ncert - Plant Growth and Development - 24-25
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Questions and Answers

What does W1 represent in the exponential growth formula?

  • Growth rate
  • Time of growth
  • Final size after a period of growth (correct)
  • Initial size at the beginning of the period

    • The relative growth rate is the total growth per unit time.

    False

    What is the base of natural logarithms used in exponential growth formulas?

    e

    The plant cells grow by _____ which requires water.

    <p>cell enlargement</p> Signup and view all the answers

    Which of the following factors is NOT considered essential for plant growth?

    <p>Sunlight</p> Signup and view all the answers

    Match the following terms with their definitions:

    <p>Absolute growth rate = Total growth measurement per unit time Relative growth rate = Growth expressed per unit initial parameter Efficiency index = Ability of plants to produce new material Turgidity = Swollen state of cells due to water intake</p> Signup and view all the answers

    Leaves A and B had the same initial size and increase in area.

    <p>False</p> Signup and view all the answers

    What are the ideal conditions for plant growth mentioned in the text?

    <p>Water, oxygen, and nutrients</p> Signup and view all the answers

    What phase of growth do constantly dividing cells in the root and shoot apex represent?

    <p>Meristematic phase</p> Signup and view all the answers

    What is primarily measured to determine plant growth?

    <p>Increase in protoplasm</p> Signup and view all the answers

    The cells in the maturation phase attain their maximal size through elongation.

    <p>False</p> Signup and view all the answers

    Growth in plants can only be measured by the increase in fresh weight.

    <p>False</p> Signup and view all the answers

    What are the key characteristics of cells in the phase of elongation?

    <p>Increased vacuolation, cell enlargement, and new cell wall deposition.</p> Signup and view all the answers

    The increased growth per unit time is termed as __________.

    <p>growth rate</p> Signup and view all the answers

    How many new cells can a single maize root apical meristem produce per hour?

    <p>17,500</p> Signup and view all the answers

    Match the following types of growth with their characteristics:

    <p>Arithmetic growth = One daughter cell continues to divide Geometric growth = Both daughter cells continue to divide Maturation phase = Maximal size in protoplasmic modifications Elongation phase = Increased vacuolation in cells</p> Signup and view all the answers

    The period of growth in plants is generally divided into three phases: meristematic, elongation, and __________.

    <p>maturation</p> Signup and view all the answers

    Which of the following describes arithmetic growth?

    <p>Only one daughter cell continues to divide.</p> Signup and view all the answers

    Match the following growth parameters to their description:

    <p>Fresh weight = Total weight of the plant, including water content Dry weight = Weight of the plant without water Cell number = Total number of cells in a plant Cell size = Measurement of the individual cell dimensions</p> Signup and view all the answers

    Which plant's cells can increase in size by up to 350,000 times?

    <p>Watermelon</p> Signup and view all the answers

    The primary cell walls in the meristematic phase are thick and lignified.

    <p>False</p> Signup and view all the answers

    What mathematical expression can describe the rate of growth?

    <p>Growth rate can be expressed through formulas that analyze the increase of cells over time.</p> Signup and view all the answers

    The growth of a pollen tube is primarily measured by its weight.

    <p>False</p> Signup and view all the answers

    What are the three phases of plant growth?

    <p>Meristematic, elongation, maturation</p> Signup and view all the answers

    What determines the final structure of a cell/tissue at maturity?

    <p>The location of the cell within the plant</p> Signup and view all the answers

    Development in plants is solely influenced by intrinsic factors.

    <p>False</p> Signup and view all the answers

    What is heterophylly?

    <p>The phenomenon where a plant exhibits different leaf shapes at various stages of its life cycle or due to environmental conditions.</p> Signup and view all the answers

    The process by which a meristematic cell matures and takes on its final form is called __________.

    <p>differentiation</p> Signup and view all the answers

    Which of the following is an example of environmental influence on plant structure?

    <p>Different leaf shapes in water vs. air in buttercup</p> Signup and view all the answers

    What is the significance of the root apical meristem in plant cells?

    <p>It is responsible for the growth of the root and influences the differentiation of cells located near it.</p> Signup and view all the answers

    The sequence of processes in plant cell development includes cell death as a final stage.

    <p>True</p> Signup and view all the answers

    Which plant growth regulator is known as the stress hormone?

    <p>Abscisic acid</p> Signup and view all the answers

    Diverse plant growth regulators can have both synergistic and antagonistic effects on growth.

    <p>True</p> Signup and view all the answers

    What is meant by 'determinate growth' in plants?

    <p>Determinate growth refers to the type of growth that stops once a certain structure or size is achieved.</p> Signup and view all the answers

    The type of growth where the rate of growth accelerates continuously is called __________ growth.

    <p>geometric</p> Signup and view all the answers

    Match the following plant growth regulators with their primary effects:

    <p>Auxin = Induces rooting in cuttings Cytokinin = Promotes cell division Gibberellin = Stimulates stem elongation Ethylene = Accelerates fruit ripening</p> Signup and view all the answers

    Which of the following is NOT a type of plant growth regulator?

    <p>Chloroplasts</p> Signup and view all the answers

    Plant growth regulators can only promote growth activities in plants.

    <p>False</p> Signup and view all the answers

    What is the role of abscisic acid in plants?

    <p>It plays a role in plant responses to stresses and inhibits growth activities.</p> Signup and view all the answers

    The gaseous plant growth regulator ________ is largely an inhibitor of growth activities.

    <p>ethylene</p> Signup and view all the answers

    Match the following plant growth regulators with their primary functions:

    <p>Auxins = Growth promotion activities Gibberellins = Cell enlargement and flowering Cytokinins = Cell division Abscisic Acid = Inhibition and dormancy</p> Signup and view all the answers

    Which group of plant growth regulators is involved in growth promotion?

    <p>Auxins, gibberellins, and cytokinins</p> Signup and view all the answers

    The discovery of the major groups of plant growth regulators was intentional and planned.

    <p>False</p> Signup and view all the answers

    Name one characteristic of plant growth regulators.

    <p>They are small, simple molecules of diverse chemical composition.</p> Signup and view all the answers

    What does the variable 'r' in the exponential growth formula represent?

    <p>Growth rate</p> Signup and view all the answers

    The absolute growth rate is the growth measured per unit time on a common basis.

    <p>False</p> Signup and view all the answers

    What are two factors essential for plant growth?

    <p>Water and nutrients</p> Signup and view all the answers

    Plant cells enlarge through ________, which requires water.

    <p>cell enlargement</p> Signup and view all the answers

    Which statement is true regarding the relative growth rate?

    <p>It is expressed per unit initial size.</p> Signup and view all the answers

    Match the following growth rates with their definitions:

    <p>Absolute growth rate = Total growth over time Relative growth rate = Growth per unit initial size</p> Signup and view all the answers

    In the context of plant growth, what effect does turgidity have?

    <p>It helps in cell extension growth.</p> Signup and view all the answers

    What shape does the growth curve typically take during the exponential phase of growth?

    <p>Sigmoid</p> Signup and view all the answers

    What is the significance of measuring absolute growth rates in plant studies?

    <p>It allows for evaluation of total growth under specific conditions.</p> Signup and view all the answers

    Cells in the lag phase of growth experience rapid growth.

    <p>False</p> Signup and view all the answers

    What is the expression for arithmetic growth?

    <p>Lt = L0 + rt</p> Signup and view all the answers

    Initially, cell growth begins slowly in the ______ phase.

    <p>lag</p> Signup and view all the answers

    Match the following phases of growth with their descriptions:

    <p>Lag phase = Slow initial growth Exponential phase = Rapid growth Stationary phase = Growth slows due to limited resources Maturation phase = Cells attain maximal size</p> Signup and view all the answers

    What happens during the stationary phase of growth?

    <p>Growth rate slows down due to limited nutrients</p> Signup and view all the answers

    The growth curve is always linear for all living organisms.

    <p>False</p> Signup and view all the answers

    The acronym 'L0' represents the length at time ______.

    <p>zero</p> Signup and view all the answers

    What is the process called when a differentiated cell regains the ability to divide?

    <p>Dedifferentiation</p> Signup and view all the answers

    Oxygen is not essential for metabolic activities required for plant growth.

    <p>False</p> Signup and view all the answers

    Name one environmental signal that can affect plant growth.

    <p>Light</p> Signup and view all the answers

    Water provides the medium for __________ activities needed for plant growth.

    <p>enzymatic</p> Signup and view all the answers

    Which factor is NOT essential for plant growth?

    <p>Magnetic fields</p> Signup and view all the answers

    Plants can only grow within a specific temperature range.

    <p>True</p> Signup and view all the answers

    What is a characteristic change that takes place during differentiation?

    <p>Structural changes in cell walls and protoplasm</p> Signup and view all the answers

    What is the first step in the process of plant growth?

    <p>Seed Germination</p> Signup and view all the answers

    All cells of a plant are derived from the zygote.

    <p>True</p> Signup and view all the answers

    What term describes the period when seeds do not germinate due to unfavorable conditions?

    <p>Suspended growth</p> Signup and view all the answers

    Development in plants encompasses growth and __________.

    <p>differentiation</p> Signup and view all the answers

    Which factors influence plant development?

    <p>Both intrinsic and extrinsic factors</p> Signup and view all the answers

    Leaves, flowers, and fruits of a tree grow indefinitely throughout its life.

    <p>False</p> Signup and view all the answers

    What are the two processes that comprise development in plants?

    <p>Growth and differentiation</p> Signup and view all the answers

    What is the term used to describe the ability of plants to form different structures in response to environmental changes?

    <p>Plasticity</p> Signup and view all the answers

    The sequence of processes in plant cell development includes only growth and maturation.

    <p>False</p> Signup and view all the answers

    What happens to cells positioned away from the root apical meristem?

    <p>They differentiate as root-cap cells.</p> Signup and view all the answers

    Heterophylly is the phenomenon where juvenile leaves differ in shape from those in the __________ stage.

    <p>mature</p> Signup and view all the answers

    Which of the following represents an example of heterophylly due to environmental factors?

    <p>Buttercup leaves produced in air vs. water</p> Signup and view all the answers

    Match the following stages of plant development with their descriptions:

    <p>Meristematic = Cells actively dividing Differentiation = Specialization of cells Expansion = Increase in cell size Senescence = Aging and dying of the cell</p> Signup and view all the answers

    Development in plants is influenced solely by intrinsic factors.

    <p>False</p> Signup and view all the answers

    What is the final stage of the developmental process in a plant cell?

    <p>Senescence</p> Signup and view all the answers

    Which of the following is NOT classified as a plant growth regulator?

    <p>Chlorophyll</p> Signup and view all the answers

    Growth promoters in plant growth regulators include auxins, gibberellins, and abscisic acid.

    <p>False</p> Signup and view all the answers

    What group of plant growth regulators helps plants respond to wounds and stresses?

    <p>Growth inhibitors</p> Signup and view all the answers

    The gaseous plant growth regulator __________ can act as both a promoter and inhibitor of growth activities.

    <p>ethylene</p> Signup and view all the answers

    Match the following plant growth regulators with their characteristics:

    <p>Auxins = Involved in cell enlargement Gibberellins = Promote stem elongation Abscisic Acid = Induces dormancy Ethylene = Stimulates fruit ripening</p> Signup and view all the answers

    Which of the following PGRs is primarily involved in plant growth promotion?

    <p>Cytokinins</p> Signup and view all the answers

    All major groups of plant growth regulators were discovered intentionally.

    <p>False</p> Signup and view all the answers

    Identify one characteristic of plant growth regulators.

    <p>They are small, simple molecules.</p> Signup and view all the answers

    Which of the following best describes the process of development in plants?

    <p>Involves both growth and differentiation.</p> Signup and view all the answers

    All plant cells share the same structure regardless of their function.

    <p>False</p> Signup and view all the answers

    Development in plants is influenced by both _____ and external factors.

    <p>intrinsic</p> Signup and view all the answers

    Match the following phases of plant growth with their descriptions:

    <p>Meristematic = Cells actively divide. Elongation = Cells increase in size. Maturation = Cells attain their final form.</p> Signup and view all the answers

    Which statement accurately reflects the behavior of seeds under unfavorable conditions?

    <p>They remain dormant.</p> Signup and view all the answers

    Vegetative growth occurs after flowering in a plant.

    <p>False</p> Signup and view all the answers

    Name one type of internal factor that influences plant growth and development.

    <p>Plant hormones</p> Signup and view all the answers

    Which group of plant growth regulators is primarily involved in promoting growth activities?

    <p>Auxins</p> Signup and view all the answers

    Ethylene is only classified as a growth promoter among plant growth regulators.

    <p>False</p> Signup and view all the answers

    Plant growth regulators that involve responses to wounds and stresses are termed __________.

    <p>growth inhibitors</p> Signup and view all the answers

    Match each type of plant growth regulator to its primary role:

    <p>Auxins = Promoting cell elongation Gibberellins = Stimulating flowering Abscisic acid = Inducing dormancy Ethylene = Regulating fruit ripening</p> Signup and view all the answers

    What are plant growth regulators also known as?

    <p>Plant hormones</p> Signup and view all the answers

    The discovery of plant growth regulators was intentional and systematically done.

    <p>False</p> Signup and view all the answers

    Which plant growth regulator is considered the stress hormone?

    <p>Abscisic acid</p> Signup and view all the answers

    Which of the following are synthetic auxins?

    <p>2, 4-D (2, 4-dichlorophenoxyacetic)</p> Signup and view all the answers

    Auxins inhibit the growth of lateral (axillary) buds through a phenomenon known as apical dominance.

    <p>True</p> Signup and view all the answers

    What is the primary effect of gibberellins in plants?

    <p>Promotion of growth</p> Signup and view all the answers

    Auxins help to initiate rooting in stem cuttings, which is widely used for __________.

    <p>plant propagation</p> Signup and view all the answers

    Match the following plant growth regulators with their functions:

    <p>Auxins = Promote flowering and rooting Gibberellins = Stimulate stem elongation NAA = Synthetic auxin used in agriculture 2, 4-D = Herbicide for dicotyledonous weeds</p> Signup and view all the answers

    Which plant growth regulator is primarily known for preventing fruit and leaf drop?

    <p>Auxins</p> Signup and view all the answers

    2, 4-D impacts mature monocotyledonous plants.

    <p>False</p> Signup and view all the answers

    The substance known as auxin is derived from __________ acid.

    <p>indole-3-acetic</p> Signup and view all the answers

    Which of the following actions is NOT influenced by ethylene in plants?

    <p>Enhancing photosynthesis</p> Signup and view all the answers

    Abscisic acid is primarily associated with promoting seed germination.

    <p>False</p> Signup and view all the answers

    What effect does ethylene have on fruit ripening?

    <p>Ethylene enhances the respiration rate during ripening, promoting faster ripening.</p> Signup and view all the answers

    Ethylene promotes _____ of plant organs, particularly leaves and flowers.

    <p>abscission</p> Signup and view all the answers

    Which of the following PGRs is known as the stress hormone?

    <p>Abscisic acid</p> Signup and view all the answers

    Match the following effects with the corresponding plant growth regulator:

    <p>Ethylene = Rapid fruit ripening Abscisic acid = Inhibits germination Gibberellins = Promotes stem elongation Cytokinins = Stimulates cell division</p> Signup and view all the answers

    What is the role of ethylene in deep water rice plants?

    <p>Ethylene promotes rapid internode/petiole elongation, allowing upper parts to remain above water.</p> Signup and view all the answers

    Ethephon is used as a source of gibberellins to promote vegetative growth in plants.

    <p>False</p> Signup and view all the answers

    Which group of plant growth regulators primarily promotes cell division and differentiation?

    <p>Cytokinins</p> Signup and view all the answers

    The growth of plants is entirely governed by intrinsic factors such as plant growth regulators.

    <p>False</p> Signup and view all the answers

    What are the three principal phases of growth in plants?

    <p>lag, log, and senescent phase</p> Signup and view all the answers

    The chemical substances that regulate plant growth are known as __________.

    <p>plant growth regulators</p> Signup and view all the answers

    Which of the following events is influenced by temperature as an extrinsic factor?

    <p>Flowering</p> Signup and view all the answers

    Plant differentiation is a process that cannot reverse once it has occurred.

    <p>False</p> Signup and view all the answers

    What is the role of apical meristems in plant growth?

    <p>Sites of growth for root and shoot elongation</p> Signup and view all the answers

    Which of the following statements is true regarding the role of light in plant growth?

    <p>Light affects both growth and differentiation in plants.</p> Signup and view all the answers

    Define dedifferentiation in plants.

    <p>Dedifferentiation is the process by which mature cells revert to a less specialized state.</p> Signup and view all the answers

    Abscisic acid is often referred to as the __________ hormone.

    <p>stress</p> Signup and view all the answers

    Match the following plant growth regulators with their primary applications:

    <p>Auxins = Inducing rooting Gibberellins = Promoting fruit ripening Cytokinins = Delaying leaf senescence Ethylene = Accelerating flower and fruiting processes</p> Signup and view all the answers

    Which growth measurement primarily indicates the increase in size of a cell?

    <p>Increase in surface area</p> Signup and view all the answers

    The growth phases of plants include meristematic, elongation, and maturation.

    <p>True</p> Signup and view all the answers

    What is the primary consequence of vascular cambium growth in plants?

    <p>Increase in the amount of protoplasm</p> Signup and view all the answers

    A single maize root apical meristem can produce more than _______ new cells per hour.

    <p>17,500</p> Signup and view all the answers

    Which of the following parameters is NOT used to measure plant growth?

    <p>Increase in temperature</p> Signup and view all the answers

    Cells in the elongation phase primarily contribute to an increase in cell number.

    <p>False</p> Signup and view all the answers

    What is the mathematical expression for arithmetic growth?

    <p>Lt = L0 + rt</p> Signup and view all the answers

    A sigmoid curve is typical for all cells, tissues, and organs of a plant.

    <p>True</p> Signup and view all the answers

    What phase of growth is characterized by initially slow growth followed by rapid exponential growth?

    <p>exponential phase</p> Signup and view all the answers

    The phase where growth begins to slow down due to limited nutrient supply is known as the __________ phase.

    <p>stationary</p> Signup and view all the answers

    Match the following growth phases with their descriptions:

    <p>Lag phase = Initial slow growth Exponential phase = Rapid growth Stationary phase = Growth slows due to nutrient limitation Death phase = Decline in growth or size</p> Signup and view all the answers

    In a typical growth curve of a living organism, what shape is formed?

    <p>Sigmoid curve</p> Signup and view all the answers

    The growth rate 'r' in the equation Lt = L0 + rt represents the nutrient supply.

    <p>False</p> Signup and view all the answers

    What kind of growth is depicted by a linear relationship between length and time?

    <p>arithmetic growth</p> Signup and view all the answers

    What substance was identified as being responsible for the growth response towards light in canary grass coleoptiles?

    <p>Auxin</p> Signup and view all the answers

    What is the term used for the phenomenon where the growing apical bud inhibits the growth of lateral buds?

    <p>Apical dominance</p> Signup and view all the answers

    Ethylene is primarily known as a growth inhibitor in plants.

    <p>False</p> Signup and view all the answers

    Auxins like 2,4-D can promote flowering in higher plants.

    <p>False</p> Signup and view all the answers

    Name the plant growth regulator that was confirmed to be released from ripened oranges and hastens the ripening process.

    <p>Ethylene</p> Signup and view all the answers

    What synthetic auxin is commonly used to kill dicotyledonous weeds?

    <p>2,4-D</p> Signup and view all the answers

    The fungal pathogen responsible for 'bakanae' disease in rice is ________.

    <p>Gibberella fujikuroi</p> Signup and view all the answers

    Gibberellins are known to promote __________ in plants.

    <p>growth</p> Signup and view all the answers

    Match the following auxins with their characteristics:

    <p>IAA = Natural auxin involved in growth regulation IBA = Used to initiate rooting in cuttings NAA = Synthetic auxin used in agriculture 2,4-D = Synthetic auxin used as a herbicide</p> Signup and view all the answers

    What was the active substance identified from the internodal segments of tobacco stems that promotes cell proliferation?

    <p>Kinetin</p> Signup and view all the answers

    Which auxin is known for inducing parthenocarpy?

    <p>Indole-3-acetic acid</p> Signup and view all the answers

    What are the three independent inhibitors characterized in the mid-1960s that were later identified as abscisic acid?

    <p>Inhibitor-B, abscission II, and dormin</p> Signup and view all the answers

    Removing the shoot tips of a plant will always inhibit the growth of lateral buds.

    <p>False</p> Signup and view all the answers

    F.W. Went isolated auxin from the tips of the coleoptiles in canary grass.

    <p>True</p> Signup and view all the answers

    Name one application of auxins in agricultural practices.

    <p>Initiating rooting in stem cuttings</p> Signup and view all the answers

    Which plant growth regulator is known for promoting the ripening of fruits?

    <p>Ethylene</p> Signup and view all the answers

    Abscisic acid promotes seed germination.

    <p>False</p> Signup and view all the answers

    What role does ethylene play in deep water rice plants?

    <p>It promotes rapid internode and petiole elongation.</p> Signup and view all the answers

    Ethephon is a compound used as a source of ________.

    <p>ethylene</p> Signup and view all the answers

    Which of the following effects is NOT associated with ethylene?

    <p>Facilitating bud dormancy</p> Signup and view all the answers

    What is the term for the rise in respiration rate during fruit ripening due to ethylene?

    <p>Respiratory climactic</p> Signup and view all the answers

    Abscisic acid is also referred to as the ________ hormone.

    <p>stress</p> Signup and view all the answers

    Which of the following is NOT a phase of plant growth?

    <p>Reversal phase</p> Signup and view all the answers

    Growth in plants is determined solely by intrinsic factors.

    <p>False</p> Signup and view all the answers

    Name one plant growth regulator involved in cell differentiation.

    <p>Auxins</p> Signup and view all the answers

    The process by which a plant goes through various growth and development phases is called ________.

    <p>differentiation</p> Signup and view all the answers

    Which of the following events is influenced by both PGRs and environmental factors?

    <p>Vernalisation</p> Signup and view all the answers

    The apical dominance in plants is regulated entirely by external environmental factors.

    <p>False</p> Signup and view all the answers

    What type of growth is characterized by an irregular increase in the number of plant cells?

    <p>Indeterminate growth</p> Signup and view all the answers

    All seeds will germinate regardless of environmental conditions.

    <p>False</p> Signup and view all the answers

    What two processes make up development in plants?

    <p>Growth and differentiation</p> Signup and view all the answers

    Once favorable conditions return, seeds resume __________ activities.

    <p>metabolic</p> Signup and view all the answers

    Match the following phases of growth to their definitions:

    <p>Meristematic = Constantly dividing cells Elongation = Cells increase in size Maturation = Cells attain their final form Dormancy = Suspended growth period</p> Signup and view all the answers

    Which of the following defines the relationship between structure and function in plant organs?

    <p>The structure of a cell affects its function.</p> Signup and view all the answers

    The leaves, flowers, and fruits of a tree grow indefinitely.

    <p>False</p> Signup and view all the answers

    What types of factors influence plant development?

    <p>Intrinsic and extrinsic</p> Signup and view all the answers

    What is responsible for the phase of elongation in plant growth?

    <p>Cell vacuolation</p> Signup and view all the answers

    The meristematic phase involves cells that differentiate and mature.

    <p>False</p> Signup and view all the answers

    What mathematical term is used to describe the increased growth per unit time?

    <p>growth rate</p> Signup and view all the answers

    Cells in the maturation phase undergo maximal wall thickening and protoplasmic modifications, reaching their maximum size in the __________ of growth.

    <p>maturation</p> Signup and view all the answers

    Which of the following is NOT a characteristic of the cells in the meristematic phase?

    <p>Thick cell walls</p> Signup and view all the answers

    Arithmetic growth means that both daughter cells from mitosis continue to divide.

    <p>False</p> Signup and view all the answers

    What happens to one of the daughter cells in arithmetic growth?

    <p>It differentiates and matures.</p> Signup and view all the answers

    What type of curve characterizes geometrical growth in living organisms?

    <p>Sigmoid curve</p> Signup and view all the answers

    In the stationary phase, growth continues at the same rapid rate as during the exponential phase.

    <p>False</p> Signup and view all the answers

    Define the term 'lag phase' in relation to growth.

    <p>The initial slow growth period before rapid increase.</p> Signup and view all the answers

    The formula for arithmetic growth can be expressed as ________.

    <p>Lt = L0 + rt</p> Signup and view all the answers

    Match the types of growth with their descriptions:

    <p>Arithmetic growth = Constant rate elongation over time Geometric growth = Initial slow growth followed by rapid increase Stationary phase = Growth slows due to limited resources Exponential growth = Rapid growth rate leading to a steep curve</p> Signup and view all the answers

    What does 'r' represent in the equations describing growth?

    <p>Growth rate per unit time</p> Signup and view all the answers

    The growth pattern of plants can be described as following a typical S-curve due to environmental factors.

    <p>True</p> Signup and view all the answers

    What happens to growth during the stationary phase?

    <p>Growth slows down and stabilizes.</p> Signup and view all the answers

    What is the main characteristic of plant growth?

    <p>Plants can grow indefinitely due to meristem activity.</p> Signup and view all the answers

    Plant growth can be defined as a reversible increase in size.

    <p>False</p> Signup and view all the answers

    Name the two types of meristems responsible for primary growth in plants.

    <p>Root apical meristem and shoot apical meristem.</p> Signup and view all the answers

    The form of growth in which new cells are continuously added to the plant body is called __________ growth.

    <p>open</p> Signup and view all the answers

    What happens if the meristem ceases to divide?

    <p>Growth will slow down significantly but not stop.</p> Signup and view all the answers

    The vascular cambium is involved in increasing the girth of plant organs.

    <p>True</p> Signup and view all the answers

    Describe the relationship between plant growth and metabolic processes.

    <p>Plant growth is accompanied by metabolic processes, both anabolic and catabolic, that require energy.</p> Signup and view all the answers

    What is the term that describes the ability of plants to form different kinds of structures in response to their environment?

    <p>Plasticity</p> Signup and view all the answers

    The final structure at maturity of a cell or tissue is solely determined by genetic factors.

    <p>False</p> Signup and view all the answers

    What is the process called that involves the maturation of a meristematic cell into its final form?

    <p>Differentiation</p> Signup and view all the answers

    Heterophylly in plants is an example of __________.

    <p>plasticity</p> Signup and view all the answers

    Match the following concepts with their definitions:

    <p>Meristematic Cells = Cells that have the potential to divide and differentiate Senescence = The process of aging and decline Expanded Cells = Cells that have reached their maximal size through elongation Differentiation = The process through which cells develop distinct functions</p> Signup and view all the answers

    Which of the following statements accurately describes the developmental process in plants?

    <p>Development comprises growth, differentiation, and senescence.</p> Signup and view all the answers

    Cells positioned away from the root apical meristem differentiate as root-cap cells.

    <p>True</p> Signup and view all the answers

    What phenomenon describes the difference in leaf shapes in juvenile and mature plants, as seen in cotton, coriander, and larkspur?

    <p>Heterophylly</p> Signup and view all the answers

    Which of the following plant growth regulators is primarily involved in growth inhibition?

    <p>Abscisic acid</p> Signup and view all the answers

    Plant growth promoters, such as auxins and gibberellins, have no role in cell division.

    <p>False</p> Signup and view all the answers

    What are the two broad groups of plant growth regulators based on their functions?

    <p>Growth promoting and growth inhibiting</p> Signup and view all the answers

    Gaseous plant growth regulator ________ is primarily known as a growth inhibitor.

    <p>ethylene</p> Signup and view all the answers

    Match the following plant growth regulators with their types:

    <p>Auxins = Plant growth promoters Gibberellins = Plant growth promoters Abscisic acid = Growth inhibitors Ethylene = Growth inhibitors/Promoters</p> Signup and view all the answers

    Which of the following statements is true regarding the discovery of plant growth regulators?

    <p>Each major group was discovered accidentally.</p> Signup and view all the answers

    Plant growth regulators are synthetically produced only.

    <p>False</p> Signup and view all the answers

    What is the primary method for measuring growth at a cellular level?

    <p>Increase in fresh weight</p> Signup and view all the answers

    The growth of a pollen tube is measured by its surface area.

    <p>False</p> Signup and view all the answers

    Name the three phases of growth in plants.

    <p>meristematic, elongation, maturation</p> Signup and view all the answers

    Match the following parameters of growth with their descriptions:

    <p>Fresh weight = Weight of the plant including water content Dry weight = Weight of the plant after removing moisture Cell number = Count of individual cells in a given volume Length = Measurement of the longest part of the plant</p> Signup and view all the answers

    Which of the following best describes the elongation phase of growth?

    <p>Cells increasing in size</p> Signup and view all the answers

    Cell growth in plants can be characterized only by increase in cell number.

    <p>False</p> Signup and view all the answers

    Growth in a dorsiventral leaf is measured by an increase in its ______.

    <p>surface area</p> Signup and view all the answers

    What role does water play in plant growth?

    <p>It provides a medium for enzymatic activities.</p> Signup and view all the answers

    Plants can undergo dedifferentiation and regain the capacity to divide.

    <p>True</p> Signup and view all the answers

    What is the process called when cells mature and assume specific functions?

    <p>Differentiation</p> Signup and view all the answers

    The internal conditions under which plants best grow are referred to as their ________ temperature range.

    <p>optimum</p> Signup and view all the answers

    Match the following plant processes with their definitions:

    <p>Differentiation = Maturation of cells to perform specific functions Dedifferentiation = Regaining the capacity to divide Redifferentiation = Maturing again after division Meristem = Tissue with cells capable of division</p> Signup and view all the answers

    What happens to cells when they differentiate to form tracheary elements?

    <p>They lose their protoplasm and have strong cell walls.</p> Signup and view all the answers

    Environmental signals such as light have no effect on plant growth.

    <p>False</p> Signup and view all the answers

    In plant tissue culture, what are the parenchyma cells that are made to divide called?

    <p>Callus cells</p> Signup and view all the answers

    What substance was identified as the active component causing symptoms of 'bakanae' disease in rice seedlings?

    <p>Gibberellic acid</p> Signup and view all the answers

    Ethylene is a gaseous plant growth regulator that inhibits plant growth activities.

    <p>False</p> Signup and view all the answers

    Who isolated auxin from the tips of coleoptiles?

    <p>F.W. Went</p> Signup and view all the answers

    The chemical that was later identified as abscisic acid was first reported as _______ and was found to be chemically identical.

    <p>inhibitor-B</p> Signup and view all the answers

    What is the primary function of cytokinins in plants?

    <p>Stimulating cell division</p> Signup and view all the answers

    The callus formed from tobacco stem segments proliferated with auxins alone.

    <p>False</p> Signup and view all the answers

    What did H.H. Cousins observe being released from ripened oranges?

    <p>a volatile substance that hastened banana ripening</p> Signup and view all the answers

    What type of growth occurs when the rate of growth accelerates continuously?

    <p>Geometric growth</p> Signup and view all the answers

    What is the primary role of auxins in plants?

    <p>Initiate rooting in stem cuttings</p> Signup and view all the answers

    The use of natural plant growth regulators is limited only to promoting plant growth.

    <p>False</p> Signup and view all the answers

    Synthetic auxins do not affect any type of plants.

    <p>False</p> Signup and view all the answers

    Define 'dedifferentiation' in plant physiology.

    <p>Dedifferentiation is the process by which specialized cells revert to a less specialized state, often allowing for new growth forms or structures.</p> Signup and view all the answers

    What phenomenon describes the growth inhibition of lateral buds by the apical bud?

    <p>Apical dominance</p> Signup and view all the answers

    Abscisic acid is often referred to as the __________ hormone due to its role in stress responses in plants.

    <p>stress</p> Signup and view all the answers

    Auxins are widely used as _____ in agriculture.

    <p>herbicides</p> Signup and view all the answers

    Which plant growth regulator is primarily associated with promoting flowering?

    <p>Auxins</p> Signup and view all the answers

    Gibberellins are produced primarily in the roots of plants.

    <p>False</p> Signup and view all the answers

    Explain the effect of removing shoot tips (decapitation) in plants.

    <p>It stimulates the growth of lateral buds.</p> Signup and view all the answers

    Which plant growth regulator is primarily responsible for promoting cell elongation?

    <p>Gibberellins</p> Signup and view all the answers

    Plasticity in development refers to the rigidity of plant structure and function.

    <p>False</p> Signup and view all the answers

    Plant movements can be influenced by __________ factors such as light and temperature.

    <p>extrinsic</p> Signup and view all the answers

    Which of the following events is regulated by both intrinsic and extrinsic factors?

    <p>Vernalisation</p> Signup and view all the answers

    Abscisic acid is known as a growth-promoting hormone in plants.

    <p>False</p> Signup and view all the answers

    What role do meristems play in plant growth?

    <p>They are the sites of growth.</p> Signup and view all the answers

    What are the two main processes that contribute to plant development?

    <p>Growth and differentiation</p> Signup and view all the answers

    The cellular structure and function of all plant cells are identical.

    <p>False</p> Signup and view all the answers

    What triggers the germination of a seed?

    <p>Favorable environmental conditions</p> Signup and view all the answers

    The first step in the process of plant growth is _____ germination.

    <p>seed</p> Signup and view all the answers

    Match the following plant tissues with their functions:

    <p>Meristematic tissue = Continuous growth and cell division Parenchyma = Storage and metabolic functions Collenchyma = Support in young stems Sclerenchyma = Support in mature tissues</p> Signup and view all the answers

    Which of the following statements about the development of plants is true?

    <p>Plants have a precise and ordered succession of events during their development.</p> Signup and view all the answers

    Plant growth can only be influenced by external factors.

    <p>False</p> Signup and view all the answers

    What is the significance of the root apical meristem?

    <p>It is responsible for the growth of roots.</p> Signup and view all the answers

    Which of the following is considered a plant growth promoter?

    <p>Gibberellic acid</p> Signup and view all the answers

    Ethylene is primarily a growth promoter in plants.

    <p>False</p> Signup and view all the answers

    Name one group of plant growth regulators that inhibits growth.

    <p>Abscisic acid</p> Signup and view all the answers

    Plant growth regulators classified as _______ are involved in activities such as flowering and seed formation.

    <p>promoters</p> Signup and view all the answers

    What characteristic is common among plant growth regulators?

    <p>They can vary greatly in chemical composition.</p> Signup and view all the answers

    Match the following plant growth regulators with their respective types:

    <p>Auxins = Promoters Abscisic acid = Inhibitors Gibberellins = Promoters Ethylene = Inhibitors</p> Signup and view all the answers

    The discovery of plant growth regulators was intentional and planned.

    <p>False</p> Signup and view all the answers

    What is one effect of ethylene on plants?

    <p>Promotes abscission</p> Signup and view all the answers

    Abscisic acid (ABA) stimulates seed germination.

    <p>False</p> Signup and view all the answers

    What is the primary gaseous plant growth regulator responsible for fruit ripening?

    <p>Ethylene</p> Signup and view all the answers

    Ethephon releases ________ slowly within the plant.

    <p>ethylene</p> Signup and view all the answers

    Match the following effects with the respective plant growth regulators:

    <p>Ethylene = Promotes fruit ripening Abscisic Acid = Inhibits germination Ethephon = Releases ethylene Gibberellins = Promotes stem elongation</p> Signup and view all the answers

    Which process does ethylene enhance during fruit ripening?

    <p>Respiration</p> Signup and view all the answers

    Abscisic acid is referred to as the stress hormone in plants.

    <p>True</p> Signup and view all the answers

    Ethylene promotes ________ growth and root hair formation.

    <p>root</p> Signup and view all the answers

    What substance was identified by F.W. Went as causing the bending of the coleoptile due to phototropism?

    <p>Auxin</p> Signup and view all the answers

    Gibberella fujikuroi is responsible for causing 'bakanae' disease in rice seedlings.

    <p>True</p> Signup and view all the answers

    What is the gaseous plant growth regulator that accelerates the ripening of fruits?

    <p>Ethylene</p> Signup and view all the answers

    The active substance causing the growth abnormalities in 'bakanae' disease was identified as __________.

    <p>gibberellic acid</p> Signup and view all the answers

    Which of the following substances was later identified as having the same chemical identity as three different inhibitors?

    <p>Abscisic Acid</p> Signup and view all the answers

    The internodal segments of tobacco stems can proliferate without the addition of auxins.

    <p>False</p> Signup and view all the answers

    Name one experiment that demonstrated the site of transmittable influence in coleoptiles.

    <p>Darwin's experiment on phototropism</p> Signup and view all the answers

    Which of the following is a primary effect of gibberellins (GA3) when applied to rice seedlings?

    <p>Enhanced elongation of stems</p> Signup and view all the answers

    Dedifferentiation occurs when specialized cells revert to a less specialized state.

    <p>True</p> Signup and view all the answers

    What term describes the phenomenon of plants having potential for growth and differentiation throughout their life?

    <p>Open growth</p> Signup and view all the answers

    The term for the type of growth where the size of a population grows at a constant rate is __________ growth.

    <p>geometric</p> Signup and view all the answers

    Match the following plant growth regulators with their associated functions:

    <p>Auxins = Induce rooting and cell elongation Cytokinins = Delay leaf senescence Ethylene = Promote fruit ripening Abscisic Acid = Induce stomatal closure</p> Signup and view all the answers

    Which of the following plant growth regulators (PGRs) is primarily known for promoting cell division?

    <p>Cytokinins</p> Signup and view all the answers

    Plant growth is solely influenced by intrinsic factors.

    <p>False</p> Signup and view all the answers

    Which of the following events does NOT involve the influence of light and temperature as extrinsic factors?

    <p>Apical Dominance</p> Signup and view all the answers

    Meristematic growth is characterized by irreversible increases in plant size.

    <p>False</p> Signup and view all the answers

    Plant growth and development occur under the control of ________ and ________ factors.

    <p>intrinsic, extrinsic</p> Signup and view all the answers

    What is the phase of growth characterized by increased vacuolation and cell enlargement?

    <p>Phase of elongation</p> Signup and view all the answers

    Arithmetic growth involves both daughter cells continuing to divide after mitotic cell division.

    <p>False</p> Signup and view all the answers

    What type of growth shows an increase that may be geometric or arithmetic?

    <p>Growth rate</p> Signup and view all the answers

    The cells in the region of the root that undergo active division are referred to as __________ cells.

    <p>meristematic</p> Signup and view all the answers

    Match the following growth types with their characteristics:

    <p>Arithmetic growth = One daughter cell continues to divide, the other matures Geometric growth = Both daughter cells continue to divide Maturation phase = Cells reach maximal size and differentiation occurs Meristematic phase = Rapid division of undifferentiated cells</p> Signup and view all the answers

    Which part of the plant primarily experiences growth in the meristematic phase?

    <p>Root tip</p> Signup and view all the answers

    Cell walls in the meristematic phase are typically thick and lignified.

    <p>False</p> Signup and view all the answers

    The growth rate can be expressed __________.

    <p>mathematically</p> Signup and view all the answers

    Which of the following factors does NOT influence plant growth and development?

    <p>Cloudiness</p> Signup and view all the answers

    Plant growth regulators can only act synergistically.

    <p>False</p> Signup and view all the answers

    What is the term for the growth that occurs in a constant ratio over time?

    <p>Geometric growth</p> Signup and view all the answers

    _____ is known as the stress hormone in plants.

    <p>Abscisic acid</p> Signup and view all the answers

    What defines the ability of plants to form different kinds of structures in response to the environment or phases of life?

    <p>Plasticity</p> Signup and view all the answers

    The final structure of a cell at maturity is only determined by its genetic makeup.

    <p>False</p> Signup and view all the answers

    What is the term for the changes an organism undergoes throughout its life cycle?

    <p>Development</p> Signup and view all the answers

    Plants demonstrate _____, where juvenile leaves differ in shape from mature leaves.

    <p>heterophylly</p> Signup and view all the answers

    What type of growth curve characterizes living organisms growing in a natural environment?

    <p>Sigmoid curve</p> Signup and view all the answers

    In arithmetic growth, the length of the organ increases at a variable rate.

    <p>False</p> Signup and view all the answers

    Match the following developmental stages with their definitions:

    <p>Meristematic = Cells that actively divide Expansion = Increase in cell size Maturation = Cells taking on final form Senescence = The aging process leading to cell death</p> Signup and view all the answers

    What does the variable 'r' represent in the growth formula?

    <p>growth rate / elongation per unit time</p> Signup and view all the answers

    Which of the following plants exhibits heterophylly due to environmental factors?

    <p>Buttercup</p> Signup and view all the answers

    Cell division is the final stage in the development of a plant cell.

    <p>False</p> Signup and view all the answers

    The initial phase of growth that is slow due to limited cell division is known as the __________.

    <p>lag phase</p> Signup and view all the answers

    Match the growth phases with their characteristics:

    <p>Lag phase = Slow initial growth Exponential phase = Rapid growth increase Stationary phase = Growth rate plateau Sigmoid curve = Characteristic growth pattern of living organisms</p> Signup and view all the answers

    Name one factor that influences development in plants.

    <p>Intrinsic or extrinsic factors</p> Signup and view all the answers

    How is the formula for arithmetic growth expressed?

    <p>Lt = L0 + rt</p> Signup and view all the answers

    In the stationary phase, growth slows down due to unlimited nutrient supply.

    <p>False</p> Signup and view all the answers

    What type of growth rate is depicted in a linear curve?

    <p>arithmetic growth</p> Signup and view all the answers

    What is the primary role of ethylene in plants?

    <p>Enhancing fruit ripening</p> Signup and view all the answers

    Abscisic acid stimulates seed germination.

    <p>False</p> Signup and view all the answers

    Name one effect of ethylene on seedlings.

    <p>Horizontal growth</p> Signup and view all the answers

    Ethylene promotes rapid ________ elongation in deep water rice plants.

    <p>internode</p> Signup and view all the answers

    Match the following substances with their roles in plant growth:

    <p>Ethephon = Enhances fruit ripening and abscission Abscisic acid = Inhibits germination and promotes dormancy Ethylene = Induces flowering in mango Gibberellins = Promotes growth and elongation</p> Signup and view all the answers

    What is the effect of abscisic acid during stress conditions?

    <p>Stimulates stomatal closure</p> Signup and view all the answers

    The increased rate of respiration during fruit ripening is known as the ________ climactic.

    <p>respiratory</p> Signup and view all the answers

    Ethephon is a widely used source of abscisic acid in agriculture.

    <p>False</p> Signup and view all the answers

    What substance did F.W. Went isolate from the coleoptile tips?

    <p>Auxin</p> Signup and view all the answers

    The coleoptiles of canary grass exhibit phototropism.

    <p>True</p> Signup and view all the answers

    What disease in rice seedlings is caused by the fungal pathogen Gibberella fujikuroi?

    <p>Bakanae disease</p> Signup and view all the answers

    The active substance identified in the 'bakanae' disease of rice is ________.

    <p>gibberellic acid</p> Signup and view all the answers

    Match the following plant growth regulators with their identified effects:

    <p>Auxin = Promotes cell elongation Gibberellic acid = Stimulates stem elongation Cytokinins = Promotes cell division Abscisic acid = Inhibits growth during stress conditions</p> Signup and view all the answers

    Which of the following substances was later identified as a gaseous plant growth regulator?

    <p>Ethylene</p> Signup and view all the answers

    Kinetin was identified as a substance that inhibits cell division in plants.

    <p>False</p> Signup and view all the answers

    Who confirmed the release of a volatile substance from ripened oranges that hastened ripening of bananas?

    <p>H.H. Cousins</p> Signup and view all the answers

    What type of growth allows plants to increase in size indefinitely due to meristem activity?

    <p>Indeterminate growth</p> Signup and view all the answers

    Meristems lose their capacity to divide after producing new cells.

    <p>True</p> Signup and view all the answers

    What is the definition of growth in the context of plants?

    <p>An irreversible permanent increase in size of an organ or its parts.</p> Signup and view all the answers

    The __________ meristem is responsible for the elongation of plants along their axis.

    <p>apical</p> Signup and view all the answers

    Which of the following structures is responsible for increasing the girth of plant organs?

    <p>Vascular cambium</p> Signup and view all the answers

    Match the following types of growth with their definitions:

    <p>Indeterminate growth = Unlimited growth throughout life Determinant growth = Growth stops after a certain point Meristematic growth = Occurs at the apices of roots and shoots Secondary growth = Increase in girth of plant organs</p> Signup and view all the answers

    What happens to plant growth if the meristem ceases to divide?

    <p>Growth would stop.</p> Signup and view all the answers

    What is the primary characteristic of cells in the meristematic phase of growth?

    <p>Rich in protoplasm with large nuclei</p> Signup and view all the answers

    In plants, _____ are responsible for producing cells that contribute to growth.

    <p>meristems</p> Signup and view all the answers

    Cells in the maturation phase undergo significant elongation.

    <p>False</p> Signup and view all the answers

    What mathematical forms can growth rate take?

    <p>Arithmetic and geometric</p> Signup and view all the answers

    In the meristematic zone, the cells possess __________ cell walls that are thin and cellulosic.

    <p>primary</p> Signup and view all the answers

    Match the growth phases with their descriptions:

    <p>Meristematic = Constantly dividing cells Elongation = Cell enlargement and vacuolation Maturation = Maximal cell size and differentiation</p> Signup and view all the answers

    The cells in the elongation phase show abundant plasmodesmata connections.

    <p>True</p> Signup and view all the answers

    What is the primary activity occurring at the root and shoot apex?

    <p>Cell division</p> Signup and view all the answers

    Which of the following best describes development in plants?

    <p>It includes changes from germination to senescence.</p> Signup and view all the answers

    Heterophylly refers to the phenomenon where different leaves of a plant have the same shape throughout its life cycle.

    <p>False</p> Signup and view all the answers

    What is meant by plasticity in plant development?

    <p>The ability of plants to respond differently to environmental conditions.</p> Signup and view all the answers

    The final structure at maturity of a cell or tissue is influenced by its __________ within the organism.

    <p>location</p> Signup and view all the answers

    Match the following plant development terms to their descriptions:

    <p>Growth = Increase in size or mass Differentiation = Process where cells become specialized Senescence = A period of aging in plants Meristematic = Region of actively dividing cells</p> Signup and view all the answers

    What is an example of heterophylly?

    <p>Different leaf sizes in varying environmental conditions.</p> Signup and view all the answers

    The process of cell __________ involves cells reaching their full size through elongation.

    <p>maturation</p> Signup and view all the answers

    Name one factor that influences plant growth and differentiation.

    <p>Intrinsic factors or Extrinsic factors.</p> Signup and view all the answers

    Which of the following are characteristics of plant growth regulators (PGRs)?

    <p>They can be classified as plant hormones.</p> Signup and view all the answers

    Gibberellins are considered plant growth inhibitors.

    <p>False</p> Signup and view all the answers

    Name one type of plant growth regulator that is known to stimulate growth.

    <p>Auxins</p> Signup and view all the answers

    The gaseous plant growth regulator __________ is known for its role in both promoting and inhibiting growth activities.

    <p>ethylene</p> Signup and view all the answers

    Which of the following groups of PGRs primarily contributes to responses to biotic and abiotic stresses?

    <p>Abscisic Acid</p> Signup and view all the answers

    What are the two groups into which plant growth regulators can be broadly classified?

    <p>Growth promoters and inhibitors</p> Signup and view all the answers

    What is the primary effect of auxin in plant growth?

    <p>Promoting cell elongation</p> Signup and view all the answers

    Gibberella fujikuroi causes the 'bakanae' disease in rice seedlings.

    <p>True</p> Signup and view all the answers

    What compound was identified as the active substance from the fungus in the 'bakanae' disease?

    <p>Gibberellic acid</p> Signup and view all the answers

    The gaseous plant growth regulator ________ is known to hasten the ripening of fruits.

    <p>ethylene</p> Signup and view all the answers

    Match the following plant growth regulators with their respective functions:

    <p>Auxin = Cell elongation Cytokinin = Cell division Abscisic acid = Stress response Ethylene = Fruit ripening</p> Signup and view all the answers

    Which of the following is a characteristic of abscisic acid (ABA)?

    <p>Inhibits growth</p> Signup and view all the answers

    All inhibitors of plant growth regulators are chemically identical.

    <p>False</p> Signup and view all the answers

    Who is credited with isolating auxin from coleoptiles?

    <p>F.W. Went</p> Signup and view all the answers

    Which of the following is NOT a synthetic auxin?

    <p>Indole-3-acetic acid (IAA)</p> Signup and view all the answers

    Auxins are produced exclusively in the roots of plants.

    <p>False</p> Signup and view all the answers

    What phenomenon inhibits the growth of lateral buds in most higher plants?

    <p>Apical dominance</p> Signup and view all the answers

    Auxins promote flowering in _________.

    <p>pineapples</p> Signup and view all the answers

    What is one of the primary uses of gibberellins in plants?

    <p>Enhancing fruit development</p> Signup and view all the answers

    2, 4-D affects both dicotyledonous and monocotyledonous plants equally.

    <p>False</p> Signup and view all the answers

    What is one effect of auxins on the fruit development process?

    <p>Induction of parthenocarpy</p> Signup and view all the answers

    What is the term for the ability of plants to form different structures in response to their environment?

    <p>Plasticity</p> Signup and view all the answers

    Which parameter is indicative of the ability of a plant to produce new material?

    <p>Efficiency index</p> Signup and view all the answers

    Heterophylly is an example of how plants respond to changes in their environment.

    <p>True</p> Signup and view all the answers

    The absolute growth rate is defined as the growth of a system per unit time expressed on a common basis.

    <p>False</p> Signup and view all the answers

    What process marks the final stages of a plant cell's development?

    <p>Maturation</p> Signup and view all the answers

    What does the variable 't' represent in the exponential growth formula?

    <p>Time of growth</p> Signup and view all the answers

    The developmental pathway of a plant includes cell division, __________, differentiation, and senescence.

    <p>expansion</p> Signup and view all the answers

    Growth in plants primarily requires __________, oxygen, and nutrients.

    <p>water</p> Signup and view all the answers

    Which of the following is an example of heterophylly?

    <p>Cotton leaves changing shape from juvenile to mature</p> Signup and view all the answers

    Which of the following statements about leaves A and B is true?

    <p>One leaf showed a higher relative growth rate than the other.</p> Signup and view all the answers

    All plant cells differentiate the same way regardless of their location.

    <p>False</p> Signup and view all the answers

    Cell enlargement in plant growth does not require water.

    <p>False</p> Signup and view all the answers

    What are two factors that control development in plants?

    <p>Intrinsic and extrinsic factors</p> Signup and view all the answers

    What characterizes the cells in the meristematic phase of growth?

    <p>Thin cell walls with rich protoplasm and large nuclei</p> Signup and view all the answers

    What is the significance of the turgidity of plant cells in growth?

    <p>It helps in extension growth.</p> Signup and view all the answers

    In arithmetic growth, both daughter cells continue to divide after mitotic division.

    <p>False</p> Signup and view all the answers

    What is the term for the increased growth per unit time in an organism?

    <p>growth rate</p> Signup and view all the answers

    The cells in the region just proximal to the apex undergoing cell enlargement and wall deposition represent the phase of __________.

    <p>elongation</p> Signup and view all the answers

    Which of these statements is true regarding the growth rate?

    <p>Growth rate can be arithmetic or geometric.</p> Signup and view all the answers

    Cells in the maturation phase have begun the process of cell wall thickening.

    <p>True</p> Signup and view all the answers

    What occurs in the maturation phase of plant growth?

    <p>Cells achieve maximal size and undergo protoplasmic modifications.</p> Signup and view all the answers

    What is the primary function of gibberellic acid (GA3) in plants?

    <p>Delay senescence</p> Signup and view all the answers

    Cytokinins naturally occur in all plant parts.

    <p>False</p> Signup and view all the answers

    What effect does gibberellic acid have on the length of sugarcane stems?

    <p>Increases stem length</p> Signup and view all the answers

    Cytokinins help overcome __________ dominance.

    <p>apical</p> Signup and view all the answers

    Which plant growth regulator is primarily associated with increasing the maturity rate in juvenile conifers?

    <p>Gibberellins</p> Signup and view all the answers

    Kinetin is a naturally occurring cytokinin found in all plants.

    <p>False</p> Signup and view all the answers

    Name one natural source of cytokinins besides kinetin.

    <p>Zeatin from corn or coconut milk</p> Signup and view all the answers

    Which plant growth regulator is primarily known for regulating abscission and dormancy in plants?

    <p>Abscisic acid</p> Signup and view all the answers

    Plant growth is considered a reversible process.

    <p>False</p> Signup and view all the answers

    Name one extrinsic factor that influences plant growth.

    <p>Temperature or light</p> Signup and view all the answers

    Which plant growth regulator is commonly referred to as the stress hormone?

    <p>Abscisic Acid</p> Signup and view all the answers

    The three principal phases of growth are lag, log, and __________.

    <p>senescent</p> Signup and view all the answers

    All plant growth regulators have the same physiological effects on plants.

    <p>False</p> Signup and view all the answers

    Which of the following factors is NOT an intrinsic factor in plant growth?

    <p>Soil nutrients</p> Signup and view all the answers

    The type of growth characterized by an increase in size that can be represented by a straight line on a graph is called __________ growth.

    <p>arithmetic</p> Signup and view all the answers

    Growth in plants is typically measured only by the increase in dry weight.

    <p>False</p> Signup and view all the answers

    What is the role of meristems in plant growth?

    <p>Sites of growth for root and shoot elongation</p> Signup and view all the answers

    Study Notes

    Plant Growth and Development

    • Plant growth is an irreversible increase in size or parts
    • Plant growth is accompanied by metabolic processes (anabolic and catabolic)
    • Plant growth occurs at the expense of energy
    • Growth is measurable
      • Increase in fresh weight
      • Increase in dry weight
      • Increase in length
      • Increase in area
      • Increase in volume
      • Increase in cell number
    • Growth can be arithmetic or geometric
      • Arithmetic growth: One daughter cell divides, the other differentiates
      • Geometric growth: Both progeny cells continue to divide in a rapid manner
    • Growth rates can be expressed mathematically

    Phases of Growth

    • Meristematic: Cells actively divide, high protoplasm content, thin cell walls
    • Elongation: Cells enlarge, increase in vacuole size, cell wall deposition
    • Maturation: Cells reach maximal size, protoplasm modifications

    Plant Growth Regulators (PGRs)

    • Small molecules, diverse chemical compositions
    • Indole compounds (e.g., IAA)
    • Adenine derivatives (e.g., kinetin)
    • Derivatives of carotenoids (e.g., ABA)
    • Terpenes (e.g., gibberellic acid)
    • Gases (e.g., ethylene)

    Types of PGRs

    • Growth promoters: Auxins, gibberellins, cytokinins
    • Growth inhibitors: Abscisic acid, ethylene

    Physiological Effects

    • Auxins: Cell division, cell enlargement, differentiation, parthenocarpy, apical dominance
    • Gibberellins: Elongation of axis, increasing length of grapes, seed germination, breaking bud dormancy
    • Cytokinins: Cell division, cell enlargement, delay of leaf senescence, overcoming apical dominance
    • Ethylene: Fruit ripening, abscission of leaves and flowers, breaking seed/bud dormancy
    • Abscisic acid: Growth inhibitor, seed dormancy, stomatal closure, stress response

    Development

    • Includes all changes in an organism throughout its life cycle
    • Consists of germination, processes and senescence

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    Plant Growth and Development PDF

    Description

    This quiz explores the essentials of plant growth, covering various phases such as meristematic, elongation, and maturation. It also includes the role of plant growth regulators and the factors that influence growth rates. Enhance your understanding of how plants develop and what processes are involved in their growth.

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