Which of the following is responsible for mental abnormalities in humans?

The chromosomal condition in Turner's syndrome is:

Ovum producing Klinefelter's syndrome shall have chromosome number:

Which one is not a feature of Down's syndrome?

Haploid chromosome number is 12. What is the number in a Monosomic?

Marriage between close relatives (consanguineous mating) should be avoided because it induces more: