Aneuploidy - Aneuploidy Cells that have extra chromosomes...

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Aneuploidy Cells that have extra chromosomes or chromosomes missing are aneuploid . Two types of aneuploidy are discussed below. Monosomy refers to a condition in which there is one chromosome is missing. It is abbreviated 2N - 1. For example, monosomy X is a condition in which cells have only one X chromosome. A trisomy has one extra chromosome and is abbreviated 2N + 1. Trisomy 21 is an example of a trisomy in which cells have an extra chromosome 21. Monosomies and trisomies usually result from nondisjunction during meiosis but can also occur in mitosis. They are more common in meiosis 1 than meiosis 2. They are generally lethal except monosomy X (female with one X chromosome) and trisomy 21 (Down’s Syndrome). Affected indivisuals have a distinctive set of physical and mental characteristics called a syndrome. For example, trisomy 21 is Down syndrome. Oogenesis is more likely to continue than spermatogenesis when a chromosomal abnormality occurs. As a result, 80% to 90% of aneuploid (extra chromosomes or chromosomes missing)
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This note was uploaded on 01/04/2012 for the course BSC BSC1005 taught by Professor Orlando,rebecca during the Fall '10 term at Broward College.

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Aneuploidy - Aneuploidy Cells that have extra chromosomes...

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