genome and identify the genes that it contains, estimated that humans have between 20,000 and 25,000 genes.
- Every person has two copies of each gene, one inherited from each parent. Most genes are the same in all people, but a small number of genes (less than 1 percent of the total) are slightly different between people.
William Bateson introduced the term genetics in the year 1905. Later, Wilhelm Johannes was the first one who coined the term GENE in 1909. He was a Danish botanist. He named it as Gene to symbolise hereditary.
Genome Editing And CRISPR-Cas9 Technology
Characteristics determined by Genes
- Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population.
- Genes vary in size depending on the code or the protein they produce.
- All cells in the human body contain the same DNA. The difference between the cells occurs due to the different type of genes that are turned on and therefore produce a variety of proteins.
Reasons for hereditary
- Genes come in pairs in the same way as the chromosomes. Each parent of a human being carries two copies of their genes and each parent passes one copy of genes to their child. This is the reason why the child has many characteristics of both the parents like hair colour, same eyes etc.
Functions of Genes
- Genes control the functions of DNA and RNA.
- Proteins are the most important materials in the human body which not only help by being the building blocks for muscles, connecting tissue and skin but also takes care of the production of the enzyme.
- These enzymes play an important role in conducting various chemical processes and reactions within the body. Therefore, protein synthesis is responsible for all activities carried on by the body and are mainly controlled by the genes.
- Genes consist of a particular set of instructions or specific functions. For example, the globin gene was instructed to produce haemoglobin. Haemoglobin is a protein that helps to carry oxygen in the blood.
Also refer :
- Download the pdf of Important MCQs From the History Of Ancient India
- List Of Important Inscriptions In India
