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1 : Which part of the Venus fly trap responds to touch?
A
:
Glands
B
:
Lobes
C
:
Tentacles
D
:
Trichomes
2 : Which structure in sundew plants captures insects?
A
:
Hood
B
:
Root hairs
C
:
Dew-covered tentacles
D
:
Lobes
3 : If a plant has interveinal chlorosis, which nutrient may be deficient?
A
:
Copper
B
:
Iron
C
:
Sulfur
D
:
Phosphorus
4 : A plant is grown in soil poor in nitrogen. What symptom is most expected?
A
:
Dark green leaves
B
:
Stunted growth
C
:
Rapid flowering
D
:
Leaf curling
5 : Which statement is true for all insectivorous plants?
A
:
They are heterotrophic
B
:
They don't perform photosynthesis
C
:
They trap insects for energy
D
:
They are autotrophic but use insects for nutrients
6 : Which three nutrients are primarily used to build organic compounds?
A
:
N, K, P
B
:
Fe, Mn, Cu
C
:
C, H, O
D
:
Ca, Mg, S
7 : Which is the correct pair of micronutrient and its deficiency symptom?
A
:
Iron - stunted roots
B
:
Zinc - interveinal chlorosis
C
:
Manganese - leaf drop
D
:
Copper - reduced growth
8 : What is the function of calcium in plants?
A
:
ATP production
B
:
Sugar storage
C
:
Cell wall stability
D
:
Photosynthesis
9 : What type of plants trap and digest insects for nitrogen?
A
:
Autotrophs
B
:
Heterotrophs
C
:
Insectivorous
D
:
Chemotrophs
10 : What are macronutrients?
A
:
Needed in small amounts
B
:
Secondary minerals
C
:
Required in large amounts
D
:
Used for reproduction
11 : Which nutrient forms the central atom in a chlorophyll molecule?
A
:
Iron
B
:
Nitrogen
C
:
Magnesium
D
:
Calcium
12 : Where is palisade tissue found in a leaf?
A
:
Lower epidermis
B
:
Below upper epidermis
C
:
Near veins
D
:
Inside stomata
13 : What is the role of nitrogen in plants?
A
:
Root elongation
B
:
Photosynthesis
C
:
Protein synthesis
D
:
Lignin formation
14 : What happens to stomata at night?
A
:
They open widely
B
:
They close
C
:
They remain unchanged
D
:
They secrete wax
15 : Which cells contain chloroplasts and control stomatal movement?
A
:
Mesophyll cells
B
:
Guard cells
C
:
Root hairs
D
:
Trichomes
16 : Where are guard cells located?
A
:
Xylem vessels
B
:
Leaf cuticle
C
:
Around stomata
D
:
Inside phloem
17 : What is the function of stomata in plants?
A
:
Water conduction
B
:
Nutrient absorption
C
:
Gaseous exchange
D
:
Light reflection
18 : Which nutrient helps regulate water balance in plants?
A
:
Zinc
B
:
Calcium
C
:
Potassium
D
:
Molybdenum
19 : Why are guard cells called hydraulic valves?
A
:
They break water molecules
B
:
They transport glucose
C
:
They open/close using water pressure
D
:
They store ions
20 : How do plants prevent water loss during the night?
A
:
Increase respiration
B
:
Block xylem flow
C
:
Close stomata
D
:
Release K+ into soil
21 : In what condition would stomata likely remain closed during the day?
A
:
Humid morning
B
:
High CO2 levels
C
:
Dry, hot weather
D
:
During rain
22 : What would happen if guard cells lose water rapidly?
A
:
Stomata remain open
B
:
Photosynthesis increases
C
:
Stomata close
D
:
K+ influx increases
23 : Which mechanism enables efficient gas diffusion inside leaves?
A
:
Thick cuticle
B
:
Dense trichomes
C
:
Air spaces in spongy mesophyll
D
:
High sugar concentration
24 : How does palisade mesophyll assist photosynthesis?
A
:
Provides CO₂
B
:
Supports root growth
C
:
Maximizes light absorption
D
:
Opens stomata
25 : What triggers K+ uptake in guard cells?
A
:
Red light
B
:
Blue light
C
:
Darkness
D
:
UV light
26 : Why is the starch-sugar hypothesis insufficient alone?
A
:
It ignores chloroplasts
B
:
It does not explain cell death
C
:
It fails to explain rapid turgor changes
D
:
It excludes role of K+
27 : How does the influx of K+ affect stomata?
A
:
Causes stomata to close
B
:
Reduces cell size
C
:
Increases osmotic pressure
D
:
Enhances chlorophyll breakdown
28 : Why does water enter guard cells during stomatal opening?
A
:
Increased CO₂ concentration
B
:
Active loss of starch
C
:
Decrease in osmotic potential
D
:
Passive light absorption
29 : Which issue would be affected first in wilted herbaceous plants?
A
:
Xylem
B
:
Parenchyma
C
:
Sclerenchyma
D
:
Phloem
30 : Why is lignin important in plants growing in windy areas?
A
:
Helps seed dispersal
B
:
Increases photosynthesis
C
:
Prevents water loss
D
:
Provides mechanical strength
31 : Which plant tissue is best suited for manufacturing ropes?
A
:
Parenchyma
B
:
Xylem
C
:
Collenchyma
D
:
Sclerenchyma
32 : How can knowledge of collenchyma help agriculture?
A
:
Prevents seed loss
B
:
Improves grain color
C
:
Enhances stem flexibility
D
:
Increases flower size
33 : What is the importance of turgor pressure in soft plant parts?
A
:
Absorbs light
B
:
Aids reproduction
C
:
Provides support
D
:
Helps in respiration
34 : How do xylem vessels support the plant body?
A
:
Conduct sugar
B
:
Produce starch
C
:
Transport water
D
:
Make leaves green
35 : Why are sclerenchyma cells mostly dead?
A
:
Thin cell wall
B
:
Lack of chloroplast
C
:
Fully lignified walls
D
:
No vacuoles
36 : Which feature differentiates sclereids from fibers?
A
:
Found in phloem
B
:
Contain chloroplasts
C
:
Smaller in size
D
:
Present in epidermis
37 : How do collenchyma support young plant parts?
A
:
Secondary wall thickening
B
:
Lignin deposition
C
:
Turgor pressure
D
:
Cell wall corner thickening
38 : A plant with delayed flowering and browning of leaves may lack:
A
:
Potassium
B
:
Phosphorus
C
:
Iron
D
:
Boron
39 : A plant shows weak stalks and yellow spots on old leaves. Which nutrient is likely deficient?
A
:
Sulfur
B
:
Magnesium
C
:
Calcium
D
:
Potassium
40 : Where are collenchyma cells usually located?
A
:
Root hairs
B
:
Leaf veins
C
:
Epidermis
D
:
Stem cortex
41 : Which of the following tissues lacks secondary cell walls?
A
:
Sclerenchyma
B
:
Xylem
C
:
Collenchyma
D
:
Phloem
42 : What compound is responsible for the rigidity of sclerenchyma walls?
A
:
Cellulose
B
:
Lignin
C
:
Pectin
D
:
Starch
43 : What happens if external pressure is applied to a solution?
A
:
Ψw decreases
B
:
Ψw increases
C
:
Ψw becomes zero
D
:
Ψw becomes undefined
44 : Which plant tissue helps in maintaining turgor pressure?
A
:
Sclerenchyma
B
:
Collenchyma
C
:
Parenchyma
D
:
Xylem
45 : How does Ψw influence root absorption of water?
A
:
Lower Ψw in roots draws water from soil
B
:
Higher Ψw in roots pushes water out
C
:
Ψw in roots is always constant
D
:
Ψw blocks water uptake
46 : Why is Ψw important for transpiration?
A
:
Helps gas exchange
B
:
Facilitates light absorption
C
:
Drives water upward
D
:
Reduces root uptake
47 : What does a steep water potential gradient indicate?
A
:
Slow water flow
B
:
Faster water flow
C
:
No water flow
D
:
Water moving upward only
48 : In which direction will water move in soil-plant-air continuum?
A
:
From air to soil
B
:
From root to soil
C
:
From high to low Ψw
D
:
From low to high Ψw
49 : What causes pressure potential to build up in plant cells?
A
:
Salt uptake
B
:
Water entry
C
:
Cell division
D
:
Loss of solutes
50 : Why does water move into plant cells by osmosis?
A
:
Lower Ψw inside cell
B
:
Higher Ψw inside cell
C
:
Equal Ψw on both sides
D
:
Random diffusion
51 : Which factor would increase Ψw in a plant cell?
A
:
Increase in solute
B
:
Decrease in ΨP
C
:
Entry of water
D
:
Loss of turgor
52 : How does pressure potential affect Ψw?
A
:
It always decreases Ψw
B
:
It stabilizes Ψw
C
:
It increases Ψw
D
:
It has no role
53 : Why does the addition of solutes lower water potential?
A
:
It increases pressure
B
:
It reduces kinetic energy of water
C
:
It makes Ψs more negative
D
:
It increases volume
54 : What is the value of solute potential (Ψs)?
A
:
Always positive
B
:
Always zero
C
:
Always negative
D
:
Varies randomly
55 : How does water move in terms of Ψw?
A
:
From low to high Ψw
B
:
From high to low Ψw
C
:
Randomly
D
:
Does not move
56 : What determines water potential in plant cells?
A
:
Only solute concentration
B
:
Only pressure
C
:
Solute and pressure potential
D
:
Turgor pressure only
57 : What is the value of water potential for pure water?
A
:
One
B
:
Zero
C
:
Negative
D
:
Infinite
58 : What is water potential symbolized by?
A
:
Ψs
B
:
ΨP
C
:
Ψw
D
:
Ψt
59 : What structural feature makes vessels efficient in water transport?
A
:
Thick walls
B
:
No protoplast
C
:
Perforation plates
D
:
Root hairs
60 : Why is the TACT mechanism considered passive?
A
:
It uses ATP
B
:
It needs carrier proteins
C
:
It depends on root pressure
D
:
It does not use energy directly
61 : In drought conditions, which xylem property helps water stay continuous?
A
:
Diffusion
B
:
Perforation
C
:
Adhesion and cohesion
D
:
Photosynthesis
62 : Why are xylem fibers important in trees?
A
:
They absorb nutrients
B
:
They allow gas exchange
C
:
They provide mechanical strength
D
:
They conduct food
63 : What happens if transpiration stops completely?
A
:
Water moves faster
B
:
Photosynthesis increases
C
:
Upward water flow stops
D
:
More minerals are absorbed
64 : What role do bordered pits play in tracheids?
A
:
Water storage
B
:
Lateral water movement
C
:
Blocking pathogens
D
:
Retaining minerals
65 : Which pathway bypasses both apoplast and symplast?
A
:
Root hair route
B
:
Endodermal flow
C
:
Vacuolar pathway
D
:
Capillary rise
66 : Why is the TACT mechanism important in tall plants?
A
:
Helps in root growth
B
:
Maintains water flow against gravity
C
:
Reduces transpiration
D
:
Increases photosynthesis
67 : Why do parenchyma cells become turgid?
A
:
Due to lignin
B
:
Water moves into vacuole
C
:
Elongation of cell wall
D
:
Thicker walls
68 : Why does the apoplast pathway stop at the endodermis?
A
:
Absence of water
B
:
Casparian strips block it
C
:
No xylem nearby
D
:
Cells die here
69 : Which pathway involves movement through cell walls?
A
:
Apoplast
B
:
Symplast
C
:
Vacuolar
D
:
Endodermal
70 : Which xylem element is dead and provides support?
A
:
Tracheid
B
:
Vessel
C
:
Xylem parenchyma
D
:
Xylem fiber
71 : What are plasmodesmata?
A
:
Xylem fibers
B
:
Cell wall thickenings
C
:
Cytoplasmic strands
D
:
Root hairs
72 : What is the main function of xylem in plants?
A
:
Photosynthesis
B
:
Transport of sugars
C
:
Water and mineral conduction
D
:
Nutrient storage
73 : Which part of the root absorbs most of the water and minerals?
A
:
Root cap
B
:
Root hairs
C
:
Root cortex
D
:
Endodermis
74 : Why is the pressure-flow theory important in agriculture?
A
:
Helps in irrigation systems
B
:
Improves nutrient absorption
C
:
Develops better fertilizers
D
:
Aids in crop yield improvement
75 : How does the sieve tube structure relate to function?
A
:
Thick walls provide strength
B
:
Sieve areas allow nutrient flow
C
:
Narrow structure stores sugars
D
:
Compact structure reduces water loss
76 : What happens if osmotic pressure differences are reduced?
A
:
Water will not move
B
:
Transpiration stops
C
:
Sugar transport is inefficient
D
:
Xylem transports sugars
77 : How does the pressure-flow theory assist in plant growth?
A
:
It explains water transport
B
:
It supports cellular functions with nutrients
C
:
It promotes photosynthesis
D
:
It helps nutrient storage
78 : What surrounds the vacuole and regulates ion transport in parenchyma?
A
:
Cell wall
B
:
Tonoplast
C
:
Cytoplasm
D
:
Plasma membrane
79 : What happens when sucrose is unloaded at the sink?
A
:
Osmotic pressure at the source increases
B
:
Water potential at the sink decreases
C
:
Water moves into xylem
D
:
Turgor pressure increases
80 : Why does water follow sucrose from source to sink?
A
:
Active transport
B
:
Osmosis due to osmotic pressure
C
:
Absorption from surrounding cells
D
:
By diffusion alone
81 : How does the pressure-flow theory explain sucrose movement?
A
:
Through diffusion
B
:
Osmotic pressure differences
C
:
Active transport of water
D
:
Transpiration pull
82 : Why does sucrose move from mesophyll to companion cells?
A
:
To reduce water potential
B
:
To increase sucrose in sieve tubes
C
:
To store sugars
D
:
To promote osmotic pressure
83 : What process moves water into sieve tubes at the source end?
A
:
Active transport
B
:
Diffusion
C
:
Osmosis
D
:
Evaporation
84 : Which component of phloem helps translocate sugars?
A
:
Tracheids
B
:
Sieve tube elements
C
:
Phloem fibres
D
:
Xylem parenchyma
85 : Which tissue in plants transports sucrose?
A
:
Xylem
B
:
Phloem
C
:
Cortex
D
:
Epidermis
86 : What is the role of companion cells in phloem?
A
:
Transport sugars
B
:
Supply ATP and proteins
C
:
Store sugars
D
:
Form sieve areas
87 : What is the primary function of phloem?
A
:
Transport of water
B
:
Transport of sugars
C
:
Transport of minerals
D
:
Transport of oxygen
88 : How does the use of auxins in cuttings affect plant propagation?
A
:
It promotes root growth and callus formation
B
:
It inhibits root growth and leaf formation
C
:
It induces leaf senescence
D
:
It provides bud initiation
89 : How can gibberellins be used to improve crop yields?
A
:
By promoting faster leaf senescence
B
:
By increasing cell division and elongation in fruits
C
:
By delaying fruit ripening
D
:
By inhibiting root growth
90 : How are cytokinins useful in plant tissue culture?
A
:
They inhibit cell division and root formation
B
:
They promote bud initiation and shoot growth
C
:
They delay leaf senescence
D
:
They break seed dormancy
91 : What application of abscisic acid is used in agriculture?
A
:
To promote flowering in long-day plants
B
:
To protect plants from drought stress
C
:
To increase the rate of seed germination
D
:
To promote leaf expansion
92 : How is ethylene used in the commercial production of fruit?
A
:
To prevent fruit ripening
B
:
To delay leaf senescence
C
:
To induce fruit ripening
D
:
To promote fruit growth
93 : How does gibberellin affect rosette plants?
A
:
It promotes bolting (flowering)
B
:
It inhibits seed germination
C
:
It causes leaf senescence
D
:
It reduces root growth
94 : Why does ethylene inhibit stem growth?
A
:
It increases the levels of cytokinins
B
:
It reduces cell division in stems
C
:
It promotes apical dominance
D
:
It stimulates cell elongation in stems
95 : Why does gibberellin promote flowering in long day plants?
A
:
It increases auxin production
B
:
It substitutes for red light, which is essential for flowering
C
:
It inhibits abscission in flowers
D
:
It reduces leaf senescence
96 : How does abscisic acid help during water stress?
A
:
Promotes leaf senescence
B
:
Closes stomata to conserve water
C
:
Stimulates fruit ripening
D
:
Promotes seed dormancy
97 : What is ethylene's main function in plants?
A
:
Promote root growth
B
:
Break seed dormancy
C
:
Stimulate fruit ripening
D
:
Delay bud initiation
98 : What does abscisic acid (ABA) mainly regulate in plants?
A
:
Promotes growth of roots and shoots
B
:
Inhibits stem and root growth during stress
C
:
Stimulates fruit ripening
D
:
Breaks seed dormancy
99 : What is the main role of gibberellins in plants?
A
:
Inhibit cell division
B
:
Promote cell enlargement and seed germination
C
:
Delay leaf senescence
D
:
Promote flowering in short-day plants
100 : Where are cytokinins primarily produced in plants?
A
:
In leaves and flowers
B
:
In roots, young fruits, and seeds
C
:
In stems and leaves
D
:
In roots and flower petals
101 : Which of the following is the primary function of auxins in plants?
A
:
Inhibit cell division
B
:
Promote cell enlargement and growth in roots
C
:
Stimulate leaf senescence
D
:
Promote seed dormancy
102 : Why is spring wood lighter?
A
:
Wider vessels
B
:
More water availability
C
:
Denser vessels
D
:
More xylem cells
103 : How is dendrochronology used in climate studies?
A
:
By measuring tree age
B
:
By analyzing wood growth
C
:
By comparing roots
D
:
By counting fruit
104 : What happens if vascular cambium is damaged?
A
:
No height growth
B
:
No leaf production
C
:
No thickness growth
D
:
Loss of bark protection
105 : Why study growth in plants for agriculture?
A
:
To control plant height
B
:
To increase flower production
C
:
To strengthen stems
D
:
To improve crop yield and quality
106 : How does cambium affect wood production?
A
:
Creates annual rings
B
:
Increases root growth
C
:
Forms more branches
D
:
Increases leaf size
107 : How does vascular cambium aid in growth?
A
:
By forming cork cells
B
:
By making phloem and xylem
C
:
By producing leaves
D
:
By increasing height
108 : Which meristem forms the bark?
A
:
Apical meristem
B
:
Cork cambium
C
:
Vascular cambium
D
:
Intercalary meristem
109 : Why do cells in elongation zone become large?
A
:
For cell differentiation
B
:
For cell division
C
:
For plant expansion
D
:
For sugar storage
110 : Why is secondary growth important in woody plants?
A
:
More vascular cambium
B
:
Less intercalary meristem
C
:
No lateral meristems
D
:
No apical meristems
111 : How do annual rings help in determining tree age?
A
:
By counting branches
B
:
By observing wood growth
C
:
By counting rings
D
:
By measuring roots
112 : How does cohesion help in water movement?
A
:
It prevents leakage
B
:
It binds with xylem walls
C
:
It forms an unbroken water column
D
:
It stops transpiration
113 : Where are intercalary meristems found?
A
:
Root tip
B
:
Between two vascular tissues
C
:
Base of internodes
D
:
Outer stem layer
114 : What is the function of lateral meristems?
A
:
Length growth
B
:
Thickness growth
C
:
Leaf production
D
:
Flower formation
115 : What causes primary growth in plants?
A
:
Apical meristem
B
:
Lateral meristem
C
:
Vascular cambium
D
:
Cork cambium
116 : What do salt glands in hydrophytes do?
A
:
Absorb water
B
:
Store nutrients
C
:
Excrete salts
D
:
Promote growth
117 : Why are mesophytes important?
A
:
They control salinity
B
:
They support food webs
C
:
They prevent soil erosion
D
:
They increase water levels
118 : How do halophytes tolerate salinity?
A
:
Absorb less salt
B
:
Excrete excess salts
C
:
Grow faster
D
:
Reduce salt in soil
119 : How do xerophytes prevent water loss?
A
:
Water storage in stems
B
:
Large leaves
C
:
Shallow roots
D
:
Leaf shedding
120 : How do hydrophytes expel excess water?
A
:
Through roots
B
:
Through hydathodes
C
:
Through leaves
D
:
Through flowers
121 : How does a hypertonic solution affect plant cells?
A
:
Cell swells
B
:
Causes plasmolysis
C
:
No effect
D
:
Cell divides
122 : Why do halophytes have succulent leaves?
A
:
To store nutrients
B
:
To store water
C
:
To store sugars
D
:
To store salt
123 : How do xerophytes minimize water loss?
A
:
Large leaves for transpiration
B
:
Waxy coatings, reduced leaves
C
:
Deep root systems
D
:
Water absorption through leaves
124 : Why do hydrophytes expel excess water?
A
:
To store more water
B
:
To avoid overhydration
C
:
To absorb nutrients
D
:
To store salts
125 : Why is the pressure-flow theory important in plant transport?
A
:
It explains water transport in xylem
B
:
It explains sugar transport to roots
C
:
It helps nutrient absorption
D
:
It explains nutrient storage
126 : What is a hypertonic solution?
A
:
Low solute concentration
B
:
Equal solute concentration
C
:
High solute concentration, water leaves
D
:
No movement of water
127 : Which environment do hydrophytes thrive in?
A
:
Dry conditions
B
:
Saline conditions
C
:
Aquatic environments
D
:
Moderate conditions
128 : What is a hypotonic solution?
A
:
High solute concentration
B
:
Equal solute concentration
C
:
Low solute concentration, water enters
D
:
No effect on the cell
129 : What is osmoregulation in plants?
A
:
Temperature regulation
B
:
Water and salt balance
C
:
Photosynthesis regulation
D
:
Respiratory control
130 : How does chemotropism benefit plants in nutrient-rich environments?
A
:
By guiding roots to grow towards high oxygen areas
B
:
By enabling roots to grow towards chemical nutrients like nitrogen
C
:
By preventing the loss of water
D
:
By facilitating flower pollination
131 : Why do plants in temperate regions produce heat-shock proteins?
A
:
To increase photosynthesis rates
B
:
To protect enzymes from high temperatures
C
:
To improve water uptake
D
:
To prevent leaf loss
132 : How does osmotic regulation help plants cope with drought stress?
A
:
By maintaining high sugar content in leaves
B
:
By absorbing excess water from the soil
C
:
By synthesizing heat-shock proteins
D
:
By increasing solute concentration in cells to retain water
133 : Why is thigmotropism important for climbing plants like vines?
A
:
It allows them to grow towards light
B
:
It enables them to coil around supports for stability
C
:
It helps them absorb more water
D
:
It accelerates root development
134 : How do heat-shock proteins help pigments in heat-stressed environments?
A
:
By reducing water loss
B
:
By enhancing protein folding and stability
C
:
By increasing cell division
D
:
By promoting flower growth
135 : How do plants avoid damage from freezing temperatures?
A
:
By accumulating sugar in the cells
B
:
By forming ice crystals in the cell wall but not inside the cell
C
:
By reducing water content
D
:
By increasing transpiration rates
136 : Why is gradual chilling less stressful for plants compared to rapid chilling?
A
:
It allows plants to adapt and adjust their membrane structure
B
:
It promotes faster nutrient uptake
C
:
It prevents ice crystals from forming
D
:
It helps plants grow faster
137 : How do plants respond to cold stress?
A
:
By forming ice crystals within cells
B
:
By increasing the proportion of unsaturated fatty acids in the membrane
C
:
By synthesizing heat-shock proteins
D
:
By decreasing the number of stomata
138 : Why do plants synthesize heat-shock proteins during heat stress?
A
:
To increase the rate of photosynthesis
B
:
To prevent enzyme denaturation
C
:
To promote seed formation
D
:
To enhance nutrient absorption
139 : What is geotropism in plants?
A
:
Movement of plants in response to touch
B
:
Movement of plants in response to gravity
C
:
Movement of plants towards light
D
:
Growth towards chemicals
140 : What is phototropism in plants?
A
:
Movement in response to water
B
:
Movement towards light
C
:
Movement in response to touch
D
:
Movement in response to gravity
141 : What is the effect of low temperature on plant cell membranes?
A
:
Membranes become more flexible
B
:
Membranes freeze and break
C
:
Membranes become rigid due to crystalline structure
D
:
Membranes become impermeable to water
142 : How do plants cope with high temperatures?
A
:
By synthesizing heat-shock proteins
B
:
By increasing transpiration
C
:
By closing stomata
D
:
By expanding their leaves
143 : What is thermoregulation in plants?
A
:
Maintaining body temperature through water absorption
B
:
Maintaining body temperature despite environmental changes
C
:
Cooling the plant using sunlight
D
:
Increasing temperature to speed up growth
144 : Which pigment absorbs red light at 660 nm?
A
:
Chlorophyll
B
:
P660
C
:
P730
D
:
Xanthophyll
145 : Why is florigen important for flowering?
A
:
Inhibits root growth
B
:
Induces flowering
C
:
Stops photosynthesis
D
:
Initiates dormancy
146 : In which condition will henbane flower?
A
:
Long night
B
:
Interrupted night
C
:
Short night
D
:
No dark period
147 : Which plant flowers regardless of photoperiod?
A
:
Cucumber
B
:
Chrysanthemum
C
:
Wheat
D
:
Tomato
148 : Which of the following is a short-day plant?
A
:
Tomato
B
:
Henbane
C
:
Tobacco
D
:
Chrysanthemum
149 : What would likely happen if a short-day plant is exposed to red light during night?
A
:
It will flower early
B
:
It will not flower
C
:
No effect
D
:
Increases leaf growth
150 : Why is P730 considered a time regulator?
A
:
Converts into light energy
B
:
Controls oxygen release
C
:
Signals flowering condition
D
:
Converts florigen into sugar
151 : What controls the time measurement for flowering?
A
:
Florigen only
B
:
Phytochrome alone
C
:
Hormones and dark period
D
:
Water and nutrients
152 : How do long-day plants respond to night interruption?
A
:
No effect
B
:
Delay flowering
C
:
Promote flowering
D
:
Cause leaf fall
153 : Why does interrupting long night with light prevent flowering in SDPs?
A
:
Light increases P660
B
:
Darkness stops hormones
C
:
Light halts florigen transport
D
:
Red light converts P730
154 : What happens to P660 in daylight?
A
:
Converts to sugar
B
:
Becomes inactive
C
:
Converts to P730
D
:
Triggers cell division
155 : What pigment detects light changes in plants?
A
:
Auxin
B
:
Phytochrome
C
:
Florigen
D
:
Chlorophyll
156 : What triggers flowering in short-day plants?
A
:
Long day
B
:
Long nights
C
:
High temperature
D
:
Rainfall
157 : Who first studied photoperiodism?
A
:
Mendel and Darwin
B
:
Watson and Crick
C
:
Garner and Allard
D
:
Hooker and Allard
158 : What is photoperiodism in plants?
A
:
Growth due to water
B
:
Movement toward light
C
:
Response to temperature
D
:
Response to day/night length
159 : What results from secondary growth?
A
:
Length increase
B
:
Thickness increase
C
:
Leaf size increase
D
:
Root number increase
160 : What are mesophytes?
A
:
Plants for dry conditions
B
:
Plants for saline environments
C
:
Plants for moderate environments
D
:
Plants for aquatic environments
Biology 11th MCQs || Ilam Ghar
Chapter 8 : Plant Physiology
Biology 11th