NEETBiologyPrinciples of Inheritance and VariationMCQ+4 / −1
A women with 47 chromosomes due to three
copies of chromosome 21 is characterized by -
- ASuperfemaleness
- BTurner's syndrome
- CTriploidy
- DDown's syndrome
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Correct answer: D
A woman with 47 chromosomes due to three copies of chromosome 21 is characterized by Down's syndrome, which is Option D.
Here's a brief explanation of each option :
- Option A, Superfemaleness: This term is sometimes colloquially used for a condition known as Triple X syndrome, where a female has an extra X chromosome (47,XXX instead of the typical 46,XX). It's not associated with three copies of chromosome 21.
- Option B, Turner's syndrome: This is a condition where a female partially or completely lacks one of the two X chromosomes (usually represented as 45,X instead of 46,XX). It's unrelated to having an extra copy of chromosome 21.
- Option C, Triploidy: This is a rare chromosomal disorder where individuals have three copies of every chromosome (69 chromosomes in total), not just an extra copy of chromosome 21.
- Option D, Down's syndrome: This is the correct answer. Down syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It's the most common chromosome abnormality in humans.
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