A: In some plants flowering is either quantitatively or qualitatively dependent on exposure to low temperature.
R: Low temperature treatment shortens vegetative phase in some plants
In the following questions a statement of assertion (A) is followed by a statement of reason (R).
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
3. If Assertion is true statement but Reason is false, then mark (3)
4. If both Assertion and Reason are false statements, then mark (4)
  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false

Subtopic:  Vernalization (OLD NCERT) |
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Plants growing in a partially dark environment will grow toward light in a response called phototropism. Which of the following statements is true regarding phototropism?
1. It is caused by an electrical signal.
2.  One chemical involved is ethylene.
3.  Auxin causes a growth increase on one side of the stem.
4. Auxin causes a decrease in growth on the side of the stem exposed to light.
 
Subtopic:  Growth Hormones & Auxin |
 78%
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Which of the following statements applies to plant growth regulators?
1. They only act by altering gene expression
2. They often have a multiplicity of effects
3. They function independently of other hormones.
4. They directly control plant protein synthesis and assembly.
 
Subtopic:  Growth Hormones & Auxin |
 58%
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According to modern ideas about phototropism in plants,
1.  light causes auxin to accumulate on the shaded side of a plant stem.  
2.  auxin indirectly inhibits elongation of plant stem cells
3.  auxin is produced by the apical meristem of the coleoptile and moves downward.
4.  all hormones move downward via the xylem.
Subtopic:  Growth Hormones & Auxin |
 68%
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A: Photomodulation of flowering is a phytochrome regulated process.
R:  Active form of phytochrome (Pfr) directly induces floral induction in shoot buds
In the following questions a statement of assertion (A) is followed by a statement of reason (R).
1.  If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
2.  If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
3.  If Assertion is true statement but Reason is false, then mark (3)
4.  If both Assertion and Reason are false statements, then mark (4)
Subtopic:  Photoperiodism (OLD NCERT) |
 65%
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Vernalisation 
A. Enables the plant to have sufficient time to reach maturity 
B. Depends not only on a combination of light but also on their relative duration 
C. Prevents precocious reproductive development late in the growing season 
D. Refers specially to the promotion of flowering by a period of low temperature 
E. Phenomenon occurs by changing light and temperature 
Choose the correct answer from the options given below: 
1. A, C, and E only 
2. A, C, D, and E only 
3. A, B, C, and D only 
4. A, C, and D only 
Subtopic:  Vernalization (OLD NCERT) |
From NCERT
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The phenomenon that prevents precocious reproductive development late in the growing season of a plant is:
A. Vernalisation
B. Thermoregulators
C. Photoreceptors
D. Seed dormancy
E. Plant inhibitors
Choose the correct answer from the options given below:
1. C only
2. A only
3. D only
4. E & B only
Subtopic:  Vernalization (OLD NCERT) |
 78%
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A plant bends towards the source of light when exposed to light on only one side. Which of the following is the best explanation of the phenomenon?
1. They need light for photosynthesis
2. The apices of their stems are attracted by light
3. Some auxin accumulates on the shaded side to induce greater cell elongation on that side
4. Light stimulates the cells on the illuminated side to increase in length
Subtopic:  Growth Hormones & Auxin |
 69%
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Match List I with List II
List I List II
A. Indole Acetic Acid I. Increase length of grapes stalks
B. Zeatin II. Hastens fruit ripening in tomatoes
C. Gibberellic acid III. Overcome apical dominance
D. Ethephon IV. Rooting in stem cuttings
Choose the correct answer from the option given below:
1. A-II, B-I, C-IV, D-III
2. A-IV, B-II, C-I, D-III
3. A-IV, B-III, C-I, D-II
4. A-III, B-IV, C-II, D-I


 
Subtopic:  Auxin Function | Gibberellin | Ethylene |
 88%
From NCERT
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Seedlings would not have been able to emerge out of the soil into the open if it were not for the:
1. Climactic respiration
2. Washing away of ABA
3. Pressure due to imbibitions
4. Mycorrhizal symbionts
Subtopic:  Seed Dormancy (OLD NCERT) |
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