CBSE 2025 · Region 5 · Set 1 · Q23 · 3 marks
During a medical investigation, an infant was found to possess an extra copy of chromosome no. 21. Identify the disorder the child is suffering from. Describe the symptoms the child is likely to develop later in life.
Marking-scheme solution
• Disorder is Down’s Syndrome
• Symptoms: - Short statured with small round head
furrowed tongue
partially open mouth.
palm is broad with characteristics palm crease retarded physical growth/psychomotor development/mental development.
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CBSE Class 12 Biology past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.