Plant Growth and Development
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Growth regulators (Auxin, Gibberellin, Cytokinin, Ethylene, ABA)
SubtopicGrowth regulators (Auxin, Gibberellin, Cytokinin, Ethylene, ABA) under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
The phenomenon where ethylene breaks seed and bud dormancy is commonly seen in:
A.Cereal grains
B.Peanut seeds
C.Conifers
D.Tomato seeds
- 2.
Which PGR is known for increasing the shelf life of vegetables by delaying senescence?
A.Auxin
B.Gibberellin
C.Cytokinin
D.Ethylene
- 3.
Auxins are primarily produced in which part of the plant?
A.Roots and mature leaves
B.Growing apices of stems and roots
C.Flowers and seeds
D.Xylem and Phloem
- 4.
Which hormone is synthetic and used to prevent pre-harvest fruit drop in apples?
A.IBA
B.NAA
C.GA3
D.ABA
- 5.
The 'Triple Response' is a characteristic growth pattern observed in dicot seedlings and is commonly used as a bioassay for a specific plant growth regulator (PGR). Based on the effects shown in the flowchart, identify the PGR and the primary chemical precursor from which it is biosynthesized in plant tissues.
A.Auxin; Tryptophan
B.Gibberellin; Mevalonic acid
C.Ethylene; Methionine
D.Abscisic acid; Carotenoids
- 6.
Which of the following plant growth regulators was initially named 'Inhibitor-B', 'Abscission II', and 'Dormin' before its chemical identity was established?
A.Ethylene
B.Auxin
C.Abscisic acid
D.Gibberellin
- 7.
The synthesis of Ethylene takes place in almost all parts of the plant, but its highest concentration is found in:
A.Developing seeds
B.Ripening fruits and senescing tissues
C.Root tips
D.Young leaves
- 8.
In certain plant species, such as the mangrove , seeds exhibit 'vivipary', a condition where the embryo germinates while the seed is still attached to the parent plant. From a hormonal perspective, which physiological anomaly is most likely responsible for this deviation from the standard seed maturation process?
A.A significant deficiency in Abscisic Acid () levels or a reduced sensitivity of the embryo to signals.
B.A sudden surge in the synthesis of Ethylene within the pericarp, leading to enzymatic degradation of the seed coat.
C.The excessive transport of Cytokinins from the root system of the parent plant to the developing embryo.
D.The antagonistic suppression of Gibberellic Acid () by high concentrations of maternal Auxins.
- 9.
Which of the following hormones is associated with the 'stress' response and acts as a general plant growth inhibitor?
A.Abscisic Acid
B.Gibberellin
C.Cytokinin
D.Auxin
- 10.
Which hormone is responsible for breaking seed and bud dormancy in several plant species?
A.Gibberellin
B.Abscisic Acid
C.Auxin
D.Zeatin
Download the worksheet for Plant Growth and Development - Growth regulators (Auxin, Gibberellin, Cytokinin, Ethylene, ABA) to practice offline. It includes additional chapter-level practice questions.
Seed germination
SubtopicSeed germination under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
The primary objective of seed dormancy is to:
A.Prevent the plant from growing ever
B.Ensure germination occurs only under favorable environmental conditions
C.Reduce the nutritional value of the seed
D.Make the seed heavier
- 2.
Which part of the seed acts as a conduit for water entry during the initial stages of germination?
A.Hilum
B.Micropyle
C.Chalaza
D.Raphe
- 3.
What does a 'viable' seed mean?
A.A seed that is dead
B.A seed capable of germinating under suitable conditions
C.A seed without an embryo
D.A seed that has already germinated
- 4.
The portion of the embryonic axis between the radicle and the attachment point of cotyledons is the:
A.Epicotyl
B.Hypocotyl
C.Coleoptile
D.Hilum
- 5.
The elongation of the 'mesocotyl' is a specific feature seen during the germination of which type of plants?
A.Dicots like Bean
B.Monocots like Maize
C.Gymnosperms like Cycas
D.Pteridophytes
- 6.
Seeds of Xanthium (Cocklebur) show a peculiar dormancy where one seed of the fruit germinates in the first year and the other in the second year. This is primarily due to:
A.Different embryo maturity
B.Difference in seed coat permeability to oxygen
C.Light requirement
D.Presence of different hormones
- 7.
In many seeds, the onset of germination is marked by a sudden increase in the rate of oxygen consumption. This is called:
A.Respiratory burst
B.Climacteric rise
C.Imbibitional chilling
D.Photorespiration
- 8.
Why is the germination of seeds like those of Orchids considered unique or difficult compared to common crop seeds?
A.They have an extremely thick and stony testa
B.They lack significant nutrient reserves and require a symbiotic fungal partner (mycorrhiza) to germinate
C.They only germinate in the absence of water
D.They contain very high concentrations of cyanide
- 9.
The 'apical hook' in dicot seedlings is crucial for protecting the delicate shoot apical meristem during soil penetration. Which two hormones interact antagonistically to control the differential growth on the inner and outer sides of the hook?
A.Auxin and Ethylene
B.GA and ABA
C.Cytokinin and GA
D.Auxin and Cytokinin
- 10.
In the context of seed longevity, the 'Universal Rule of Thumb' states that for every 1% decrease in seed moisture content (within a certain range), the life of the seed:
A.Is halved
B.Is doubled
C.Remains the same
D.Decreases by 10 days
Download the worksheet for Plant Growth and Development - Seed germination to practice offline. It includes additional chapter-level practice questions.
Photoperiodism
SubtopicPhotoperiodism under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
In the context of photoperiodism, what does the term 'LDP' stand for?
A.Low Density Plant
B.Long Duration Plant
C.Long-Day Plant
D.Leaf Development Process
- 2.
Which of the following is NOT required for a Day-Neutral Plant to flower?
A.Nutrients
B.Water
C.A specific duration of light
D.Optimal temperature
- 3.
What is the primary site that perceives the stimulus of light duration?
A.Shoot apex
B.Roots
C.Mature leaves
D.Flower primordia
- 4.
A brief period of light during the night will promote flowering in:
A.Short-day plants
B.Long-day plants
C.Day-neutral plants
D.None of these
- 5.
Comparing Short-day plants (SDP) and Long-day plants (LDP), which of the following is correct?
A.SDP: Light > Critical; LDP: Light < Critical
B.SDP: Light < Critical; LDP: Light > Critical
C.SDP: Dark < Critical; LDP: Dark > Critical
D.SDP: Dark must be interrupted; LDP: Dark must be continuous
- 6.
Which statement best describes the 'Day-neutral' condition?
A.The plant requires equal periods of light and dark.
B.Flowering is not controlled by the length of the photoperiod.
C.The plant only flowers when the day and night are exactly 12 hours each.
D.The plant requires 24 hours of continuous light to flower.
- 7.
Photoperiodism was discovered when it was noticed that some plants failed to flower in certain seasons because of:
A.Incorrect temperature
B.Insufficient light intensity
C.Inappropriate day length
D.Lack of soil nutrients
- 8.
A researcher applies a chemical that specifically inhibits the protein synthesis in the phloem companion cells of a leaf. What effect will this have on the flowering of an induced plant?
A.No effect, because florigen is a carbohydrate.
B.It will prevent flowering because the FT protein (florigen) cannot be synthesized.
C.It will accelerate flowering as inhibitors are also blocked.
D.The plant will flower, but the flowers will be sterile.
- 9.
If you expose a Long-day plant to 24 hours of continuous light, what is the most likely outcome?
A.It will flower very rapidly because the inductive condition is maximized.
B.It will fail to flower because it needs at least some darkness to 'reset' its clock.
C.It will flower only if the light is purely far-red.
D.It will enter a state of dormancy.
- 10.
Which of the following statements about the role of the form in Short-day plants (SDPs) is correct?
A.It must be present at high levels during the night for flowering.
B.It acts as an inhibitor of flowering; its concentration must drop below a certain threshold during the dark period.
C.It is converted to by red light during the day to trigger flowering.
D.It is the only form of phytochrome found in the seeds of SDPs.
Download the worksheet for Plant Growth and Development - Photoperiodism to practice offline. It includes additional chapter-level practice questions.
Vernalisation
SubtopicVernalisation under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
Vernalisation is a mechanism that allows plants to time their ________ to the appropriate season.
A.Germination
B.Leaf fall
C.Flowering
D.Root branching
- 2.
If we provide a cold treatment to a dry, dormant seed, will vernalisation occur?
A.Yes, always
B.No, seeds must be hydrated
C.Yes, but only in darkness
D.Yes, if the seed coat is thick
- 3.
Which of these crops has both spring and winter varieties?
A.Barley
B.Apple
C.Papaya
D.Sugarcane
- 4.
Vernalisation is specifically a _________ requirement of flowering on low temperature.
A.Quantitative or qualitative
B.Only quantitative
C.Only qualitative
D.Non-essential
- 5.
Why is the 'spring variety' of wheat typically not sown in the autumn in temperate regions, unlike the 'winter variety'?
A.It would fail to germinate because its seeds require high soil temperatures to break dormancy.
B.It is a biennial plant that must complete its vegetative phase only during the summer months.
C.It lacks the physiological delay in flowering provided by a vernalisation requirement, making its early growth vulnerable to winter frost.
D.The seeds of spring varieties are only fertile when the days are progressively getting shorter during the vegetative stage.
- 6.
Vernalisation can be effectively applied to which of the following to induce early flowering in some crops?
A.Dry seeds
B.Germinating seeds
C.Mature fruits
D.Dead wood
- 7.
Which of the following is a biennial plant often used as a source of sugar?
A.Sugarcane
B.Sugarbeet
C.Sweet potato
D.Stevia
- 8.
Which of the following would be an incorrect application of the term 'Vernalisation'?
A.Chilling of winter wheat seeds to allow spring sowing.
B.Cold treatment of carrot rosettes to induce bolting.
C.Storing potato tubers at to prevent sprouting.
D.Exposing cabbage plants to low temperatures to ensure head formation and later flowering.
- 9.
What is the primary ecological advantage of 'devernalisation' occurring if a cold snap is followed by extreme heat?
A.It allows the plant to flower twice in one year.
B.It prevents the plant from 'committing' to flowering if the environment is still too unstable or harsh.
C.It increases the plant's resistance to fungal infections.
D.It ensures that the seeds produced will be larger.
- 10.
Which statement correctly describes the epigenetic inheritance of the vernalised state during vegetative growth?
A.The silenced state of is maintained through mitosis, so new leaves 'remember' the winter.
B.The protein is physically handed off from mother cell to daughter cell.
C.The vernalisation signal is lost every time a cell divides and must be re-perceived.
D.Only the original cells present during the cold treatment remain vernalised.
Download the worksheet for Plant Growth and Development - Vernalisation to practice offline. It includes additional chapter-level practice questions.
Growth (phases, rates and conditions of growth)
SubtopicGrowth (phases, rates and conditions of growth) under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
An increase in the girth of a tree trunk is an example of:
A.Primary growth
B.Secondary growth
C.Apical growth
D.Linear growth
- 2.
In plants, growth is:
A.Confined to certain regions
B.Uniform throughout the plant body
C.Limited to the embryonic stage only
D.Not measurable
- 3.
Which of these is NOT a parameter used to measure growth?
A.Increase in fresh weight
B.Increase in dry weight
C.Increase in cell number
D.Increase in leaf color intensity
- 4.
The exponential growth of a population can be expressed as . Here, '' is also called the:
A.Lag factor
B.Relative growth rate
C.Absolute size
D.Initial weight
- 5.
In the geometric growth equation , the final size of a plant organ is determined by its initial size, the growth rate, and the time period. If two different plants, A and B, have an identical relative growth rate () and are compared over the same time interval (), what will be the result if Plant B starts with a larger initial size () than Plant A?
A.Both plants will reach an identical final size () because their efficiency indices are equal.
B.The initial size () has no mathematical influence on the final size () in exponential growth.
C.Plant B will achieve a higher final size () than Plant A.
D.Plant A will show a higher absolute increase in size because it is more efficient.
- 6.
Which phase of the growth curve represents the period of adaptation to the environment before rapid division?
A.Lag phase
B.Log phase
C.Exponential phase
D.Stationary phase
- 7.
Growth is 'measurable' at the cellular level by an increase in the amount of:
A.Cell wall
B.Protoplasm
C.Vacuolar sap
D.Extracellular fluid
- 8.
In arithmetic growth, why is the graph linear?
A.Because the rate of growth is increasing exponentially.
B.Because a constant number of cells are added per unit time.
C.Because the efficiency index is constant.
D.Because the nutrients are unlimited.
- 9.
What happens during the deceleration phase of growth?
A.Growth stops completely.
B.The rate of growth starts decreasing after the exponential phase.
C.The rate of growth starts increasing slowly.
D.Cells start dividing by meiosis.
- 10.
The growth of which plant part is considered to be 'determinate'?
A.Stem
B.Root
C.Fruit
D.Vascular Cambium
Download the worksheet for Plant Growth and Development - Growth (phases, rates and conditions of growth) to practice offline. It includes additional chapter-level practice questions.
Differentiation, dedifferentiation and redifferentiation
SubtopicDifferentiation, dedifferentiation and redifferentiation under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
Dedifferentiation is possible in plants because:
A.Plant cells are always dividing
B.Plant cells are dead at maturity
C.Mature living plant cells can regain division power
D.Plants do not have specialized tissues
- 2.
Which tissue in a mature dicot stem is a result of redifferentiation?
A.Primary xylem
B.Epidermis
C.Secondary phloem
D.Cortex
- 3.
The loss of protoplasm in tracheary elements allows them to carry out which function?
A.Photosynthesis
B.Water transport
C.Food storage
D.Protection
- 4.
Which of the following is an example of a secondary meristem?
A.Apical meristem
B.Intercalary meristem
C.Cork cambium
D.Protoderm
- 5.
In the context of secondary growth in dicotyledonous plants, analyze the sequence of cellular transitions provided. Which set of examples correctly completes the sequence for 'Stage 1' and 'Stage 3'?
A.Stage 1: Cortical parenchyma; Stage 2: Primary phloem
B.Stage 1: Shoot apical meristem; Stage 3: Secondary xylem
C.Stage 1: Medullary ray cell; Stage 3: Secondary phloem
D.Stage 1: Phellem; Stage 3: Phellogen
- 6.
A student examines the development of two specific plant cells as shown in the diagram. Which of the following statements accurately describes a shared characteristic of 'Root Hair' and 'Phellem' regarding their maturation?
A.Both cells are considered meristematic and retain the ability to divide indefinitely.
B.Both represent a mature functional state where the capacity to divide has been lost.
C.Root hair is a result of dedifferentiation, while phellem is a result of differentiation.
D.Both are primary tissues derived directly from the activity of the shoot apical meristem.
- 7.
The lignocellulosic nature of the secondary cell wall in tracheary elements is established during:
A.Dedifferentiation
B.Redifferentiation
C.Differentiation
D.De-maturation
- 8.
Which of these is NOT a location-specific differentiation product?
A.A cell positioned at the periphery becoming an epidermis
B.A cell pushed to the center becoming a vascular tissue
C.A cell in the root apex becoming a root cap cell
D.A zygote becoming an embryo (this is a general developmental process)
- 9.
Dedifferentiation is a prerequisite for:
A.Primary growth
B.Secondary growth in dicots
C.The formation of the apical meristem
D.Seed germination
- 10.
Which of the following shows the correct relationship between developmental processes?
A.Development = Growth + Differentiation
B.Growth = Development + Differentiation
C.Differentiation = Growth + Development
D.Development = Growth - Differentiation
Download the worksheet for Plant Growth and Development - Differentiation, dedifferentiation and redifferentiation to practice offline. It includes additional chapter-level practice questions.
Development
SubtopicDevelopment under Plant Growth and Development for Grade 11 CBSE.
Preview questions (no answers)
- 1.
Which hormone promotes abscission of older leaves and fruits but inhibits it in younger ones?
A.Ethylene
B.Auxin
C.GA
D.ABA
- 2.
Which of the following plants does NOT show a biennial habit?
A.Sugarbeet
B.Cabbage
C.Carrot
D.Wheat
- 3.
The process by which flowering is either quantitatively or qualitatively dependent on exposure to low temperature is:
A.Photoperiodism
B.Vernalisation
C.Plasticity
D.Differentiation
- 4.
What is the site of perception of light/dark duration in plants?
A.Shoot apex
B.Root apex
C.Leaves
D.Flowers
- 5.
In photoperiodism, the 'Critical Duration' refers to:
A.The maximum light required for flowering
B.The minimum light required for flowering
C.The specific day length that determines flowering
D.The total lifespan of the plant
- 6.
Which of the following processes is responsible for the formation of vascular cambium in the roots of dicots?
A.Differentiation
B.Dedifferentiation
C.Redifferentiation
D.Primary growth
- 7.
Which plant hormone promotes nutrient mobilization and helps in the delay of leaf senescence?
A.Auxin
B.Cytokinin
C.ABA
D.Ethylene
- 8.
The promotion of flowering by a period of low temperature (Vernalization) prevents which of the following?
A.Precocious reproductive development late in the growing season
B.Early vegetative growth in the spring
C.Seed dormancy during the winter
D.Apical dominance during the juvenile phase
- 9.
Which of the following growth regulators is chemically a derivative of carotenoids?
A.Abscisic Acid
B.Gibberellic Acid
C.Indole-3-acetic acid
D.Kinetin
- 10.
In a hypothetical experiment, the removal of the root cap leads to the loss of gravitropic response in the root. This is because the root cap contains specialized cells called:
A.Statocytes containing amyloplasts
B.Aleurone cells containing protein bodies
C.Parenchyma cells containing vacuoles
D.Sclerenchyma cells for protection
Download the worksheet for Plant Growth and Development - Development to practice offline. It includes additional chapter-level practice questions.