A disease caused by an autosomal primary non-disjunction is

A disease caused by an autosomal primary non-disjunction is
  1. Down's syndrome
  2. Klinefelter's syndrome
  3. Turner's syndrome
  4. Sickle cell anemia

Solution

Non-disjunction is the failure of homologous chromosomes to disjoin or separate and move away to opposite poles. Non-disjunction of the 21st chromosome during oogenesis is the cause of Down's syndrome. It occurs due to the presence of an additional copy of chromosome no. 21 (trisomy of 21st chromosome) is humans.

Asked in: NEET 2017

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