growth &dev

7/21/2019 Growth &Dev

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PLANT GROWTH ANDPLANT GROWTH ANDDEVELOPMENT DEVELOPMENT



1.1. Do all of organisms grow and develop?Do all of organisms grow and develop?

2.2. Do the growth and development different?Do the growth and development different?

Explain your answer.Explain your answer.3.3. Mention 3 examples of growth and development.Mention 3 examples of growth and development.

4.4. Why do plant ale to grow?Why do plant ale to grow?

!.!. Do you "now aout determinate andDo you "now aout determinate andindeterminate growth ? #lease explain yourindeterminate growth ? #lease explain your

opinion.opinion.

$.$.

%rowth was influen&ed y internal dan external%rowth was influen&ed y internal dan external

fa&tor. #lease mention them.fa&tor. #lease mention them.



Growth and DevelopmentGrowth and Development

Higher Plants…multicellular organismsHigher Plants…multicellular organisms

whose growth is characterized by increaseswhose growth is characterized by increases

in bothin both bulk bulk andand complexitycom

plexity

Events associated with increases in size andEvents associated with increases in size and

complexity can be divided into interrelatedcomplexity can be divided into interrelatedprocesses: growth and developmentprocesses: growth and development



GROWTHGROWTH

Growth can be defined as anGrowth can be defined as anirreversible er!anent increase in si"eirreversible er!anent increase in si"e

of an or#an or its arts or even of anof an or#an or its arts or even of anindivid$al cell%individ$al cell%

Growth is acco!anied b& !etabolicGrowth is acco!anied b& !etabolicrocesses' that occ$r at the e(ense ofrocesses' that occ$r at the e(ense of

ener#&%ener#&% )or e(a!le' e(ansion of a leaf is)or e(a!le' e(ansion of a leaf is

#rowth%#rowth%



DEVELOPMENT DEVELOPMENT

Develo!ent is a ter! that incl$des allDevelo!ent is a ter! that incl$des all

chan#es that an or#anis! #oes tro$#hchan#es that an or#anis! #oes tro$#hits life c&cle fro! #er!ination of theits life c&cle fro! #er!ination of theseed to senescenceseed to senescence..



Growth vs DevelopmentGrowth vs Development

GrowthGrowth uantitativeuantitative

!umber" size" and!umber" size" and

volume increasevolume increase

DevelopmentDevelopment ualitativeualitative

Emergence o#Emergence o#

specialized bodyspecialized body

partsparts



Growth and DevelopmentGrowth and Development

GrowthGrowth: irreversible increase in size $net: irreversible increase in size $netincrease in protoplasm% brought about byincrease in protoplasm% brought about by

increases in cell size and number&increases in cell size and number&

DevelopmentDevelopment: which includes…: which includes… 'orphogenesis'orphogenesis: creation o# pattern and shape: creation o# pattern and shape

resulting inresulting in morphological and anatomicalmorphological and anatomical

development&development&

Di##erentiationDi##erentiation: physiological and biochemical: physiological and biochemical

specializations&specializations&



Plant growth is measurablePlant growth is measurable

Growth is !eas$red b& a variet& ofGrowth is !eas$red b& a variet& ofara!eters so!e of which are *ara!eters so!e of which are *

a+ ,ncrease in fresh wei#hta+ ,ncrease in fresh wei#ht

b+ Dr& wei#htb+ Dr& wei#ht

c+ Len#thc+ Len#th

d+ Aread+ Area

e+ Vol$!ee+ Vol$!e

f+ -ell N$!berf+ -ell N$!ber



geneti&ally determined life spans 'most(geneti&ally determined life spans 'most(

annualsannuals

perennials perennials

plants exhiit plants exhiit )) indeterminate growth*indeterminate growth*

determinate growthdeterminate growth

two types of growth)two types of growth) primary and primary and

se&ondaryse&ondary

GrowthGrowth



(i#e spans(i#e spans



patterns o# growthpatterns o# growth



)ype o# growth)ype o# growth



Phases of GrowthPhases of Growth

The eriod of #rowth is #enerall&The eriod of #rowth is #enerall&divided into three hases' na!el& *divided into three hases' na!el& *

a+ Meriste!atica+ Meriste!aticb+ Elon#ationb+ Elon#ation

c+ Mat$rationc+ Mat$ration



'eristematic phase'eristematic phase

%rowth in plants is restri&ted to &ertain +ones)%rowth in plants is restri&ted to &ertain +ones)

meristemmeristem

,ell always divide,ell always divide



ElongationElongation

&ellular produ&t of division do grow and &ause&ellular produ&t of division do grow and &ause

in&reasing of si+ein&reasing of si+e



Maturation : D!!ERENT"TON#Maturation : D!!ERENT"TON#DED!!ERENT"TONDED!!ERENT"TON

D,))ERENT,AT,OND,))ERENT,AT,ON. The cells derived fro!. The cells derived fro!root aical / shoot aical !eriste!s /root aical / shoot aical !eriste!s /ca!bi$! differentiate / !at$re to erfor!ca!bi$! differentiate / !at$re to erfor!secific f$nctions% This act leadin# tosecific f$nctions% This act leadin# to!at$ration is ter!ed as differentiation%!at$ration is ter!ed as differentiation%

DED,))ERENT,AT,ONDED,))ERENT,AT,ON. The livin#. The livin#

differentiated cells' that b& now have lostdifferentiated cells' that b& now have lostthe caacit& to divide can re#ain the caacit&the caacit& to divide can re#ain the caacit&of division $nder certain conditions% Thisof division $nder certain conditions% Thisheno!enon is ter!ed as dedifferentiation%heno!enon is ter!ed as dedifferentiation%



!ate of stem $ells% remain as stem $ells or &ifferentiate to other $ells



*oot Growth*oot Growth

#rimary growth divided into three +ones)#rimary growth divided into three +ones)

1.1. ,ell division,ell division) api&al meristem* this) api&al meristem* thisdifferentiates into)differentiates into) protoderm, procambium, protoderm, procambium,

and ground meristemand ground meristem 'primary tissues('primary tissues(

2.2. ,ell elongation,ell elongation) elongate at least 1-*) elongate at least 1-* pushes tip through the soil pushes tip through the soil

3.3. MaturationMaturation) &ells &omplete their) &ells &omplete theirdifferentiationdifferentiation



Primary )issues in the *ootPrimary )issues in the *oot

ProtodermProtoderm) outermost layer of primary meristem*) outermost layer of primary meristem*

give rise to epidermis* many with root hairsgive rise to epidermis* many with root hairs

ProcambiumProcambium) forms stele '&entral &ylinder() forms stele '&entral &ylinder(

&ontaining xylem and phloem*&ontaining xylem and phloem* Ground meristem:Ground meristem: &ortex etween stele and&ortex etween stele and

epidermis* pare&hyma &ells* stores food* endodermisepidermis* pare&hyma &ells* stores food* endodermis

single &ell layer oundary etween &ortex and stele*single &ell layer oundary etween &ortex and stele*

peri&y&le inside endodermis peri&y&le inside endodermis



Primary Growth o# +temsPrimary Growth o# +tems

/pi&al meristem forms primary meristems/pi&al meristem forms primary meristems

'protoderm* ground meristem* and'protoderm* ground meristem* and

pro&amium( pro&amium(

#ro&amium forms vas&ular tissue in undles#ro&amium forms vas&ular tissue in undles

%round meristem forms pith and &ortex%round meristem forms pith and &ortex

#rotoderm forms epidermal tissues#rotoderm forms epidermal tissues



(ea# Growth(ea# Growth

%round tissues form the mesophyll%round tissues form the mesophyll

pro&amium forms the veins pro&amium forms the veins

#rotoderm forms the upper and lower#rotoderm forms the upper and lowerepidermis* guard &ells waxy &uti&leepidermis* guard &ells waxy &uti&le



Growth RatesGrowth Rates

The increased #rowth er $nit ti!e isThe increased #rowth er $nit ti!e ister!ed as #rowth rateter!ed as #rowth rate

Rate of #rowth can be e(ressedRate of #rowth can be e(ressed!athe!aticall&%!athe!aticall&%



Growth kineticsGrowth kinetics

0'sigmoid(shapes growth &urve0'sigmoid(shapes growth &urve

3 phases )3 phases )

ogaritmi& phaseogaritmi& phase inier phaseinier phase

0enes&ense phase0enes&ense phase

H,'E-,*. : explain the mechanism o#H,'E-,*. : explain the mechanism o#

all phases" complete with #igureall phases" complete with #igure



)opics)opics

%rowth fa&tors '4 des(%rowth fa&tors '4 des(

%rowth regulators phytohormones '4 des(%rowth regulators phytohormones '4 des(

0eed germination '11 des(0eed germination '11 des( #lant movements '11 des(#lant movements '11 des(

#hotoperiodism ' ?(#hotoperiodism ' ?(

0enes&en&e '?(0enes&en&e '?(

growth &dev

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