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Determine the correctness or otherwise of the following Assertion (a) and the Reason (r)
Assertion : Cytoplasmic male sterility (cms) is invariably due to defect(s) in mitochondrial function.
Reason : cms can be overcome by pollinating a fertility restoring (Rf) plant with pollen from a non cms plant.
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- both (a) and (r) are true and (r) is the correct reason for (a)
- both (a) and (r) are true and (r) is not the correct reason for (a)
- (a) is false but (r) is true
- (a) is true but (r) is false
Correct Option: A
Cytoplasmic male sterility (CMS) is a condition under which a plant is unable to produce functional pollen. CMS is a maternally inherited trait that is often associated with unusual open reading frames (ORFs) found in mitochondrial genomes. Male fertility can be restored by nuclear-encoded fertility restorer (Rf) gene(s). These fertility-restorer genes are thought to block or compensate for cytoplasmic dysfunctions that are phenotypically expressed during pollen development. On the one hand, sterility results from mitochondrial genes causing cytoplasmic dysfunction, and on the other, fertility restoration relies on nuclear genes that suppress cytoplasmic dysfunction.
