What is the name of the genetic disorder caused by the presence of an extra chromosome 21?
Turner syndrome
Klinefelter syndrome
Down syndrome
Huntington's disease
Correct Answer : C
Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21. It is also known as trisomy 21, because affected individuals have three copies of chromosome 21 instead of the normal two.
The extra chromosome 21 in Down syndrome occurs due to a random error in cell division, which leads to the production of an abnormal gamete (egg or sperm) with an extra copy of the chromosome. When this gamete fuses with a normal gamete during fertilization, the resulting zygote has 47 chromosomes instead of the usual 46, and develops into a fetus with Down syndrome.
Down syndrome is characterized by a range of physical and intellectual symptoms, including developmental delays, intellectual disability, distinctive facial features, heart defects, and increased risk of certain medical conditions such as leukemia and Alzheimer's disease. However, the severity and expression of these symptoms can vary widely among affected individuals.
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Explanation
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Correct Answer is A
Explanation
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Correct Answer is A
Explanation
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Correct Answer is A
Explanation
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Correct Answer is D
Explanation
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Correct Answer is A
Explanation
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Deficiencies or abnormalities in insulin production or function can lead to a range of metabolic disorders, including type 1 and type 2 diabetes. In type 1 diabetes, the body does not produce enough insulin, while in type 2 diabetes, the body becomes resistant to the effects of insulin, leading to elevated levels of glucose in the blood.

Correct Answer is A
Explanation
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Correct Answer is C
Explanation
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Analysis of Other Options:
- A. Compound Light Microscope → Uses visible light to magnify samples but lacks the resolution and 3D detail seen in the image. ❌
- B. Transmission Electron Microscope (TEM) → Produces 2D images of ultra-thin sections, not detailed 3D surface views. ❌
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Correct Answer is B
Explanation
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Correct Answer is C
Explanation
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