How many chromosomes does a person with Down syndrome have in each body cell?
Answer and explanation
Correct answer: A. 47
- Step 1: Trisomy 21 gives three copies of chromosome 21, so the total is 46 + 1 = 47.
Answer
47.
Why not the others: 46: this is the normal number. 45: this would be a missing chromosome, as in Turner syndrome. 48: this would be two extra chromosomes.
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