CELL DIVISION
MEIOSIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Trisomy 18
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Trisomy 21
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Trisomy 13
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Trisomy 23
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Detailed explanation-1: -Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having an extra copy of a chromosome is ‘trisomy.’ Down syndrome is also referred to as Trisomy 21.
Detailed explanation-2: -Also known as Down syndrome, trisomy 21 is a genetic condition caused by an extra chromosome. Most babies inherit 23 chromosomes from each parent, for a total of 46 chromosomes. Babies with Down syndrome however, end up with three chromosomes at position 21, instead of the usual pair.
Detailed explanation-3: -There are three types of Down syndrome: trisomy 21 (nondisjunction), translocation and mosaicism. Trisomy 21 (nondisjunction) accounts for 95% of known cases of Down syndrome.