Plant growth and development Flashcards
______________ is the sum of growth and differentiation
Development
The first step in the process of plant growth is
Seed germination
The most fundamental and conspicuous characteristic of living being is
Growth
Plants retain capacity for unlimited growth throughout their life due to the presence of _____________
Meristems
The form of growth wherein new cells are always being added to the plant body by the activity of the meristem is called _____________ form of growth.
Open
Root and shoot meristem are responsible for __________ growth of plants
Primary
Lateral meristems appear later in life in __________ and ____________
Dicots and gymnosperms
The two lateral meristems are _______________ and _________________
Vascular and cork cambium
The meristems that cause increase in girth of organs are known as
Lateral meristems (vascular cambium and cork-cambium)
Lateral meristems are responsible for _________ growth of plant
Secondary
Increase in fresh weight, dry weight, length, area, volume and cell number are parameters for measuring increase in
Growth
One single maize root apical mersitem can give rise to more than ________ new cells per hour
17500
Growth of pollen tube is measured in terms of ____________
Length
Growth of dosriventral leaf is measured in terms of _________
Surface area
The period of growth is divided into three phases, namely
Meristematic, elongation and maturation
Abundant protoplasm, large nuclei and primary nature of walls are charateristic of cells undergoing ____________ growth
Meristematic
Increased vacuolation, cell enlargement and new cell wall deposition are the characteristics of the cells in which phase of growth?
Elongation
Cells in their maximum size correspond to which phase of growth?
Maturation
The increased growth per unit time is called
Growth rate
In which type of growth following mitotic cell division, only one daughter cell continues to divide while the other differentiates and matures?
Arithmatic
Root elongation at constant rate is an example of
Arithmetic growth
The curve of arithematic growth comes out to be __________
Linear
In most systems, the initial growth is slow(lag phase), and it increases rapidly thereafter – at an exponential rate (____________).
log or exponential phase
The growth in which both the progeny of cells following mitotic cell division retain the ability to divide and continue dividing is
Geometrical growth
The exponential growth in plants slows down due to _____________
Limited nutrient supply
A ______ curve is a characteristic of living organism growing in a natural environment.
Sigmoid
The curve which is a characteristic of living organism growing in a natural environment is
Sigmoid
r’ in exponential growth expression represents
Relative growth rate
Lag and stationary phases are characteristics of ___________ growth
geometric
What is measure of efficiency index in exponential growth expression?
Relative growth rate
Measurement and the comparison of total growth per unit time is called
Absolute growth rate
The growth of the given system per unit time expressed on a common basis is called
Relative growth rate
Plant cells grow in size by ________
Cell enlargement
Turgidity of cells helps in growth by ______
Extension
The three most essential elements for plant growth are
Water, oxygen and nutrients
Oxygen helps in releasing ________ energy essential for growth activities
metabolic
________ are required by plants for energy and synthesis of protoplasm
Nutrients
The two environmental signals that affect certain phases of plant growth are
Light and gravity
The process of maturation of cells derived from meristems and cambium to perform specific functions is called
Differentiation
In order to form a tracheary element, cell will lose its
Protoplasm
Secondary cell walls of tracheary elements are composed of
Lignocellulose
The living differentiated cells, that have lost the capacity to divide can regain the capacity of division under certain conditions, the process is called
Dedifferentiation
An example of dedifferentiation in plants is
Formation of meristems – interfascicular cambium and cork cambium from fully differentiated parenchyma cells.
Formation of interfascicular cambium from parenchyma cells is an exmaple of
Dedifferentiation
During dedifferentiation, when meristems are able to divide and produce cells that once again lose capacity to divide but then mature to perform specific functions is known as
Redifferentiation
The cells positioned away from root apical meristem differentiate as _____________
Root cap cells
The process that includes all changes that an organism goes through during its life cycle from germination of the seed to senescence is called
Development
The ability of plants to follow different pathways in response to environment or phases of life to form different kinds of structures is called
Plasticity
Heterophylly in cotton, coriander and larkspur is an example of
Plasticity
In buttercup, difference in shapes of leaves produced in air and in water is an example of
Heterophylly/plasticity
Plant development is considered as the sum of its
Growth and differentiation
Name the extrinsic factors affecting plant development
Light, temperature, water, oxygen, nutrition
PGRs stand for
Plant growth regulators
An indole containing PGR is
Indole-3-acetic acid
A PGR with adenine derivative is
Kinetin/N6-furfurylamino purine
A PGR which is derivative of carotenoid is
Abscisic acid
PGR composed of terpenes is
Gibberellic acid
Name a gaseous PGR
Ethylene
The PGRs which are involved in growth promoting activities are called
Plant growth promoters
Name three plant growth promoters
Auxins, Gibberrelins, Cytokinins
A gaseous plant growth regulator which inhibits growth activities is
Ethylene
The PGR playing an important role in plant responses to wounds and stresses of biotic and abiotic origin is
Abscisic acid
The discovery of PGRs started with observations of Charles Darwin and his son on unilateral illumination of ____________ by growing towards light source
Coleoptile
Auxin was isolated by which scientist from tips of coleoptiles of oat seedlings
F.W. Went
The ‘bakanae’ (foolish seedling) disease of rice seedlings, was caused by a fungal pathogen
Gibberella fujikuroi
The active substances held responsible for causing bakanae in rice seedlings was
Gibberelins
Cytokinesis promoting active substance discovered by Miller was termed -
Kinetin
Inhibitor-B, abscission II and dormin were chemically identified same and named as
Abscisic acid
The presence of ethylene was first confirmed by
H. H. Cousins
Auxin was isolated for the first time from ________
Human urine
IAA stands for
Indole-3-acetic acid
The PGR produced by growing apices of stems and roots is
Auxins
Name two natural auxins
Indole-3-acetic acid and Indole butyric acid
Name two synthetic auxins
Naphthalene acetic acid and 2, 4-dichlorophenoxyacetic
Auxins promote flowering in which fruit?
Pineapples
The PGR that helps to prevent fruit and leaf drop at early stages but promote the abscission of older mature leaves and fruits is __
Auxin
In agricultural practices, ___________ is used to initiate rooting in stem cuttings
Auxins
The phenomenon of growing apical bud inhibiting the growth of the lateral buds is called
Apical dominance
Removal of shoot tips is called
Decapitation
The technique widely applied in tea plantations and hedge making is
Decapitation
Parthenocarpy in tomato is induced by
Auxins
The PGRs widely used as herbicides are
Auxins
Auxin used to kill dicot weeds is
2, 4-D
Auxin is responsible for controlling differentiation of which vascular tissue?
Xylem
The PGR that has been known to exist in more than 100 forms in fungi and plants is
Gibberelins
The first discovered gibberelic acid was
GA3
The PGR employed to increase length of grape stalk due to its capability of increasing axis length is
Gibberelins
The PGR used to delay senescence and speed up the malting process is
Gibberelins
Increase in length of sugarcane to produce more sugar can be done by spraying crops with ____________
Gibberelins
Gibberelins can induce early seed production in
Conifers
The process of internode elongation just prior to flowering is called
Bolting
Bolting in beet and cabbages can be induced by application of
Gibberrelins
Kinetin was discovered from
Herring sperm DNA
Kinetin is modified form of which purine?
Adenine
Cytokinins show specific effects during which step of cell division?
Cytokinesis
The PGR that helps in production of new leaves, chloroplasts, lateral shoot growth and adventitious shoot formation is
Cytokinins
The hormone that helps overcome apical dominance is
Cytokinins
Cytokinins promote nutrient mobilisation which helps in delay of
Leaf senescence
The gaseous PGR synthesised in large amounts in tissues undergoing senescence is
Ethylene
Tissues undergoing fruit ripening will possess large amounts of PGR
Ethylene
Horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot seedlings is promoted by PGR
Ethylene
Ethylene promotes sensescence and abscission of plant organs especially of ____________ and ___________
Leaves and flowers
The characteristic function of ethylene is
Promotion of fruit ripening
Ethylene promotes fruit ripening by enhancing the
Respiration rate
The rise in rate of respiration during fruit ripening is called
Respiratory climactic
Ethylene initiates germination in
Peanut seeds
Ethylene promotes rapid ___________________ in deep water rice plants
Internode/petiole elongation
The PGR involved in sprouting of potato tubers is
Ethylene
Ethylene also promotes root growth and root hair formation, thus helping the plants to increase their _______ surface
absorption
Ethylene initiates flowering and synchronises fruitset in ______________
Pineapples
Flowering in mango is induced by PGR -
Ethylene
The most widely used PGR in agriculture is
Ethylene
The most widely used compound as source of ethylene is
Ethephon
The type of ethylene hastening fruit ripening in tomatoes and apples is
Ethepon
In cucumber, ethylene promotes
Female flowering
The hormone discovered for its role in regulating abscission and dormancy is
Abscissic acid
The PGR acting as general plant growth inhibitor is
Abscissic acid
ABA inhibits ________ and __________
Plant metabolism and seed germination
The PGR increasing tolerance to various kinds of stresses is
ABA
ABA stimulates _________ of stomata
Closure
ABA is commonly known as _______ hormone of plants
Stress
Hormone playing an important role in seed development, maturation and dormancy is
ABA
ABA acts as an antagonist to
Gibberelic acid
The plants which require exposure of light for period exceeding critical duration are called
Long day plants
In plants, where there is no correlation between duration of sunlight exposure and induction of flowering response are called
Day-neutral plants
The response of plants to periods of day/night is termed as
Photoperiodism
The site of perception of light/dark in plants are
Leaves
The phenomenon when flowering of plants is either quantitatively or qualitatively dependent on exposure to low temperature is termed as
Vernalisation
Name three important food plants having two varieties, winter and spring
Wheat, rye, barley
Vernalisation is exhibited by _____________ plants
Biennial
Name three biennial plants
Sugarbeet, cabbage, carrot
Subjecting the growing of a biennial plant to a ________ treatment stimulates a subsequent photoperiodic flowering response
Cold
The quality of seed coat that inhibits germination is
Impermeable and hard seed coat
The three chemical inhibitors in seed preventing its germination are
ABA, Phenolic acid, Para-ascorbic acid
Effect of inhibitory chemicals on seed can be removed by subjecting seeds to _________________
Chilling conditions
Application of which chemicals can help dormant seed overcome the effect of inhibitory chemicals
Gibberrelic acid and nitrates
Seed dormancy can be overcome by changing environmental conditions like
Light and temperature
Barrier in seed coat that prevent it from germinating can be broken by
Mechanical abrasions
Two means of natural seed abrasion are
Microbial action and passage through digestive tract of animals
