Genome
hideIn classical genetics, the genome of a diploid organism including eukarya refers to a full set of chromosomes or genes in a gamete; thereby, a regular somatic cell contains two full sets of genomes. In haploid organisms, including bacteria, archaea, viruses, and mitochondria, a cell contains only a single set of the genome, usually in a single circular or contiguous linear DNA (or RNA for retroviruses). In modern molecular biology the genome of an organism is its hereditary information encoded in DNA (or, for retroviruses, RNA).
The genome includes both the genes and the non-coding sequences of the DNA. The term was adapted in 1920 by Hans Winkler, Professor of Botany at the University of Hamburg, Germany. The Oxford English Dictionary suggests the name to be a portmanteau of the words gene and chromosome; however, many related -ome words already existed, such as biome and rhizome, forming a vocabulary into which genome fits systematically.
More precisely, the genome of an organism is a complete genetic sequence on one set of chromosomes; for example, one of the two sets that a diploid individual carries in every somatic cell. The term genome can be applied specifically to mean that stored on a complete set of nuclear DNA (i.e., the "nuclear genome") but can also be applied to that stored within organelles that contain their own DNA, as with the mitochondrial genome or the chloroplast genome. Additionally, the genome can comprise nonchromosomal genetic elements such as viruses, plasmids, and transposable elements. When people say that the genome of a sexually reproducing species has been "sequenced", typically they are referring to a determination of the sequences of one set of autosomes and one of each type of sex chromosome, which together represent both of the possible sexes. Even in species that exist in only one sex, what is described as "a genome sequence" may be a composite read from the chromosomes of various individuals. In general use, the phrase "genetic makeup" is sometimes used conversationally to mean the genome of a particular individual or organism. The study of the global properties of genomes of related organisms is usually referred to as genomics, which distinguishes it from genetics which generally studies the properties of single genes or groups of genes.
Both the number of base pairs and the number of genes vary widely from one species to another, and there is little connection between the two (an observation known as the C-value paradox). At present, the highest known number of genes is around 60,000, for the protozoan causing trichomoniasis (see List of sequenced eukaryotic genomes), almost three times as many as in the human genome.
An analogy to the human genome stored on DNA is that of instructions stored in a book:
For more information about Genome, read the full article at
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News tagged with genome
Time in a bottle: Scientists watch evolution unfold
Oct 18, 2009 |
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A 21-year Michigan State University experiment that distills the essence of evolution in laboratory flasks not only demonstrates natural selection at work, but could lead to biotechnology and medical research ...
Major insights into evolution of life reported
Aug 19, 2009 |
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(PhysOrg.com) -- Humans might not be walking the face of the Earth were it not for the ancient fusing of two prokaryotes -- tiny life forms that do not have a cellular nucleus. UCLA molecular biologist James ...
Ancient penguin DNA raises doubts about accuracy of genetic dating techniques
Nov 10, 2009 |
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Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been ...
Antarctic lake home to diverse community of viruses
Nov 11, 2009 |
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(PhysOrg.com) -- A study of the genetic structure of viruses in an Antarctic lake has revealed an astonishing genetic richness in the large number of viral families discovered.
Scientists decipher the 3-D structure of the human genome
Oct 08, 2009 |
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(PhysOrg.com) -- Scientists have deciphered the three-dimensional structure of the human genome, paving the way for new insights into genomic function and expanding our understanding of how cellular DNA folds ...
Genomic research shows Indians descended from two groups
Sep 23, 2009 |
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(PhysOrg.com) -- In a study published in the September 24th issue of Nature, an international team describes how they harnessed modern genomic technology to explore the ancient history of India, the world' ...
On the move: 'Jumping genes' create diversity in human brain cells
Aug 05, 2009 |
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Rather than sticking to a single DNA script, human brain cells harbor astonishing genomic variability, according to scientists at the Salk Institute for Biological Studies. The findings, to be published in ...
What drives our genes? Researchers map the first complete human epigenome
Oct 14, 2009 |
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Although the human genome sequence faithfully lists (almost) every single DNA base of the roughly 3 billion bases that make up a human genome, it doesn't tell biologists much about how its function is regulated. Now, researchers ...
Professor sequences his entire genome at low cost, with small team
Aug 10, 2009 |
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(PhysOrg.com) -- The first few times that scientists mapped out all the DNA in a human being in 2001, each effort cost hundreds of millions of dollars and involved more than 250 people. Even last year, when ...
A solution to Darwin's 'mystery of the mysteries' emerges from the dark matter of the genome
Oct 26, 2009 |
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Biological species are often defined on the basis of reproductive isolation. Ever since Darwin pointed out his difficulty in explaining why crosses between two species often yield sterile or inviable progeny (for instance, ...
A dead gene comes back to life in humans
Mar 06, 2009 |
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(PhysOrg.com) -- Researchers have discovered that a long-defunct gene was resurrected during the course of human evolution. This is believed to be the first evidence of a doomed gene - infection-fighting human ...
IBM Research Aims to Build Nanoscale DNA Sequencer (w/ Video)
Nanotechnology / Bio & Medicine
Oct 06, 2009 |
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(PhysOrg.com) -- In an effort to build a nanoscale DNA sequencer, IBM scientists are drilling nano-sized holes in computer-like chips and passing DNA strands through them in order to read the information contained ...
Sea lampreys jettison one-fifth of their genome
Jul 20, 2009 |
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(PhysOrg.com) -- Researchers have discovered that the sea lamprey, which emerged from jawless fish first appearing 500 million years ago, dramatically remodels its genome. Shortly after a fertilized lamprey ...
'Autoantibodies' may be created in response to bacterial DNA (w/Video)
Apr 27, 2009 |
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Autoimmune diseases have long been regarded as illnesses in which the immune system creates autoantibodies to attack the body itself. But, researchers at the California non-profit Autoimmunity Research Foundation (ARF) explain ...
'Tamed' virus wipes out cancer cells safely
May 22, 2009 |
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(PhysOrg.com) -- Scientists at Oxford University have tamed a virus so that it attacks and destroys cancer cells but does not harm healthy cells. The research funded by Cancer Research UK is published in the ...
