Follow the link for more information. Jump to navigation Jump to search This article is about the heritable unit for transmission of biological traits. A gene is a region of Sex linked genes definition that encodes function. A chromosome consists of a long strand of DNA containing many genes.
A human chromosome can have up to 500 million base pairs of DNA with thousands of genes. In biology, a gene is a sequence of DNA or RNA that codes for a molecule that has a function. During gene expression, the DNA is first copied into RNA. Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotypical traits. The concept of a gene continues to be refined as new phenomena are discovered. For example, regulatory regions of a gene can be far removed from its coding regions, and coding regions can be split into several exons.
The term gene was introduced by Danish botanist, plant physiologist and geneticist Wilhelm Johannsen in 1905. 8000 common edible pea plants, tracking distinct traits from parent to offspring. Prior to Mendel’s work, the dominant theory of heredity was one of blending inheritance, which suggested that each parent contributed fluids to the fertilisation process and that the traits of the parents blended and mixed to produce the offspring. Advances in understanding genes and inheritance continued throughout the 20th century.