Botany

Question : Which tissue in plants is primarily responsible for the increase in girth of stems and roots?
Vascular cambium
Apical meristem
Intercalary meristem
Protoderm
Correct Answer : Vascular cambium

Question : In a typical dicot root, the vascular bundles are arranged as:
Conjoint and collateral
Radial with exarch xylem
Conjoint and bicollateral
Radial with endarch xylem
Correct Answer : Radial with exarch xylem

Question : Which of the following is a characteristic feature of sclerenchymatous cells?
They are living and actively dividing
They possess thin primary walls
They have thick, lignified secondary walls
They contain abundant chloroplasts
Correct Answer : They have thick, lignified secondary walls

Question : The Casparian strips in the endodermis of roots are mainly composed of:
Cellulose
Suberin
Pectin
Lignin only
Correct Answer : Suberin

Question : Which of the following correctly represents the sequence of tissues encountered from the outside toward the centre in a typical dicot stem?
Epidermis → cortex → endodermis → pericycle → vascular bundles → pith
Epidermis → cortex → pericycle → endodermis → vascular bundles → pith
Epidermis → endodermis → cortex → pericycle → vascular bundles → pith
Epidermis → cortex → vascular bundles → endodermis → pericycle → pith
Correct Answer : Epidermis → cortex → endodermis → pericycle → vascular bundles → pith

Question : In a dorsiventral leaf, the palisade parenchyma is generally located:
Below the upper epidermis
Below the lower epidermis
Around the vascular bundles only
Between the epidermis and cuticle
Correct Answer : Below the upper epidermis

Question : Which plant hormone promotes cell division and delays senescence of leaves?
Auxin
Gibberellin
Cytokinin
Abscisic acid
Correct Answer : Cytokinin

Question : A plant cell placed in a hypertonic solution undergoes plasmolysis because:
Water enters the cell by endosmosis
Water leaves the cell by exosmosis
Solutes enter the cell by active transport
The cell wall loses its permeability
Correct Answer : Water leaves the cell by exosmosis

Question : Which statement about phloem transport is correct?
It occurs only from roots toward leaves
It is always unidirectional in a plant
Organic solutes can move from source to sink through sieve tubes
It occurs exclusively through xylem vessels
Correct Answer : Organic solutes can move from source to sink through sieve tubes

Question : If a plant is exposed to prolonged water stress, which response is most directly associated with abscisic acid?
Stomatal closure
Promotion of cell division
Breaking of seed dormancy
Increased transpiration
Correct Answer : Stomatal closure

Question : In C4 plants, the initial fixation of atmospheric CO₂ occurs in mesophyll cells, producing:
3-phosphoglyceric acid using RuBisCO
Oxaloacetic acid using PEP carboxylase
Ribulose bisphosphate using PEP carboxylase
Pyruvic acid using RuBisCO
Correct Answer : Oxaloacetic acid using PEP carboxylase

Question : Which of the following combinations is correctly matched?
Chlorophyll a — reaction centre pigment
Carotenoids — primary electron acceptors
RuBisCO — enzyme of glycolysis
Cytochrome oxidase — Calvin cycle enzyme
Correct Answer : Chlorophyll a — reaction centre pigment

Question : During photorespiration in a C3 plant, the initial oxygenation reaction involving RuBisCO results in the formation of:
Two molecules of 3-PGA
One molecule each of 3-PGA and 2-phosphoglycolate
Two molecules of phosphoglycolate
One molecule each of glucose and oxygen
Correct Answer : One molecule each of 3-PGA and 2-phosphoglycolate

Question : Which stage of cellular respiration produces the largest amount of ATP under aerobic conditions?
Glycolysis
Krebs cycle
Oxidative phosphorylation
Fermentation
Correct Answer : Oxidative phosphorylation

Question : A plant has a net gain of 6 molecules of CO₂ fixed through the Calvin cycle. The number of molecules of 3-phosphoglycerate initially formed is:
6
12
18
24
Correct Answer : 12

Question : Which of the following statements about cyclic photophosphorylation is correct?
It involves both photosystems I and II
It results in the photolysis of water
It produces ATP but not NADPH
It produces NADPH but not ATP
Correct Answer : It produces ATP but not NADPH

Question : In the Krebs cycle, substrate-level phosphorylation directly results in the formation of:
ATP or GTP
NADPH
FADH₂ only
Oxygen
Correct Answer : ATP or GTP

Question : Which of the following is an example of a plant showing heterophylly?
Presence of different leaf forms at different stages or conditions
Presence of only compound leaves
Development of leaves exclusively underground
Formation of leaves only during flowering
Correct Answer : Presence of different leaf forms at different stages or conditions

Question : The main function of the root cap is to:
Absorb mineral salts
Protect the root apical meristem
Transport food to the root
Increase the rate of photosynthesis
Correct Answer : Protect the root apical meristem

Question : Which Mendelian ratio is expected in the F₂ generation of a typical dihybrid cross involving two independently assorting genes with complete dominance?
3 : 1
1 : 1
9 : 3 : 3 : 1
1 : 2 : 1
Correct Answer : 9 : 3 : 3 : 1

Question : Which meristem is responsible for the formation of primary tissues in a plant body?
Lateral meristem
Apical meristem
Cork cambium
Vascular cambium
Correct Answer : Apical meristem

Question : In a monocot stem, vascular bundles are generally:
Arranged in a ring and open
Scattered and closed
Arranged in a ring and closed
Scattered and open
Correct Answer : Scattered and closed

Question : Which of the following is a simple permanent tissue?
Xylem
Phloem
Parenchyma
Epidermis
Correct Answer : Parenchyma

Question : Companion cells are associated with:
Tracheids
Vessels
Sieve tube elements
Fibres
Correct Answer : Sieve tube elements

Question : Which component of xylem is mainly responsible for conduction of water and minerals?
Fibres
Parenchyma
Vessels and tracheids
Companion cells
Correct Answer : Vessels and tracheids

Question : Bulliform cells are characteristically found in the:
Lower epidermis of dicot leaves
Upper epidermis of grasses
Pericycle of roots
Cortex of dicot stems
Correct Answer : Upper epidermis of grasses

Question : Which of the following is a xerophytic adaptation that helps reduce water loss?
Large thin leaves
Sunken stomata
Absence of cuticle
Reduced root system
Correct Answer : Sunken stomata

Question : The movement of water through the apoplast pathway occurs mainly through:
Cytoplasm of living cells
Cell walls and intercellular spaces
Plasmodesmata
Vacuoles
Correct Answer : Cell walls and intercellular spaces

Question : Which force is primarily responsible for the ascent of sap in tall trees according to the cohesion-tension theory?
Root pressure alone
Transpiration pull
Osmotic pressure of phloem
Active pumping by xylem cells
Correct Answer : Transpiration pull

Question : Guttation commonly occurs through specialized structures called:
Lenticels
Hydathodes
Stomata
Trichomes
Correct Answer : Hydathodes

Question : Which plant growth regulator is most closely associated with fruit ripening?
Auxin
Ethylene
Cytokinin
Abscisic acid
Correct Answer : Ethylene

Question : Gibberellins are known to promote:
Stomatal closure
Bolting and internode elongation
Leaf senescence
Fruit ripening exclusively
Correct Answer : Bolting and internode elongation

Question : Which hormone is commonly associated with breaking seed dormancy and promoting germination?
Abscisic acid
Gibberellin
Ethylene
Cytokinin
Correct Answer : Gibberellin

Question : Apical dominance in plants is primarily promoted by:
Auxin
Ethylene
Abscisic acid
Cytokinin
Correct Answer : Auxin

Question : Which of the following is an example of a short-day plant?
Wheat
Spinach
Rice
Pea
Correct Answer : Rice

Question : Photoperiodism refers to the response of plants to:
Intensity of light only
Duration of light and dark periods
Direction of light
Quality of soil
Correct Answer : Duration of light and dark periods

Question : The respiratory quotient for carbohydrates under aerobic conditions is generally:
0.5
1.0
1.5
2.0
Correct Answer : 1.0

Question : During glycolysis, one molecule of glucose is converted into:
Two molecules of pyruvate
Two molecules of acetyl-CoA
One molecule of pyruvate
Four molecules of pyruvate
Correct Answer : Two molecules of pyruvate

Question : In aerobic respiration, pyruvate is converted into acetyl-CoA in the:
Cytoplasm
Mitochondrial matrix
Inner mitochondrial membrane
Chloroplast
Correct Answer : Mitochondrial matrix

Question : Which molecule acts as the primary CO₂ acceptor in the Calvin cycle?
PEP
RuBP
OAA
PGA
Correct Answer : RuBP

Question : The enzyme RuBisCO is located in the:
Thylakoid lumen
Stroma of chloroplast
Outer mitochondrial membrane
Cytoplasm
Correct Answer : Stroma of chloroplast

Question : In the light reaction of photosynthesis, photolysis of water is associated with:
Photosystem I
Photosystem II
Cytochrome complex only
ATP synthase
Correct Answer : Photosystem II

Question : The oxygen released during photosynthesis comes from:
Carbon dioxide
Glucose
Water
RuBP
Correct Answer : Water

Question : Which of the following molecules is directly required for the reduction phase of the Calvin cycle?
NADPH
FAD
O₂
N₂
Correct Answer : NADPH

Question : In a C4 plant, the bundle sheath cells are generally characterized by:
Absence of chloroplasts
Large chloroplasts and little intercellular space
Complete absence of mitochondria
Absence of cell walls
Correct Answer : Large chloroplasts and little intercellular space

Question : Which of the following is a characteristic feature of CAM plants?
Stomata remain open throughout the day
CO₂ is fixed at night and utilized during the day
They lack chlorophyll
They perform only anaerobic respiration
Correct Answer : CO₂ is fixed at night and utilized during the day

Question : In CAM plants, organic acids accumulated during the night are primarily stored in:
Chloroplasts
Vacuoles
Nucleus
Mitochondria
Correct Answer : Vacuoles

Question : Which mineral element is a component of the chlorophyll molecule?
Nitrogen
Magnesium
Potassium
Calcium
Correct Answer : Magnesium

Question : Nitrogen deficiency in plants commonly causes:
Chlorosis of older leaves
Increased chlorophyll synthesis
Enhanced root pressure
Immediate fruit ripening
Correct Answer : Chlorosis of older leaves

Question : Which microorganism is commonly associated with biological nitrogen fixation in leguminous plants?
Rhizobium
Azotobacter only
Nitrosomonas
Pseudomonas
Correct Answer : Rhizobium

Question : Nitrification involves the conversion of:
Nitrate into atmospheric nitrogen
Ammonia into nitrite and then nitrate
Nitrogen gas into ammonia directly by plants
Proteins directly into nitrogen gas
Correct Answer : Ammonia into nitrite and then nitrate

Question : Which of the following is an essential macronutrient for plants?
Molybdenum
Boron
Zinc
Phosphorus
Correct Answer : Phosphorus

Question : The opening and closing of stomata are directly regulated by changes in:
Guard cell turgor
Xylem lignification
Root cap thickness
Phloem fibre length
Correct Answer : Guard cell turgor

Question : During stomatal opening, potassium ions generally:
Move out of guard cells
Accumulate in guard cells
Are converted into glucose
Enter the xylem vessels directly
Correct Answer : Accumulate in guard cells

Question : Which type of cell division produces genetically identical daughter cells and maintains chromosome number?
Meiosis I
Meiosis II
Mitosis
Reduction division
Correct Answer : Mitosis

Question : In flowering plants, meiosis in the microspore mother cell produces:
Two diploid microspores
Four haploid microspores
Four diploid pollen grains
One haploid megaspore
Correct Answer : Four haploid microspores

Question : The functional megaspore in a typical angiosperm develops into:
Endosperm
Embryo sac
Pollen grain
Seed coat
Correct Answer : Embryo sac

Question : A typical mature embryo sac of an angiosperm contains:
Eight cells and seven nuclei
Seven cells and eight nuclei
Eight cells and eight nuclei
Seven cells and seven nuclei
Correct Answer : Seven cells and eight nuclei

Question : Double fertilisation in angiosperms involves:
Syngamy and triple fusion
Two successive syngamy events
Triple fusion only
Pollination and syngamy
Correct Answer : Syngamy and triple fusion

Question : The endosperm formed after triple fusion in a typical angiosperm is initially:
Haploid
Diploid
Triploid
Tetraploid
Correct Answer : Triploid

Question : Which part of the root is mainly responsible for the absorption of water and minerals from the soil?
Root cap
Region of meristematic activity
Region of elongation
Region of maturation
Correct Answer : Region of maturation

Question : In a typical dicot stem, the vascular bundles are described as:
Radial and exarch
Conjoint, collateral and open
Conjoint, bicollateral and closed
Radial and endarch
Correct Answer : Conjoint, collateral and open

Question : Which tissue provides mechanical strength to young growing plant parts?
Parenchyma
Collenchyma
Chlorenchyma
Aerenchyma
Correct Answer : Collenchyma

Question : Which of the following xylem elements is living at maturity?
Vessel
Tracheid
Xylem fibre
Xylem parenchyma
Correct Answer : Xylem parenchyma

Question : The secondary growth in dicot roots is mainly brought about by the activity of:
Apical meristem and protoderm
Vascular cambium and cork cambium
Intercalary meristem and phellogen
Pericycle and epidermis only
Correct Answer : Vascular cambium and cork cambium

Question : Which tissue forms the protective outer covering of young plant organs?
Epidermis
Phloem
Endodermis
Pericycle
Correct Answer : Epidermis

Question : Lenticels are primarily involved in:
Translocation of food
Gaseous exchange
Absorption of minerals
Secondary thickening of roots
Correct Answer : Gaseous exchange

Question : Which of the following is correctly matched with its function?
Xylem — transport of organic food
Phloem — transport of organic solutes
Collenchyma — conduction of water
Sclerenchyma — photosynthesis
Correct Answer : Phloem — transport of organic solutes

Question : If a plant cell has a solute potential of −0.8 MPa and a pressure potential of +0.3 MPa, its water potential is:
−1.1 MPa
−0.5 MPa
+0.5 MPa
+1.1 MPa
Correct Answer : −0.5 MPa

Question : Root pressure is most likely to be observed when:
Transpiration is extremely high
Soil is dry
Transpiration is low and soil water is readily available
Stomata remain permanently open
Correct Answer : Transpiration is low and soil water is readily available

Question : Which phenomenon explains the movement of water molecules through a selectively permeable membrane from higher water potential to lower water potential?
Diffusion
Osmosis
Active transport
Imbibition
Correct Answer : Osmosis

Question : Which statement about transpiration is correct?
It occurs only through stomata
It helps in the ascent of water through the xylem
It always decreases mineral absorption
It occurs only during darkness
Correct Answer : It helps in the ascent of water through the xylem

Question : The proton gradient required for ATP synthesis during photosynthesis is established across the:
Outer chloroplast membrane
Thylakoid membrane
Inner mitochondrial membrane
Nuclear membrane
Correct Answer : Thylakoid membrane

Question : In non-cyclic photophosphorylation, the final electron acceptor is:
Water
Oxygen
NADP⁺
RuBP
Correct Answer : NADP⁺

Question : Which of the following correctly describes the Z-scheme of photosynthetic electron transport?
Electrons move from Photosystem I to water only
Electrons are excited twice during non-cyclic electron flow
Only Photosystem II participates
ATP is formed without electron transport
Correct Answer : Electrons are excited twice during non-cyclic electron flow

Question : If a C3 plant and a C4 plant are exposed to high temperature and intense light, the C4 plant generally shows greater photosynthetic efficiency because it:
Lacks chloroplasts in mesophyll cells
Has a mechanism that concentrates CO₂ around RuBisCO
Uses oxygen as the primary carbon source
Does not require ATP during carbon fixation
Correct Answer : Has a mechanism that concentrates CO₂ around RuBisCO

Question : Which compound is regenerated at the end of the Calvin cycle?
3-phosphoglycerate
Triose phosphate
RuBP
Oxaloacetate
Correct Answer : RuBP

Question : For the fixation of 3 molecules of CO₂ in the Calvin cycle, the number of turns of the cycle required is:
1
2
3
6
Correct Answer : 3

Question : Which of the following is an amphibolic pathway?
Glycolysis
Krebs cycle
Fermentation
Photophosphorylation
Correct Answer : Krebs cycle

Question : Under anaerobic conditions in yeast, pyruvate is converted into:
Lactate only
Ethanol and CO₂
Acetyl-CoA and CO₂
Oxaloacetate and CO₂
Correct Answer : Ethanol and CO₂

Question : During glycolysis, the net gain from one molecule of glucose is:
2 ATP and 2 NADH
4 ATP and 4 NADH
2 ATP and 4 NADH
4 ATP and 2 FADH₂
Correct Answer : 2 ATP and 2 NADH

Question : Which molecule enters the Krebs cycle after oxidative decarboxylation of pyruvate?
Pyruvate
Acetyl-CoA
Oxaloacetate
Lactate
Correct Answer : Acetyl-CoA

Question : The respiratory quotient of an organism utilizing fats as the major respiratory substrate is generally:
Equal to 1
Greater than 1
Less than 1
Always zero
Correct Answer : Less than 1

Question : Which plant growth regulator is associated with stress responses and induction of seed dormancy?
Auxin
Cytokinin
Abscisic acid
Gibberellin
Correct Answer : Abscisic acid

Question : Which hormone is widely used to induce rooting in stem cuttings?
Auxin
Ethylene
Abscisic acid
Cytokinin
Correct Answer : Auxin

Question : Which of the following effects is associated with ethylene?
Promotion of apical dominance
Fruit ripening
Stimulation of cell division in roots
Inhibition of abscission
Correct Answer : Fruit ripening

Question : A plant hormone is applied to a rosette plant and causes rapid elongation of the internodes, resulting in bolting. The hormone is most likely:
Gibberellin
Cytokinin
Abscisic acid
Ethylene
Correct Answer : Gibberellin

Question : The phenomenon in which a plant responds to the relative duration of day and night to initiate flowering is:
Vernalisation
Phototropism
Photoperiodism
Geotropism
Correct Answer : Photoperiodism

Question : Vernalisation is particularly useful in promoting flowering in certain plants by exposure to:
High temperature
Low temperature
Continuous darkness
High salinity
Correct Answer : Low temperature

Question : Which of the following is a major function of cytokinins?
Promotion of cell division
Induction of stomatal closure
Promotion of fruit ripening
Inhibition of cell division
Correct Answer : Promotion of cell division

Question : In a typical angiosperm pollen grain, the generative cell ultimately gives rise to:
One egg cell
Two male gametes
Two synergids
Three antipodal cells
Correct Answer : Two male gametes

Question : Which layer of the anther wall helps in the dehiscence of the anther at maturity?
Epidermis
Endothecium
Middle layers
Tapetum
Correct Answer : Endothecium

Question : The tapetum of the anther is mainly concerned with:
Protection of the ovule
Nutrition of developing pollen grains
Formation of the seed coat
Formation of the embryo
Correct Answer : Nutrition of developing pollen grains

Question : In an angiosperm, the pollen tube usually enters the ovule through the:
Chalaza
Micropyle
Funicle
Integument
Correct Answer : Micropyle

Question : Which cells of the mature embryo sac are located at the micropylar end?
Three antipodals
Two polar nuclei
Egg apparatus
Central cell only
Correct Answer : Egg apparatus

Question : The two polar nuclei present in the central cell of a typical embryo sac are formed by:
Fusion of the two synergids
Fusion of the three antipodals
Fusion of the two polar nuclei after their migration
Division of the egg cell
Correct Answer : Fusion of the two polar nuclei after their migration

Question : Apomixis is best described as:
Formation of fruits without fertilisation
Formation of seeds without fertilisation
Fusion of two male gametes
Development of pollen grains without meiosis
Correct Answer : Formation of seeds without fertilisation

Question : Polyembryony refers to the occurrence of:
More than one embryo in a seed
More than one seed in a fruit
More than one pollen grain in an anther
More than one ovule in an ovary
Correct Answer : More than one embryo in a seed

Question : Which part of a typical dicot seed develops into the seed coat?
Endosperm
Integuments
Nucellus
Embryo
Correct Answer : Integuments

Question : In a monocot seed such as maize, the single cotyledon is called:
Scutellum
Coleoptile
Coleorhiza
Pericarp
Correct Answer : Scutellum

Question : During seed germination, the first structure to emerge from a typical seed is generally the:
Plumule
Radicle
Cotyledon
Hypocotyl
Correct Answer : Radicle

Question : Which of the following is a characteristic feature of meristematic cells?
Large central vacuole
Dense cytoplasm and prominent nucleus
Extensive intercellular spaces
Dead protoplasm
Correct Answer : Dense cytoplasm and prominent nucleus

Question : In a typical monocot root, the number of xylem poles is generally:
Two
Three
Four
More than six
Correct Answer : More than six

Question : Which tissue is responsible for the conduction of organic food in plants?
Xylem
Phloem
Collenchyma
Sclerenchyma
Correct Answer : Phloem

Question : Which of the following is NOT a component of the vascular tissue system?
Xylem
Phloem
Pericycle
Companion cells
Correct Answer : Pericycle

Question : The vascular bundles of a typical monocot stem are:
Open because cambium is present
Closed because cambium is absent
Radial because xylem and phloem alternate
Bicollateral because two cambial strips are present
Correct Answer : Closed because cambium is absent

Question : In a dicot leaf, the vascular bundles are generally surrounded by:
Bundle sheath
Endodermis
Pericycle
Cork
Correct Answer : Bundle sheath

Question : Which modification of roots provides additional support to the stem in maize?
Prop roots
Pneumatophores
Storage roots
Tuberous roots
Correct Answer : Prop roots

Question : Pneumatophores are specialized roots commonly found in plants growing in:
Deserts
Marshy and waterlogged areas
Mountain regions
Freshwater lakes only
Correct Answer : Marshy and waterlogged areas

Question : The tendrils of pea are modifications of:
Roots
Leaves
Stems
Inflorescences
Correct Answer : Leaves

Question : The thorn of Bougainvillea is a modification of:
Leaf
Root
Stem
Stipule
Correct Answer : Stem

Question : Which type of venation is typically found in monocot leaves?
Reticulate
Parallel
Dichotomous
Furcate
Correct Answer : Parallel

Question : In an isobilateral leaf, stomata are generally present:
Only on the upper surface
Only on the lower surface
On both surfaces
Only along the midrib
Correct Answer : On both surfaces

Question : Which of the following is a correct example of a simple leaf?
Neem
Pea
Guava
Acacia
Correct Answer : Guava

Question : In a compound leaf, the axillary bud is present:
At the base of every leaflet
In the axil of the whole leaf
At the tip of every leaflet
Only on the petiole of each leaflet
Correct Answer : In the axil of the whole leaf

Question : Which floral whorl is directly involved in the production of pollen grains?
Calyx
Corolla
Androecium
Gynoecium
Correct Answer : Androecium

Question : A flower having both stamens and carpels is called:
Unisexual
Bisexual
Neuter
Asexual
Correct Answer : Bisexual

Question : A flower in which the gynoecium occupies the highest position while other floral parts are below it is:
Hypogynous
Perigynous
Epigynous
Zygomorphic
Correct Answer : Hypogynous

Question : Which placentation is characteristic of tomato?
Marginal
Axile
Parietal
Basal
Correct Answer : Axile

Question : In marginal placentation, the ovules are borne:
On the central axis
Along the ventral suture of a single carpel
On the inner wall of a multilocular ovary
At the base of the ovary
Correct Answer : Along the ventral suture of a single carpel

Question : Which of the following represents a valvate aestivation?
Petals overlap one another regularly
One margin overlaps the next and so on
Margins of adjacent petals touch but do not overlap
Two petals completely enclose the remaining petals
Correct Answer : Margins of adjacent petals touch but do not overlap

Question : Which part of the flower develops into the fruit after fertilisation?
Ovule
Ovary
Anther
Stigma
Correct Answer : Ovary

Question : Which part of the ovule develops into the seed coat?
Nucellus
Integuments
Embryo sac
Funicle
Correct Answer : Integuments

Question : In most angiosperms, the endosperm develops before:
Pollination
Fertilisation
Embryo development
Formation of pollen grains
Correct Answer : Embryo development

Question : Which of the following is a characteristic feature of a dicot embryo?
One cotyledon
Two cotyledons
No plumule
Absence of radicle
Correct Answer : Two cotyledons

Question : During germination of a hypogeal seed, the cotyledons:
Are carried above the soil surface
Remain below the soil surface
Always become photosynthetic leaves
Develop directly into roots
Correct Answer : Remain below the soil surface

Question : Which process involves the movement of pollen grains from the anther to the stigma of the same flower?
Cross-pollination
Self-pollination
Fertilisation
Apomixis
Correct Answer : Self-pollination

Question : Which adaptation is commonly associated with wind-pollinated flowers?
Large and brightly coloured petals
Production of abundant lightweight pollen
Strong fragrance and nectar
Sticky pollen grains
Correct Answer : Production of abundant lightweight pollen

Question : The phenomenon in which pollen grains of the same species are transferred from one flower to another flower is:
Autogamy
Geitonogamy
Apomixis
Parthenocarpy
Correct Answer : Geitonogamy

Question : Which of the following is an outbreeding device that prevents self-pollination by maturation of anthers and stigma at different times?
Herkogamy
Dichogamy
Self-incompatibility
Monoecy
Correct Answer : Dichogamy

Question : Fusion of one male gamete with the egg cell results in the formation of:
Endosperm
Zygote
Primary endosperm cell
Pollen tube
Correct Answer : Zygote

Question : If the chromosome number of the egg cell is 10, the chromosome number of the primary endosperm nucleus after triple fusion will be:
10
20
30
40
Correct Answer : 30

Question : Which of the following correctly describes triple fusion?
Fusion of two eggs with one male gamete
Fusion of one male gamete with two polar nuclei
Fusion of two male gametes with the egg
Fusion of two synergids with one male gamete
Correct Answer : Fusion of one male gamete with two polar nuclei

Question : Which of the following is an example of a non-endospermic seed at maturity?
Castor
Maize
Pea
Coconut
Correct Answer : Pea

Question : The persistent nucellus found in some seeds is known as:
Perisperm
Pericarp
Testa
Tegmen
Correct Answer : Perisperm

Question : Which of the following is an example of a parthenocarpic fruit?
Seedless banana
Mango
Pea
Gram
Correct Answer : Seedless banana

Question : In tissue culture, the ability of a single plant cell to develop into a complete plant is called:
Plasticity
Totipotency
Ploidy
Heterosis
Correct Answer : Totipotency

Question : Which technique is most directly used for rapid multiplication of genetically identical plants under sterile conditions?
Hybridisation
Micropropagation
Mutation breeding
Cross-pollination
Correct Answer : Micropropagation

Question : In plant breeding, emasculation is performed primarily to:
Remove immature ovules
Prevent unwanted self-pollination
Increase seed dormancy
Induce polyploidy
Correct Answer : Prevent unwanted self-pollination

Question : Which of the following is an example of a biofertiliser?
Rhizobium
Penicillium
Yeast
Agaricus
Correct Answer : Rhizobium

Question : Mycorrhiza represents a symbiotic association between:
Algae and fungi
Fungi and roots
Bacteria and leaves
Viruses and roots
Correct Answer : Fungi and roots

Question : Which of the following is the correct sequence of zones in a root from the root cap toward the mature region?
Zone of maturation → zone of elongation → zone of cell division
Zone of cell division → zone of elongation → zone of maturation
Zone of elongation → zone of maturation → zone of cell division
Zone of maturation → zone of cell division → zone of elongation
Correct Answer : Zone of cell division → zone of elongation → zone of maturation

Question : Which type of meristem is present at the bases of internodes in grasses and enables regrowth after grazing?
Apical meristem
Lateral meristem
Intercalary meristem
Secondary meristem
Correct Answer : Intercalary meristem

Question : Which of the following is a characteristic feature of heartwood?
It is actively involved in water conduction
It is lighter in colour than sapwood
It consists of older, non-functional secondary xylem
It contains abundant living xylem parenchyma
Correct Answer : It consists of older, non-functional secondary xylem

Question : During secondary growth, cork cambium produces:
Secondary xylem inward and secondary phloem outward
Phellem outward and phelloderm inward
Phelloderm outward and phellem inward
Only secondary phloem
Correct Answer : Phellem outward and phelloderm inward

Question : Which of the following statements about stomata is correct?
Guard cells of dicots are generally dumbbell-shaped
Guard cells of grasses are generally kidney-shaped
Guard cells regulate the opening and closing of stomata
Stomata are present only on roots
Correct Answer : Guard cells regulate the opening and closing of stomata

Question : The cohesion between water molecules is mainly due to:
Ionic bonds
Hydrogen bonds
Peptide bonds
Glycosidic bonds
Correct Answer : Hydrogen bonds

Question : Which factor directly decreases the rate of transpiration?
High temperature
High wind velocity
High atmospheric humidity
Low atmospheric humidity
Correct Answer : High atmospheric humidity

Question : Which of the following is a correct distinction between diffusion and active transport?
Diffusion always requires ATP
Active transport occurs only through cell walls
Diffusion occurs down a concentration gradient, whereas active transport can occur against it
Active transport never involves membrane proteins
Correct Answer : Diffusion occurs down a concentration gradient, whereas active transport can occur against it

Question : The first stable product formed during CO₂ fixation in a C4 plant is:
3-phosphoglycerate
Oxaloacetic acid
RuBP
Glucose
Correct Answer : Oxaloacetic acid

Question : Which of the following combinations correctly represents the products of the light-dependent reactions of photosynthesis?
ATP, NADPH and O₂
Glucose, ATP and CO₂
NADP⁺, ADP and O₂
RuBP, NADPH and CO₂
Correct Answer : ATP, NADPH and O₂

Question : If a plant is supplied with radioactive carbon dioxide containing ¹⁴C, the label would first appear in the products of:
Photolysis of water
Carbon fixation
Photophosphorylation
Electron transport
Correct Answer : Carbon fixation

Question : Which of the following statements about photorespiration is correct?
It is highest in C4 plants
It involves chloroplasts, peroxisomes and mitochondria
It produces large amounts of ATP
It occurs only in complete darkness
Correct Answer : It involves chloroplasts, peroxisomes and mitochondria

Question : In mitochondrial oxidative phosphorylation, ATP synthase uses:
A proton gradient
A sodium gradient only
A glucose gradient
An oxygen gradient
Correct Answer : A proton gradient

Question : Which of the following produces carbon dioxide during aerobic respiration?
Glycolysis
Oxidative phosphorylation
Pyruvate oxidation and Krebs cycle
Photophosphorylation
Correct Answer : Pyruvate oxidation and Krebs cycle

Question : If the oxygen supply to a respiring plant cell is suddenly stopped, which process can continue for a short period to generate ATP?
Krebs cycle
Electron transport chain
Glycolysis
Oxidative decarboxylation
Correct Answer : Glycolysis

Question : Which plant hormone is primarily responsible for maintaining apical dominance?
Cytokinin
Auxin
Ethylene
Abscisic acid
Correct Answer : Auxin

Question : A farmer wants to induce seedless fruits without fertilisation. Which phenomenon is most relevant?
Vernalisation
Parthenocarpy
Photoperiodism
Apomixis
Correct Answer : Parthenocarpy

Question : Which plant growth regulator is commonly used to overcome apical dominance and promote lateral bud growth?
Auxin
Cytokinin
Abscisic acid
Ethylene
Correct Answer : Cytokinin

Question : A plant is exposed to a day length that is shorter than its critical photoperiod and flowers only under these conditions. It is most likely a:
Long-day plant
Short-day plant
Day-neutral plant
Long-night insensitive plant
Correct Answer : Short-day plant

Question : Which of the following is an example of a day-neutral plant?
Wheat
Soybean
Tomato
Rice
Correct Answer : Tomato

Question : In a typical angiosperm, the microspore mother cell is:
Haploid
Diploid
Triploid
Tetraploid
Correct Answer : Diploid

Question : Which structure of the pollen grain gives rise to the pollen tube?
Generative cell
Vegetative cell
Endothecium
Tapetum
Correct Answer : Vegetative cell

Question : Self-incompatibility in flowering plants is a mechanism that:
Promotes self-fertilisation
Prevents genetically similar pollen from effecting fertilisation
Prevents formation of pollen grains
Causes seed dormancy
Correct Answer : Prevents genetically similar pollen from effecting fertilisation

Question : Which of the following is NOT a component of the egg apparatus in a typical embryo sac?
Egg cell
Two synergids
Three antipodals
None of the above
Correct Answer : Three antipodals

Question : The ploidy of the cells in the endosperm of a typical angiosperm is:
Haploid
Diploid
Triploid
Tetraploid
Correct Answer : Triploid

Question : Which of the following structures protects the plumule in a monocot embryo?
Coleorhiza
Scutellum
Coleoptile
Endosperm
Correct Answer : Coleoptile

Question : Which of the following is correctly matched?
Perisperm — persistent nucellus
Testa — inner integument only
Scutellum — root cap
Coleoptile — protects radicle
Correct Answer : Perisperm — persistent nucellus

Question : In apomixis, progeny are generally genetically similar to the parent because:
Meiosis is always followed by cross-fertilisation
Seed formation occurs without normal fertilisation
Two genetically unrelated gametes fuse
Only pollen grains undergo mutation
Correct Answer : Seed formation occurs without normal fertilisation

Question : Which of the following is an important advantage of micropropagation?
Production of genetically variable plants only
Rapid multiplication of disease-free plants
Prevention of all mutations
Elimination of photosynthesis
Correct Answer : Rapid multiplication of disease-free plants

Question : A plant breeder removes the anthers from a bisexual flower before they release pollen and then applies pollen from a selected plant. This procedure is:
Bagging only
Emasculation followed by artificial pollination
Apomixis
Vegetative propagation
Correct Answer : Emasculation followed by artificial pollination