Human genetics: State the total chromosome number found in individuals with Down's syndrome (Trisomy 21). Full question: Number of chromosomes present in Down's syndrome is what? Choose the correct option.

Difficulty: Easy

Correct Answer: 47

Explanation:

Concept / Cause
Down's syndrome is typically due to trisomy 21 (an extra copy of chromosome 21), yielding a total of 47 chromosomes (karyotype 47,+21).

Common pitfalls
Confusing total count (47) with pair count (23 pairs + 1 extra chromosome 21).

Final Answer
47.

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