Chromosomal non - disjunction responsible for all except?: (A) Down's syndrome, (B) Neurofibromatsis type 1, (C) Pradderwilli syndrome, (D) Angleman syndrome
Answer is B. Ans. is 'b' i.e., Neurofibromatosis type 1Nondisjunction Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division.There are threeforms of nondisjunction: Failure of a pair of homologous chromosomes to separate in meiosisFailure of sister chromatids to separate during meiosis II, andFailure of sister chromatids to separate during mitosis.