Question

down sydrome big note​

Answer 1

Ciao,
it is an autosomal non.disjunction in man,during which 21st pair of chromosome fails to segregate,thus causing 24 chromosome in a gamete.and when this gamete fertilizes normal gamete the new individual will have 47 chromosomes.non.disjunction occurs in ova and is related with the age of mother mother of more age have more risk of having child with down's syndrome.
these individuals have flat ,broad face,squint eyes ,mental retardation,skin folded in inner corner and defective central nervous system.
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