Consequently, they are removed by splicing of exons. Eukaryotic coding sequence consists of exons, introns and untranslated regions whereas prokaryotic genes lack introns. Eukaryotic gene structure is mainly composed of two regions: coding sequence and the regulatory sequence. The multiple protein-coding sequences are transcribed together. In prokaryotes, operons are formed by grouping the functionally related genes. Some viruses are made up of RNA genes since their genetic material is RNA. The study of the properties of genes or group of genes is referred to as genetics. Most genes are made up of DNA but a few may be made of RNA. The concept of the gene and its pattern of inheritance originated with the findings of Gregor Mendel in 1860s. This is the central dogma of molecular biology. A gene sequence is transcribed into RNA RNA is translated into proteins which consequently determine traits. Thousands of genes can be found within a single DNA molecule of higher organisms. The genetic instructions transfer into progeny through genes via reproduction. It encodes an amino acid sequence of a specific protein and is recognized as the molecular unit of hereditary. What is the difference between Gene and GenomeĪ gene is a locus or a sequence stretch on the DNA polynucleotide strand. The key difference between gene and genome is that a gene is a locus on a DNA molecule whereas genome is a total nuclear DNA.ģ. This repetitive DNA also has a function in the gene regulation. A genome has many DNA sequences and these are called repetitive DNA. All gene sequences are called non-repetitive DNA.
This DNA is packed into chromosome structures. The entire nuclear DNA is called the genome of an organism. Humans have thousands of genes in their total DNA molecules. A gene is a sequence stretch of nucleotides which encodes a specific protein. The order of the nucleotide bases arranged in the polynucleotide chain determines the genetic instructions. Genetic information of a cell is stored in chemical form in DNA or RNA.
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