Q1. Assertion: Growth can be defined mathematically.
Reason: Arithmetic growth follows the linear equation Lt = L0 + rt.
Correct Answer: (a)
The equation is the mathematical definition of the rate.
Q2. The only gaseous plant growth regulator is:
Correct Answer: (c)
Ethylene is described as a simple gaseous PGR.
Q3. Assertion: Auxins are used in tea plantations and hedge-making.
Reason: They promote the growth of lateral buds by removing apical dominance.
Correct Answer: (d)
Assertion is true, but the reason is false. Removing shoot tips (decapitation) allows lateral growth; Auxins themselves cause apical dominance which inhibits lateral buds.
Q4. Cytokinins were discovered as ______ from autoclaved herring sperm DNA.
Correct Answer: (b)
Cytokinins were discovered as kinetin (a modified form of adenine).
Q5. The cells proximal to the meristematic zone represent the phase of:
Correct Answer: (b)
The cells proximal (just next, away from the tip) to the meristematic zone represent the phase of elongation.
Q6. Assertion: Auxin controls xylem differentiation.
Reason: Auxins are produced by the growing apices of stems and roots.
Correct Answer: (b)
Both are true statements from the text, but the site of production doesn't explain the role in xylem differentiation.
Q7. Development includes all changes from ______ to ______.
Correct Answer: (c)
Development includes all changes an organism goes through from germination of the seed to senescence.
Q8. In a sigmoid curve, the initial slow growth phase is called:
Correct Answer: (b)
The initial growth is slow (lag phase).
Q9. Assertion: Cytokinins help in the delay of leaf senescence.
Reason: They promote nutrient mobilisation.
Correct Answer: (a)
Nutrient mobilisation is the mechanism by which cytokinins delay aging/senescence.
Q10. Which statement is true for seed survival? (i) Absence of favorable conditions leads to suspended growth. (ii) Seeds resume metabolic activities when conditions return. (iii) This is called development.
Correct Answer: (a)
Suspended growth is rest/dormancy, not development.
Q11. Which PGR is used to induce immediate stomatal closure in leaves under water stress?
Correct Answer: (c)
ABA stimulates the closure of stomata.
Q12. Match the term to example in figure 13.1:
A. Cotyledons
Food storage
B. Hypocotyl
Part below cotyledons
C. Epicotyl
Part above cotyledons
Correct Answer: (a)
Based on Figure 13.1 labels.
Q13. The primary CO2 acceptor in C3 plants is:
Correct Answer: (a)
From unit intro: Ribulose bisphosphate (RuBP) is the 5-carbon ketose sugar acceptor.
Q14. Which of the following is correct regarding growth? (i) It is irreversible. (ii) It is a permanent increase in size. (iii) It is accompanied by metabolic processes.
Correct Answer: (b)
Definition of growth from section 13.1.
Q15. Mathematically, arithmetic growth is expressed as:
Correct Answer: (b)
The equation for arithmetic growth is Lt = L0 + rt.
Q16. Match the growth curve components:
Column-I
Column-II
A. Lag phase
(I) Slow initial growth
B. Log phase
(II) Rapid exponential growth
C. Stationary phase
(III) Limited nutrient supply
Correct Answer: (a)
Phases of the sigmoid curve.
Q17. Assertion: Seed germination is the first step of plant growth.
Reason: Seeds germinate only under favorable conditions like proper water and temperature.
Correct Answer: (b)
Both are true, but favorable conditions are a requirement for germination, not the explanation of it being the 'first step' of development.
Q19. The 'bakanae' disease of rice seedlings was caused by the fungal pathogen:
Correct Answer: (b)
Bakanae (foolish seedling) disease is caused by Gibberella fujikuroi.
Q20. Correct statements about 'Auxin' migration: (i) Produced by growing apices. (ii) They migrate to the regions of their action. (iii) Isolated first from urine.
Correct Answer: (a)
Based on section 13.4.3.1.
Q21. Who isolated Auxin from tips of coleoptiles of oat seedlings?
Correct Answer: (b)
Auxin was isolated by F.W. Went from tips of coleoptiles of oat seedlings.
Q22. Turgidity of cells is important for growth because it helps in:
Correct Answer: (b)
The text states: 'Turgidity of cells helps in extension growth.'
Q23. Plant growth regulators (PGRs) are also known as:
Correct Answer: (b)
PGRs are variously described as plant growth substances, plant hormones or phytohormones.
Q24. Increase in surface area is the parameter used to measure growth in:
Correct Answer: (b)
An increase in surface area denotes growth in a dorsiventral leaf.
Q25. The act leading to maturation to perform specific functions is termed as:
Correct Answer: (b)
Maturation to perform specific functions is termed differentiation.
Q26. Assertion: High temperature destroys enzymatic activity.
Reason: Heat causes the denaturation of proteins.
Correct Answer: (a)
Denaturation is the chemical process that stops enzyme function.
Q27. Ethephon is a source of ______ used in agriculture.
Correct Answer: (c)
Ethephon is the most widely used compound as a source of ethylene.
Q28. Match the growth stage with its characteristic:
Q29. The ability of plants to follow different pathways in response to environment to form different kinds of structures is:
Correct Answer: (b)
This ability is called plasticity.
Q30. Which of the following is true for 'Senescence'? (i) It is the terminal phase of life. (ii) Delayed by cytokinins. (iii) Promoted by ethylene (in organs).
Correct Answer: (a)
Aging/death phase properties.
Q31. Assertion: Heterophylly in buttercup is due to the environment.
Reason: Shapes of leaves produced in air are different from those produced in water.
Correct Answer: (a)
The difference in media (air vs water) is the environmental factor leading to different structures.
Q32. Match the cell process with the term:
Column-I
Column-II
A. Regaining division capacity
(I) Differentiation
B. Maturing for function
(II) Dedifferentiation
C. Maturing again after division
(III) Redifferentiation
Correct Answer: (a)
Sequence of cell developmental terms.
Q33. Which statements regarding Cytokinins are correct? (i) They were discovered as kinetin. (ii) Zeatin was isolated from corn-kernels. (iii) They help overcome apical dominance. (iv) Found in regions of rapid cell division.
Correct Answer: (a)
All statements are facts mentioned in the text.
Q35. Identify the correct phylum/group being described? (i) Small molecules of diverse chemical composition. (ii) Also called phytohormones. (iii) Five major groups: Auxins, Gibberellins, Cytokinins, ABA, Ethylene.
Correct Answer: (a)
This is the description of Plant Growth Regulators.
Q36. Growth is measurable at the cellular level by an increase in the amount of:
Correct Answer: (b)
Growth, at a cellular level, is principally a consequence of increase in the amount of protoplasm.
Q37. A single maize root apical meristem can give rise to more than ______ new cells per hour.
Correct Answer: (b)
The text provides this specific numerical value for maize root apical meristem.
Q38. Match the synthetic Auxin with its name:
Column-I
Column-II
A. NAA
(I) Naphthalene acetic acid
B. 2, 4-D
(II) 2, 4-dichlorophenoxyacetic
Correct Answer: (a)
Full names of synthetic auxins provided in section 13.4.3.1.
Q39. Assertion: Plant growth is generally indeterminate.
Reason: Plants have the capacity for unlimited growth throughout their life due to meristems.
Correct Answer: (a)
Plants grow throughout life because meristems always add new cells.
Q40. Identify correct statements for 'Dedifferentiation': (i) Cells regain division capacity. (ii) Occurs under certain conditions. (iii) Example: formation of cork cambium.
Correct Answer: (a)
Definition from section 13.2.
Q41. Assertion: Dedifferentiation allows differentiated cells to regain the capacity to divide.
Reason: Interfascicular cambium is formed from fully differentiated parenchyma cells.
Correct Answer: (a)
The example provided in the text explains the process of dedifferentiation.
Q42. Assertion: The lag phase is the period of initial slow growth in a sigmoid curve.
Reason: It is followed by an exponential increase in growth rate.
Correct Answer: (b)
Both are true parts of the sigmoid curve description, but the fact it is followed by exponential phase doesn't explain why it is slow initially.
Q43. Identify the correct statements for 'Arithmetic Growth': (i) Only one daughter cell continues to divide. (ii) It produces a sigmoid curve. (iii) It is expressed as Lt = L0 + rt.
Correct Answer: (a)
Arithmetic growth produces a linear curve, not sigmoid.
Q44. Which conditions are essential for growth according to the text? (i) Water and Oxygen. (ii) Nutrients. (iii) Optimum temperature.
Correct Answer: (a)
Section 13.1.5 lists these as necessary conditions.
Q45. Cells of the ______ zone attain their maximal size in terms of wall thickening and protoplasmic modifications.
Correct Answer: (c)
The cells of the maturation zone attain their maximal size and modifications.
Q46. Select correct statements for Gibberellins: (i) They are all acidic. (ii) GA3 remains the most intensively studied form. (iii) They cause elongation of apple shape. (iv) Delay senescence.
Correct Answer: (a)
All points are characteristically true for GAs.
Q47. A fruit that shows a rise in respiration rate during ripening is called:
Correct Answer: (b)
The rise in rate of respiration during ripening is called respiratory climactic (associated with ethylene).
Q48. Apical dominance is caused by:
Correct Answer: (b)
In most higher plants, the growing apical bud inhibits the growth of lateral buds, a phenomenon called apical dominance, mediated by auxins.
Q49. Plant growth is unique because plants retain the capacity for:
Correct Answer: (b)
Plants retain the capacity for unlimited growth throughout their life due to the presence of meristems.
Q50. The first product of CO2 fixation in C4 plants is:
Correct Answer: (b)
From unit intro: Oxaloacetic acid (OAA) is the first product in C4 pathway.
Q51. Spray of which PGR can increase the yield of sugarcane by as much as 20 tonnes per acre?
Correct Answer: (c)
Spraying sugarcane crop with gibberellins increases the length of the stem, increasing yield.
Q52. Assertion: Differentiation in plants is open.
Reason: Cells arising out of the same meristem always have the same structure at maturity.
Correct Answer: (c)
Reason is false; 'cells/tissues arising out of the same meristem have different structures at maturity' depending on location.
Q53. Which of the following is a stress hormone?
Correct Answer: (d)
Abscisic acid (ABA) is called the stress hormone because it increases the tolerance of plants to various kinds of stresses.
Q54. In dicotyledonous plants, increase in the girth of organs is due to:
Correct Answer: (c)
Lateral meristems, vascular cambium and cork-cambium cause the increase in the girth of organs.
Q55. Match the following for absolute vs relative growth:
Term
Description
A. Absolute rate
(I) Comparison of total growth
B. Relative rate
(II) Growth per unit initial parameter
Correct Answer: (a)
Definitions from section 13.1.4.
Q57. Correct statements about 'Absolute vs Relative Growth Rate': (i) Fig 13.7 shows two leaves A and B. (ii) Both increase area by 5 cm2. (iii) Relative growth rate of leaf A is higher because initial size was smaller.
Correct Answer: (a)
Leaf A (5 to 10) = 100% increase; Leaf B (50 to 55) = 10% increase. Relative rate of A is higher.
Q58. In the equation W1 = W0 ert, 'r' represents:
Correct Answer: (c)
'r' is the relative growth rate and is also the measure of the ability of the plant to produce new plant material (efficiency index).
Q59. 2, 4-D is widely used as a/an:
Correct Answer: (b)
2, 4-D is widely used to kill dicotyledonous weeds (herbicides).
Q60. Assertion: Oxygen is essential for growth.
Reason: It helps in releasing metabolic energy essential for growth activities.
Correct Answer: (a)
Growth requires energy (ATP), which is released through oxygen-dependent respiration.
Q61. Which of the following statements about 'Plant Growth' is true? (i) It is generally indeterminate. (ii) New cells are added by meristems. (iii) It is defined as the 'closed form of growth.'
Correct Answer: (a)
It is the 'open form' of growth, not closed.
Q62. Regarding Plasticity, which is true? (i) Cotton shows different leaf shapes in different life stages. (ii) Buttercup shows different shapes based on air/water media. (iii) Heterophylly is a type of plasticity.
Correct Answer: (a)
Definitions from section 13.3.
Q63. Assertion: Sigmoid curve is typical for all cells, tissues and organs of a plant.
Reason: It is a characteristic of living organisms growing in a natural environment.
Correct Answer: (a)
Sigmoid curve represents the natural progression of growth from slow to rapid to stationary.
Q64. Which are correct regarding the discovery of PGRs? (i) Most were accidental discoveries. (ii) started with Charles Darwin. (iii) Darwin used canary grass coleoptiles.
Correct Answer: (a)
Section 13.4.2 details these accidental discoveries.
Q65. Which are correct for 'Kranz Anatomy' (unit intro)? (i) Bundle sheath cells form several layers. (ii) Large number of chloroplasts. (iii) Impervious to gaseous exchange.
Correct Answer: (a)
Based on C4 leaf description.
Q66. Which is true for growth in roots? (i) Occurs in meristematic zone. (ii) Parallel line technique detects zones of elongation. (iii) Zones A, B, C, D immediately behind apex elongate most.
Correct Answer: (a)
Based on Figure 13.3 description.
Q68. The growth of a pollen tube is measured in terms of its:
Correct Answer: (c)
Growth of a pollen tube is measured in terms of its length.
Q69. Regarding PGR interaction: (i) PGRs can act synergistically. (ii) PGRs can act antagonistically. (iii) ABA acts as an antagonist to GAs.
Correct Answer: (a)
Interaction patterns in plant growth regulation.
Q70. The process of 'bolting' (internode elongation just prior to flowering) is promoted by:
Correct Answer: (b)
Gibberellins promote bolting in beet, cabbages and plants with rosette habit.
Q71. Which are correct for 'Ethephon'? (i) Aqueous solution is used. (ii) Readily absorbed by plants. (iii) Releases ethylene slowly.
Correct Answer: (a)
Agricultural properties of ethephon source.
Q72. Assertion: Growth is measurable.
Reason: It is easy to measure the increase in protoplasm directly.
Correct Answer: (c)
Reason is false because 'increase in protoplasm is difficult to measure directly'.
Q73. Which statements about Auxins are true? (i) isolated first from human urine. (ii) IAA and IBA are natural auxins. (iii) Promote flowering in pineapples. (iv) widely used to kill monocot weeds.
Correct Answer: (a)
2, 4-D is used to kill dicotyledonous weeds, not monocots.
Q74. The form of growth where new cells are always being added to the plant body by the activity of meristems is called:
Correct Answer: (b)
This form of growth is called the 'open form of growth.'
Q75. The typical growth curve for all cells, tissues, and organs of a plant in a natural environment is:
Correct Answer: (b)
A sigmoid curve is characteristic of living organisms growing in a natural environment.
Q76. Identify true statements for 'Tracheary elements': (i) Formed via differentiation. (ii) Cells lose protoplasm. (iii) Develop lignocellulosic secondary walls.
Correct Answer: (a)
Structural changes described in section 13.2.
Q77. Heterophylly in cotton, coriander and larkspur is an example of:
Correct Answer: (b)
In these plants, leaves of the juvenile plant are different in shape from those in mature plants (phases of life).
Q78. Assertion: ABA helps seeds to withstand desiccation.
Reason: ABA inhibits seed germination.
Correct Answer: (b)
Both are true functions related to seed dormancy/survival, but inhibition of germination is not the cause of desiccation resistance.
Q79. Which of the following is correct? (i) Melvin Calvin received Nobel Prize in 1961. (ii) He mapped the carbon assimilation pathway. (iii) He used C14 isotopes.
Correct Answer: (a)
From unit introduction about Melvin Calvin.
Q80. Development in plants is the sum of two processes:
Correct Answer: (b)
The text explicitly states: 'Development is the sum of two processes: growth and differentiation.'
Q81. Match the PGR groups:
Column-I
Column-II
A. Growth Promoters
(I) Auxin, Gibberellin, Cytokinin
B. Growth Inhibitors
(II) ABA, Ethylene (largely)
Correct Answer: (a)
Classification of PGRs based on function.
Q83. Match the enzyme with its reaction from unit intro:
Column-I
Column-II
A. RuBisCO
(I) C3/C4 pathway enzyme
B. Carbonic anhydrase
(II) 600,000 molecules/sec
Correct Answer: (a)
Standard enzymes described in the unit.
Q84. Assertion: Gibberellins are used in the brewing industry.
Reason: GA3 is used to speed up the malting process.
Correct Answer: (a)
The use of GA3 to speed up malting is why they are valued in the brewing industry.
Q85. Identify correct statements for Ethylene: (i) Enhances respiration during ripening. (ii) Promotes horizontal growth of seedlings. (iii) Initiates germination in peanut seeds. (iv) Accelerates abscission in cotton.
Correct Answer: (a)
Ethylene's diverse roles are all correctly listed here.
Q86. The first step in the process of plant growth is:
Correct Answer: (b)
According to the text, 'The first step in the process of plant growth is seed germination.'
Q87. Thinning of cotton, cherry, and walnut is accelerated by:
Correct Answer: (c)
Ethephon (ethylene source) accelerates abscission in these fruits.
Q88. Assertion: ABA is called the stress hormone.
Reason: It stimulates the closure of stomata and increases plant tolerance to various kinds of stresses.
Correct Answer: (a)
The function of stomatal closure under stress defines the name.
Q89. Match the natural source of Cytokinin:
Column-I
Column-II
A. Kinetin
(I) herring sperm DNA
B. Zeatin
(II) corn-kernels / coconut milk
Correct Answer: (a)
Standard sources mentioned in the text.
Q90. Which are correct for Abscisic Acid (ABA)? (i) Inhibits seed germination. (ii) Antagonist to GAs. (iii) Closes stomata. (iv) Discovered for its role in regulating dormancy.
Correct Answer: (a)
Standard description of ABA's inhibitory/survival roles.
Q91. Growth is defined as a/an:
Correct Answer: (b)
Growth is defined as an irreversible permanent increase in size of an organ or its parts or even an individual cell.
Q92. Regarding 'Geometric Growth', which are correct? (i) Both progeny cells retain division capacity. (ii) Initial growth is fast (lag phase). (iii) Final size depends on the initial size.
Correct Answer: (a)
Initial growth is slow (lag phase) in geometric growth.
Q93. The 'efficiency index' in geometric growth is represented by:
Correct Answer: (c)
In the equation W1 = W0 ert, r is referred to as the efficiency index.
Q94. Assertion: Growth in terms of cell number is exemplified by watermelon.
Reason: Watermelon cells can increase in size by up to 3,50,000 times.
Correct Answer: (d)
Assertion is false; watermelon growth is an example of increase in cell size, not cell number.
Q95. Match the specific Auxin use:
Column-I
Column-II
A. Pineapple
(I) Promote flowering
B. Tomato
(II) Induce parthenocarpy
C. Tea plantation
(III) Apical dominance application
Correct Answer: (a)
Agricultural applications mentioned in the text.
Q96. Which PGR promotes nutrient mobilisation to help delay leaf senescence?
Correct Answer: (b)
Cytokinins promote nutrient mobilisation which helps in the delay of leaf senescence.
Q97. Identify correct features of 'Aleurone layer' (unit intro): (i) It is a proteinous layer. (ii) Part of monocot seed.
Correct Answer: (a)
Standard anatomical knowledge from the unit.
Q98. Assertion: Ethylene enhances the respiration rate during ripening of fruits.
Reason: This rise in rate of respiration is called respiratory climactic.
Correct Answer: (a)
The definition and the process are correctly linked.
Q99. Formation of cork cambium from fully differentiated parenchyma cells is an example of:
Correct Answer: (b)
When living differentiated cells regain the capacity to divide, it is called dedifferentiation.
Q100. Assertion: Ethylene is a gaseous PGR.
Reason: It is primarily used to break dormancy in seeds.
Correct Answer: (b)
Both are true, but being gaseous is a physical state, not a functional reason for breaking dormancy.
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