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NEET2015ZoologyPrinciples of Inheritance and VariationActual

An abnormal human baby with 'XXX' sex chromosomes was born due to:

Options

  1. AFormation of abnormal sperms in the father
  2. BFormation of abnormal ova in the mother
  3. CFusion of two ova and one sperm
  4. DFusion of two sperms and ovum

Correct answer

B. Formation of abnormal ova in the mother

Step-by-step solution

Formation of abnormal ova i.e., 22 + XX in the mother will lead to birth of baby with 'XXX' genotype, due to chromosomal non disjunction in ova. Nondisjunction is the failure of the chromosomes to disjoin and move to opposite poles.

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