This article is about B-chromosomes. For B-DNA, see B-DNA.
Siberian roe deer metaphase spread with B chromosomes
In addition to the normal karyotype, wild populations of many animal, plant, and fungi species contain B chromosomes (also known as supernumerary,accessory, (conditionally-)dispensable, or lineage-specific chromosomes).[1] By definition, these chromosomes are not essential for the life of a species, and are lacking in some (usually most) of the individuals. Thus a population would consist of individuals with 0, 1, 2, 3 (etc.) B chromosomes.[1] B chromosomes are distinct from marker chromosomes or additional copies of normal chromosomes as they occur in trisomies.
^ abWhite M.J.D. (1973). The chromosomes (6th ed.). London: Chapman & Hall. pp. 171 et seq. ISBN 0-412-11930-7.
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characteristic of some selfish genetic elements. Parasitic chromosomes are often Bchromosomes, such that they are not necessarily present in the majority of the species...
A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their...
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The X chromosome is one of the two sex chromosomes in many organisms, including mammals, and is found in both males and females. It is a part of the XY...
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containing HEGs as template. Both chromosomes will contain the HEGs after repair. B-chromosomes are nonessential chromosomes; not homologous with any member...
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Supernumerary chromosome could refer to: Bchromosome in some animals and plants Small supernumerary marker chromosome (sSMC) in humans This disambiguation...
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Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 80 million...
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