6. CONDITIONS FOR GROWTH
Water: For cell enlargement. Turgidity of
cells helps in extension growth. Water
provides medium for enzymatic activities
needed for growth.
Oxygen: It helps to release
metabolic energy for growth.
Nutrients: Macro & micro
elements are needed for the
synthesis of protoplasm and
act as source of energy.
Temperature: Plants have an optimum
temperature at which growth is maximum.
Deviation from this range could be
detrimental to its survival.
Light & gravity: Affect certain
phases/stages of growth.
7. DIFFERENTIATION, DEDIFFERENTIATION
& REDIFFERENTIATION
Differentiation is a process in which the
meristem cells (root apical & shoot-apical)
and cambium differentiate and mature to
perform specific functions.
In this, cell walls & protoplasm undergo
structural changes. Capacity of cell
division is lost. E.g. Loss of protoplasm to
form a tracheary element.
They also develop very strong, elastic,
lignocellulosic secondary cell walls, to
carry water to long distances even under
extreme tension.
8.
9. DIFFERENTIATION, DEDIFFERENTIATION
& REDIFFERENTIATION
Under certain conditions, living
differentiated cells regain the
capacity of division. This is called
dedifferentiation.
E.g. formation of meristems
(interfascicular cambium & cork
cambium) from differentiated
parenchyma cells.
Dedifferentiated cells can produce cells
that again lose the capacity to divide but
mature to perform specific functions. It
is called redifferentiation.
10. PLASTICITY
Plants follow different pathways in response to environment or phases of life to form
different kinds of structures. This ability is called plasticity.
Heterophylly due to phases of life:
● In cotton, coriander and larkspur, the
leaves of the juvenile plants and mature
plants are different in shape.
Heterophylly due to environment:
● E.g. Difference in shapes of leaves produced
in air and water (e.g. buttercup).
12. External Growth Factors
Light – Light is one of the most crucial
components of photosynthesis in plants.
Temperature – Every organism needs a
suitable temperature to survive, to grow,
to develop various tissues & organs, to
reproduce
Water – Plants absorbs water through
their roots and use it for photosynthesis
and other biochemical processes.
Mineral Nutrients – Other than light, water,
and a perfect temperature, organisms need
special nutrients to support their food
making process and metabolism, which
ultimately boosts growth in them.
13. Internal Growth Factors
Plants contain hormones
called – Auxins,
Gibberellins, Cytokinins,
Ethylene, Abscisic acid.
called growth regulators
14. PLANT GROWTH AND DEVELOPMENT
Plant growth regulators are of diverse chemical compositions that function in low
concentration and regulate plant growth, differentiation and development. Plant
hormones or phytohormones are a type of PGR.
PHYTOHORMONES
GROWTH PROMOTERS GROWTH INHIBITORS
● Abscisic acid
● Ethylene
● Auxins,
● Gibberellins
● Cytokinins
15. AUXIN
Plant Growth Regulators
Plant Growth Promoters Plant Growth Inhibitors
● For growth promoting activities like cell
division & enlargement, tropic growth,
pattern formation, flowering, fruiting &
seed formation.
● E.g. Auxins, gibberellins & cytokinins.
● For growth inhibiting activities like
dormancy & abscission. Respond to
wounds & stresses of biotic & abiotic
origin.
● E.g. abscisic acid & ethylene.
16. AUXIN
Term auxin refers to any chemical that
promotes elongation of coleoptiles
Indoleacetic acid (IAA) is a common
auxin in plants Auxin is produced in
shoot tips and is transported down the
stem Auxin transporter proteins move
hormone from basal end of one cell
into apical end of neighboring cell
17. AUXIN
Auxins are weakly acidic growth hormone having an unsaturated ring structure.
Indole 3 - acetic acid (IAA),
Phenyl acetic acid (PAA),
Indole 3- acetonitrile (INA)
(Indole 3-butyric acid, NAA, 2, 4-D,
2, 4, 5-T) compounds having
similar structure and properties.
NATURAL SYNTHETIC
18. AUXIN FUNCTION
According to the acid growth hypothesis, auxin stimulates proton pumps in the plasma membrane.
The proton pumps lower the pH in the cell wall, activating expansins, enzymes that loosen the wall’s
fabric. With the cellulose loosened, the cell can elongate
19. ✓ Establishes the apical-basal
polarity of seed embryos
✓ Induces vascular tissue to
differentiate
✓ Mediates phototropism
✓ Promotes formation of
adventitious roots
✓ Stimulates fruit development
✓ Used for cloning in plant
tissue culture
20.
21. ✓ To initiate rooting in stem cuttings
for plant propagation.
✓ Promote flowering. E.g. in pineapples.
✓ Induce parthenocarpy, e.g., in
tomatoes.
✓ They are used as herbicides. 2, 4-D is
used to kill dicot weeds.
✓ It does not affect monocot plants. It
is used to prepare weed-free lawns.
Auxin: High
Cytokinin: Low
Auxin: Low
Cytokinin: High
22. ● To prevent fruit and
leaf drop at early
stages.
● Promote the
abscission of older
leaves & fruits.
AUXIN FUNCTION
23. ● In higher plants, the growing apical bud inhibits the growth of lateral (axillary) buds.
● It is known as apical dominance.
● Removal of shoot tips (decapitation) results in the growth of lateral buds.
● It is applied in tea plantations, hedge-making.
AUXIN FUNCTION
24. A Jeffrey pine tree. The trunk of this tree,
which would normally be single, is forked
because of the earlier removal of the
terminal bud, allowing a lateral bud to
grow.
25. ● In rice plants, a disease called ‘bakanae’ disease or
foolish seedling caused by the fungus Gibberella
fujikuroi resulted in plants that grew overly tall
and spindly.
● Gibberellic acid made by the fungus caused rice
plants to overgrow.
● Later it was found that plants also make
gibberellic acid, and that applying it to plants
caused growth.
● There are more than 100 gibberellins (GA1, GA2,
GA3 etc.) in fungi and higher plants.
GIBBERELLINS
26. ● Gibberellins have a variety of effects, such as stem elongation, fruit growth,
and seed germination
GIBBERELLINS FUNCTIONS
27. ● Gibberellins stimulate growth of leaves and
stems
● In stems, they stimulate cell elongation and
cell division
● They cause increase in length of axis.
Stem Elongation
● So they are used to increase the length of
grapes stalks.
● Sugarcane stores sugar in stems.
● Spraying sugarcane crop with gibberellins
increases the length of the stem.
28. ● In many plants, both auxin and
gibberellins must be present for fruit
to develop
● Gibberellins are used in spraying of
Thompson seedless grapes
● To elongate and improve the shape
of fruits such as apple.
● They delay senescence. So the fruits
can be left on the tree to extend the
market period.
Fruit Growth
29. ● GA3 is used to speed up malting process
in brewing industry.
● Spraying juvenile conifers with GAs
hastens the maturity period. It leads to
early seed production.
● For bolting (internode elongation just
prior to flowering) in beet, cabbages and
many plants with rosette habit.
BOLTING
Rosette form (left) and gibberellin-induced
bolting (right)
30. ● Cytokinins are so named because they stimulate cytokinesis (cell division)
● Cytokinins were discovered as kinetin by F. Skoog and co-workers, it does not occur
naturally in plants.
CYTOKININS
31. ● Zeatin (from corn-kernels & coconut
milk) is the natural substances with
cytokinin-like activities.
● There are some synthetic compounds
with cell division promoting activity.
● Natural cytokinins are synthesized in
regions of rapid cell division (root
apices, shoot buds, young fruits etc).
32. • Cytokinins are produced in actively growing
tissues such as roots, embryos, and fruits
• Cytokinins work together with auxin to control
cell division and differentiation
CONTROL OF CELL DIVISION AND DIFFERENTIATION
33. • Cytokinins, auxin, interact in the control of apical
dominance, a terminal bud’s ability to suppress
development of axillary buds
• If the terminal bud is removed, plants become
bushier
Control of Apical Dominance
34. ● Plants produce ethylene
in response to stresses
such as drought, flooding,
mechanical pressure,
injury, and infection
● The effects of ethylene
include response to
mechanical stress,
senescence, leaf
abscission, and fruit
ripening
ETHYLENE
35. ● It influences horizontal growth of seedlings,
swelling of axis and apical hook formation in
dicot seedlings.
● It promotes senescence and abscission of plant
organs especially of leaves and flowers.
● It promotes fruit ripening. It enhances
respiration rate during fruit ripening. This is
called respiratory climactic.
● It breaks seed and bud dormancy, initiates
germination in peanut seeds, sprouting of
potato tubers.
ETHYLENE FUNCTION
36. ● Help plants respond to
environmental stresses such
as flooding, drought, high
salinity, cold, heat, and attack
by microorganisms and
herbivores
● Stimulates formation of
protective scales around buds
of perennial plants in
preparation for winter
ABSCISIC ACID (ABA)
37. ● It acts as an inhibitor of plant
growth & metabolism.
● It inhibits seed germination.
● It stimulates closure of stomata in
the epidermis.
● It has an important role in seed
development, maturation and
dormancy.
● Seed dormancy by ABA helps to
withstand desiccation and other
factors unfavourable for growth.
ABSCISIC ACID (ABA)
Guard cells (Swollen) Guard cells (Shrunken)
Stoma Opening Stoma Closing
38. ● After water is imbibed, release of gibberellins from the embryo signals seeds to germinate
GERMINATION
40. NEET
GRADE 12
1 YEAR
SUBJECTS
LANGUAGE WITHIN
VARIANT
CHAPTERWISE /MICRO
COURSES
CRASH /REVISION
JAN-FEB
PHY /CHEM /BIO ENGLISH /HINDI UNLIMITED
YES
COMPLEMENTARY - CBSE + NEET + KVPY CRASH COURSE
GRADE 11
1 YEAR
PHY /CHEM /BIO ENGLISH /HINDI UNLIMITED YES
2 YEARS COURSE DETAILS
41. SESSIONS PER WEEK DURATION OF EACH SESSION
10
8
2 hrs
2 hrs
GRADE 11
1 YEAR
GRADE 12
1 YEAR
VANI MA’AMS CLASSES
SESSIONS DETAILS
42. NUMBER OF BOOKS
14
13
ENGLISH
MEDIUM OF BOOKS MODE- PHYSICAL / E - BOOKS
ENGLISH
PHYSICAL BOOK &
CHAPTER WISE
VIDEOS-QR CODE
PHYSICAL BOOK &
CHAPTER WISE
VIDEOS-QR CODE
MORE THAN 10K Q&A WITH
SOLUTION VIDEOS-VIA QR CODE
GRADE 11
1 YEAR
GRADE 12
1 YEAR
TATVA BOOKS DETAILS
43. GRADE - 11 GRADE - 12
NO. OF TESTS
PARTWISE
FULL SYLLABUS
10 10
20 20
10 10
ASSIGNMENT AFTER EACH SESSION - OBJECTIVE
FREQUENCY OF TEST
E.G
#WEEKLY
1 TEST EVERY 15 DAYS 1 TEST EVERY 15 DAYS
PRACTICE TESTS
44. BATCH DETAILS
GRADE 11
1 YEAR
GRADE 12
1 YEAR
SECTION SIZE- CT (LOWEST TOUCH POINT)
150
150
PERSONALISED ATTENTION OF CT
45. IN - CLASS DOUBT
POST CLASS - VIA CHAT
DOUBT TIME NO. OF DOUBTS
8:00 AM - 11:00 PM 50 PER DAY
48. NEET - SUBSCRIPTION PRICES
TOTAL PRICE - 1350/month
8 hrs x 2 hrs = 16 hrs/week
4 weeks 16 hrs x 4 = 64 + 12 = 76 hrs
1350/rs
76 hrs
3 hrs x 2 = 6 hrs x 2 = 12 hrs
1 test in every 15 day
2 Test/month
49. NEET - SUBSCRIPTION PRICES
Doubt 15 hrs x 30 = 450 hrs
8:00 am to 11:00 am
450 hrs + 76 = 526 1350/rs
526
= 2.56Rs/hrs
50. Sometimes cytokinins can
be used against the plant by a pathogen.
In this case, Agrobacterium tumefaciens
(a bacterium) has incorporated a piece of
its DNA into the plant genome. This DNA
contains genes coding for enzymes
necessary for cytokinin and auxin
biosynthesis. The increased levels of these
hormones in the plant cause massive cell
division and the formation of a tumor.
CROWN GALL TUMOR
51. Answer in the comment section
Q. Apical dominance is caused by
A
B
Abscisic acid in lateral bud
Cytokinin in leaf tip
D
C
Auxin in shoot tip
Gibberellin in lateral buds
