chromosome /chro·mo·some/ (kro´mah-sōm) in animal cells, a structure in the nucleus containing a linear thread of DNA which transmits genetic information and is associated with RNA and histones; during cell division the material composing the chromosome is compactly coiled, making it visible with appropriate staining and permitting its movement in the cell with minimal entanglement; each organism of a species is normally characterized by the same number of chromosomes in its somatic cells, 46 being the number normally present in humans, including the two (XX or XY) which determine the sex of the organism. In bacterial genetics, a closed circle of double-stranded DNA which contains the genetic material of the cell and is attached to the cell membrane; the bulk of this material forms a compact bacterial nucleus.chromoso´mal .jpg)
X chromosome
X chromosome,
X chromosome,
X chromosome
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Chromosome. (A), Long, threadlike interphase chromatin in nucleus. (B), Giemsa-stained, partially condensed chromatid in late prophase. (C), Giemsa-stained, fully condensed chromatid in metaphase; note that some of the sub-bands visible in late prophase have condensed into single bands. (In B and C, only one of a pair of sister chromatids is shown.)
bivalent chromosome see bivalent (2).
homologous chromosomes a matching pair of chromosomes, one from each parent, with the same gene loci in the same order.
Ph1 chromosome , Philadelphia chromosome an abnormality of chromosome 22, characterized by shortening of its long arms (the missing portion probably translocated to chromosome 9); present in marrow cells of patients with chronic granulocytic leukemia.
ring chromosome a chromosome in which both ends have been lost (deletion) and the two broken ends have reunited to form a ring-shaped figure.
sex chromosomes those associated with sex determination, in mammals constituting an unequal pair, the X and the Y chromosome.
somatic chromosome autosome.
X chromosome a sex chromosome, carried by half the male gametes and all female gametes; female diploid cells have two X chromosomes.
Y chromosome a sex chromosome, carried by half the male gametes and none of the female gametes; male diploid cells have an X and a Y chromosome.
X chromosome
One of the two sex chromosomes (the other is Y) that determine a person's gender. Normal males have both an X and a Y chromosome, and normal females have two X chromosomes.
Mentioned in: Cutis Laxa, Fragile X Syndrome, Glucose-6-Phosphate Dehydrogenase Deficiency, X-Linked Agammaglobulinemia
X chromosome,
a sex chromosome that in humans and many other animals is present in both sexes, appearing singly in the cells of normal males and in duplicate in the cells of normal females. The chromosome is present in all of the female gametes and in half of the male gametes, is much larger than the Y chromosome, and has many sex-linked genes associated with clinically significant disorders, such as hemophilia, Duchenne's muscular dystrophy, and Hunter's syndrome. Compare Y chromosome.
X chromosome,
n a sex chromosome that in humans and many other species is present in both male and female. The male somatic cell consists of one X chromosome and one Y chromosome; the female somatic cell carries two X chromosomes. All female gametes carry the X chromosome, whereas half of the male gametes possess the X chromosome and the other half the Y chromosome.
chromosome
in animal cells, a structure in the nucleus, containing a linear thread of deoxyribonucleic acid (DNA), which transmits genetic information and is associated with ribonucleic acid and histones.
During cell division the material composing the chromosome is compactly coiled, making it visible with appropriate staining and permitting its movement in the cell with minimal entanglement. Each organism of a species is normally characterized by the same number of chromosomes in its somatic cells. The diploid numbers (number of total chromosomes per cell) are cattle—60, sheep—54, horse—64, donkey—62, pig—38, dog—78, cat—38, human—46. The chromosomes are arranged in pairs and one of the pairs is the sex chromosomes (XX or XY), which determines the sex of the organism. See also heredity.
compound chromosome
a genetic engineering procedure which produces two chromosomes in one of which the left arms of the two original chromosomes are joined together and the two original right arms are also joined together; used in genetic control of insect populations.
homologous c's
the chromosomes of a matching pair in the diploid complement that contain alleles of specific genes.
lampbrush chromosome
so named because of the bristling appearance given them by many open loops of chromatin along the extended chromosome.
ring chromosome
a chromosome in which both ends have been lost (deletion) and the two broken ends have reunited to form a ring-shaped figure.
sex c's
the chromosomes responsible for determination of the sex of the individual that develops from a zygote, in mammals constituting an unequal pair, the X and the Y chromosome.
somatic chromosome
autosome.
submetacentric chromosome
see submetacentric.
W chromosome
sex chromosome in animals such as poultry in which the female is the heterogametic state, the male has the ZZ genotype and the female the ZW genotype.
X chromosome
the female sex chromosome, being carried by half the male gametes and all female gametes; female diploid cells have two X chromosomes, the male has the XY genotype.
Y chromosome
the male sex chromosome, being carried by half the male gametes and none of the female gametes; male diploid cells have an X and a Y chromosome; females carry the XX genotype.
Z chromosome
sex chromosome in animals, such as poultry, in which the female is the heterogametic sex; the male has the ZZ genotype and the female the ZW genotype.
X chromosome
A sex chromosome with 2 copies in normal ♀ and one copy in normal ♂. Cf Y chromosome.
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