Question

Identify chromosomal disorder caused due to non-disjunction of 21st number of chromosome and enlist its symptoms.

Hint:

Down syndrome is diagnosed via karyotyping, showing three copies of chromosome 21.

Answer 1

Step 1: Non-disjunction of the 21st chromosome during meiosis results in an extra copy of chromosome 21, causing Down syndrome (Trisomy 21). Step 2: Symptoms include: - Intellectual disability (mild to moderate). - Characteristic facial features: flat face, slanted eyes, small ears. - Congenital heart defects (e.g., atrial septal defect). - Short stature and reduced muscle tone. - Single transverse palmar crease and short fingers.