Question

A karyotype of a human suffering from a certain disorder is given below:

Answer the following:

• [(a)] Identify the disorder.
• [(b)] Write the symptoms of the disorder.
• [(c)] Give reason for such a disorder.

Hint:

Down’s syndrome results from an extra chromosome 21. It’s a chromosomal numerical abnormality.

Answer 1

1. [(a)] The disorder is Down’s syndrome (Trisomy 21).
2. [(b)] Symptoms include:
   • Mental retardation.
   • Short stature.
   • Broad face.
   • Furrowed tongue.
   • Physical growth delay.
3. [(c)] The disorder occurs due to trisomy of chromosome 21, caused by non-disjunction during gamete formation, leading to an extra chromosome 21.