Q.33 Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A):
Pollen fixed in Formalin : Acetic acid : Alcohol can be used to ascertain fertility but not the viability.
Reason (R):
Pollen fertility refers to the ability of a plant to produce fertile pollen grains, whereas the viability refers to the ability to germinate and produce a pollen tube.
In the light of the above statements, choose the most appropriate answer from the options given below:
(1) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(2) Both (A) and (R) are correct but (R) is NOT the correct explanation of (A)
(3) (A) is correct but (R) is not correct
(4) (A) is not correct but (R) is correct
Pollen fixed in Formalin-Acetic-Alcohol (FAA) can assess fertility via staining but not viability, which requires germination tests. Reason (R) correctly distinguishes the two concepts, making option (1) the answer.
Option Analysis
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(1) Both (A) and (R) correct; (R) explains (A): Correct. FAA-fixed pollen allows acetocarmine staining to check fertility (intact/stained cytoplasm indicates fertile grains structurally), but viability (germination ability) needs live unfixed pollen; (R) explains this distinction directly.
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(2) Both correct but (R) not explanation: Incorrect. (R) precisely links why fixed pollen suits fertility (production check) but not viability (functional germination).
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(3) (A) correct, (R) incorrect: Incorrect. (R) accurately defines fertility as structural production capacity vs. viability as germination/pollen tube function.
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(4) (A) incorrect, (R) correct: Incorrect. (A) holds as fixation kills pollen, blocking live tests like in vitro germination for viability.
In competitive exams like GATE Life Sciences, the assertion reason question on pollen fertility vs viability using FAA-fixed pollen tests structural integrity but not germination. Both statements are correct, with (R) explaining (A) as the top choice.
Key Concepts
Pollen fertility assesses if the plant produces structurally sound grains (via staining post-FAA fixation: red-stained = fertile). Viability tests function: live pollen germinates, grows pollen tubes in media/semi-vivo setups.
Comparison Table
| Aspect |
Fertility |
Viability |
| Definition |
Ability to produce intact pollen grains |
Ability to germinate and form pollen tube |
| Test Method |
Staining (acetocarmine on fixed pollen) |
In vitro germination (live pollen) |
| FAA Fixed? |
Yes |
No |
| Measures |
Structural quality |
Functional vigor |
Exam Relevance
Fixed pollen suits quick fertility screening in breeding; viability reveals stress effects (e.g., heat). No correlation always exists between them, emphasizing separate tests.
