Question

Which one of the following characters does NOT belong to Down's Syndrome?

• A. Mild to moderate mental retardation
• B. Change in size and shape of RBCs
• C. Open mouth, protruding tongue, flat nose
• D. Poor skeletal development

Hint:

Recall the features of trisomy 21 and pick the one that belongs to a blood disorder instead.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept
Down's syndrome is trisomy of chromosome 21. It has a typical set of physical and mental features.

Step 2: Features of Down's syndrome
Mild to moderate mental retardation, a flat face and nose, a partly open mouth with a protruding furrowed tongue, short stature and poor skeletal development.

Step 3: Find the odd one out
A change in the size and shape of red blood cells is seen in blood disorders such as sickle-cell anaemia and thalassemia, not in Down's syndrome.

Final Answer:
Change in size and shape of RBCs does not belong to Down's syndrome. \[ \boxed{\text{(B) }\text{Change in size and shape of RBCs}} \]