Gene

From WikiLectures

A gene is the basic unit of genetic information (the basic unit of heredity). It is a certain stretch of DNA (sequence of nucleotides) on a chromozome.

General characteristics of the gene[edit | edit source]

  • a gene can occur in different forms – alleles
  • we refer to the set of all alleles in the cell of a given individual as genotype
  • the set of all the DNA of a given organism is called the genome
  • the human genome consists of a nuclear genome and an extranuclear genome (mitochondrial)
  • genes are arranged linearly on chromosomes and their specific location (locus) is unchanging
  • all genes on one chromosome form a linkage group
  • it includes so-called exons and intrones (cut out during DNA editing)
Chromosome DNA developed.
Gene structure..

Gene species[edit | edit source]

  • genes can be divided into two basic groups according to function:
  1. Structural genes – encode the primary structure of proteins, such as proteins with a biochemical, physiological or structural function
  2. Genes for functional RNAs – their products, unlike structural genes, are not translated.
They are mainly genes for tRNA and rRNA (more about tRNA and rRNA on the RNA page).

Gene function[edit | edit source]

  • one gene can condition the creation of one specific trait (monogenic inheritance )
  • the determination of one trait by one gene occurs more rarely than the realization of a trait after the interaction of a larger number of genes (oligogenic, or polygenic inheritance)
  • more often, the formation of a trait depends on gene interactions, i.e. the specific form of the trait is determined by the alleles of several participating genes
  • another example of the multifacetedness of genetic information is the so-called gene familiesgene family is a group of genes with a similar sequence that have the same or similar biological function

Links[edit | edit source]

Related articles[edit | edit source]