Question
Assertion: B12 deficiency causes subacute combined degeneration of the spinal cord.
Reason: B12 deficiency causes degeneration of both the ascending and descending tracts of the spinal cord.
Reason: B12 deficiency causes degeneration of both the ascending and descending tracts of the spinal cord.
| A. |
Both assertion and reason are true and reason is correct explanation of assertion.
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| B. |
Both assertion and reason are true and reason is not the correct explanation of assertion.
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| C. |
Assertion is true and reason is false.
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| D. | Both assertion and reason is false. |
Show Answer
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Correct Answer » A Explanation |
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- Subacute combined degeneration (SCD) is a neurological complication of vitamin B12 deficiency.
- It occurs due to demyelination involving:
- Posterior (dorsal) columns → ascending sensory tracts
- Lateral corticospinal tracts → descending motor tracts
- Since both ascending and descending tracts are affected, it is called “combined” degeneration.
Thus:
- Assertion is true.
- Reason is also true.
- The reason correctly explains the assertion.