Q.61 Given below are two statements :
Statement I :
Auxins have been used commercially for prevention of fruit and leaf drop only.
Statement II :
In some plant species, seedless fruit are produced with the help of treatment
of unpollinated flower with auxins.
In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Both Statement I and Statement II are false
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
Statement I is false but Statement II is true, so the correct option is the last one. Auxins serve multiple commercial roles beyond just preventing fruit and leaf drop, while they indeed induce seedless fruits via parthenocarpy in unpollinated flowers.
Auxin Applications
Auxins like NAA and 2,4-D prevent premature abscission by inhibiting the formation of the separation layer at fruit/leaf bases, but they also promote rooting, weed control, and parthenocarpic fruit development.
Statement Evaluation
-
Statement I (False): The “only” qualifier fails—auxins enable weed killers (2,4-D), tissue culture rooting, and parthenocarpy, not solely drop prevention.
-
Statement II (True): Auxin treatment on unpollinated flowers triggers seedless fruit growth (parthenocarpy) in crops like tomatoes, grapes, and cucumbers by mimicking fertilization signals.​
Option Analysis
| Option |
Why Valid/Invalid |
Correct? |
| Both true |
Overstates Statement I by ignoring broader auxin uses. |
No ​ |
| Both false |
Denies proven parthenocarpy role in Statement II. |
No ​ |
| I true, II false |
Wrong on both counts per evidence. |
No ​ |
| I false, II true |
Matches expanded applications and parthenocarpy fact. |
Yes |
Auxins commercial prevention fruit leaf drop extends to seedless fruits from unpollinated flowers, key for horticulture and GATE Life Sciences plant hormone questions.
Broader Auxin Roles
Prevent drop via abscission inhibition; also rooting powders, herbicides, parthenocarpy.
Parthenocarpy Mechanism
Unpollinated flowers sprayed with IAA/NAA develop fruits without seeds by sustaining cell division sans fertilization.​
Exam Insight
Statement I’s exclusivity fails, II holds, picking option (4).​
