Patau syndrome
...(eggs and sperm). An error in cell division called
nondisjunction can result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 13. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child wi...
Nondisjunction
In biology ,
nondisjunction is the failure of a chromosome to split correctly during meiosis . This results in the production of gametes which have either more or less of the usual amount of genetic material, and is a common mechanism for trisomy or monosomy . Nond...
Klinefelter's syndrome
...chromosome abnormality in males (specifically, a
nondisjunction ); sufferers have a pair of X sex chromosomes instead of just one. It is named after Harry Klinefelter , the medical researcher who first described this syndrome in 1942 . Human males usually have an XY karyotype . The XXY chromosome arrangement...
Down syndrome
... of genetic disorders , of which trisomy 21 (a
nondisjunction ) is the most representative, causing highly variable degrees of learning difficulties and physical disabilities . It is named for John Langdon-Down , the British doctor who first described it. Contents showTocToggle("show","hide") 1...
Trisomy
... Trisomy 21 (47,XX,+21) is caused by a meiotic
nondisjunction event. A normal egg has one copy of each chrom...presented three times instead of twice. Caused by
nondisjunction during cell division . Related Terms: Diploid ... Full article >>> Trisomy 18 (...
Nondisjunction
... >>> Nondisjunction In biology ,
nondisjunction is the failure of a chromosome to split correct...ell division ... Full article >>>
nondisjunction The failure of chromosomes to separate properly during cell division . The unequal segregation ...
Human
...ble. Full article >>> In human s,
nondisjunction is most often associated with the 21st chromosome , producing a disease known as Down's syndrome (also referred to as trisomy 21). Full article >>> Human This article is about human s of the last 30,000 years. For other uses, se...
Homologous chromosomes
...ase of mitotic or meiotic division s (see also
nondisjunction ). Disposable soma theory ... Full article >>> During Metaphase I, homologous chromosomes will line up. A karyotype can be made by cutting and arranging photomicrographs of the homologous chromosomes thus revealed at Metaph...
Homologous chromosome
...ase of mitotic or meiotic division s (see also
nondisjunction ). Disposable soma theory ... Full article >>> During Metaphase I, homologous chromosome s will line up. A karyotype can be made by cutting and arranging photomicrographs of the homologous chromosome s thus revealed at Me...
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