Genes are functional units of heredity as they are made of DNA. The chromosome is made of DNA containing many genes. Every gene comprises of the particular set of instructions for a particular function or protein coding. Speaking in usual terms, genes are responsible for heredity.GenesThere are about 30000 genes in each cell of the human body. DNA present in the gene comprises of only 2 percent of the genome. Many researches are made on the same that found the location of nearly 13000 genes on each of the chromosomes.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.