Botany Class 11

8/9/2019 Botany Class 11

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ELL

The cell is defnes as living unit of life or basic unit of life or structural and functional unit of life or fundamental unit of life or autonomous and self contained unit of the life .

In 1665, Robert Hook discovered cell. In his experiment, he cut the cork pieces. Then he observed under

his microscope and ound man small compartments in it. He named each compartment !ell.In 1"#", $erman %otanist Schleiden occluded that the plant bod is also composed o cells. In addition,in 1"#& $erman 'oolo(ist Theodor concluded that the animal bod is also composed o cells.

Why cell is considered as basic unit of life or why cell is called self contained or autonomousunit?

The cell is smallest unit o li e. ) sin(le cell can per orm di*erent li e processes as it can di(est ood,respire, excrete, reproduce, and (ro+. The cell carries di*erent metabolic activities. The bod unction isout come o the di*erent activities o the cell. o the cell is considered as basic unit or sel contained orautonomous unit o li e.

!ell Theor• chleiden in 1"#" and ch+ann proposed cell theor in 1"#&. It states that•

!ell is a mass o protoplasm containin( nucleolus and is bounded b a membrane.• )ll the cells are similar in chemical composition and metabolic activities.• -ivin( thin(s are composed o cells• The unction o or(anisms is the outcomes o cell activities and interaction o cell components.

Objection of cell theory• %acteria and c an bacteria do no contain nucleus• ome un(i contain man nuclei in branched bod• There is no cellular or(ani ation in virus

To include all the livin( or(anisms the cell theor proposed b cleidan and ch+ann can be modifed+hich is called cell principle• !ell is a mass o protoplasm containin( nucleus or in lack o nucleus nuclear materials is taken• -ivin( thin(s are made up o cells• !ell can store (enetic in ormation and express rom (eneration to (eneration• !ell sometimes assume orms, +hich no lon(er have all the characteristics o the cell.

What is cellular totipotency /ven a sin(le cell o a plant bod has a po+er to re(enerate entireplant bod . This is called cellular totipotenc .In 1&50, te+ard conducted an experiment on carrot.In this experiment, He removed small piece o carrot phloem, kept thepiece in li uid medium. 2hloem cells divided producin( cell clusters.

The clusters are kept on solid medium, a ter e+ da s a plant (re+ in it.

Di erence between unicellular and multicellular

organismsIn unicellular or(anisms the bod is sin(le cell, sin(le cell per orm allthe li e activities, !ells are lar(er in si e, easil in ected and susceptible or dama(e, Amoeba,Paramecium

In multicellular or(anisms, number o di*erent t pes o cells orms bod , the bod unction is outcome o the cellular activities o di*erent cells, cells are usuall smaller is si e, not easil susceptible to dama(e,hi(her plants and animals

ELL BIOLOGY


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Types of cells

There are t+o t pes o cells ound in or(anisms. The di*erences are as ollo+s.

STRU TURE OF EUKARYOTI ELLShape

The shape is variable like round oval irre(ular spherical elon(ated or tubular etcSize

The si e is also di*erent in unicellular or(anisms it ran(e rom 13m to 1 mm. in multicellularor(anisms it ran(e rom 14 1003m

Cell ComponentsCell wallIt is outermost la er o plant cell. It is a ri(id and protective la er. It is composed o di*erent la er

iddle lamella It is present bet+een the +alls o ad acent cells. It acts as cementin( materials bet+eent+o cells. It is made up o carboh drate, !a and 7(!rimary cell wall" It is ound on either side o middle lamella. It is made up o middle lamella. Itmade up o cellulose, hemi cellulose. It is thin elastic and permeable.Secondary cell wall" it is ound on inner side o primar cell +all. It is thick non4elastic and ri(id it ismade up o cellulose li(nin and pectin#unction of cell wallIt provides ri(idit to the cell. It protects the inner mass o the cell. 7aintain the shape o the cell.%alance the osmotic pressure. It helps in absorption o +ater.

Cell membrane The most important structure o the cell is its membrane, or it is the cell membrane that controlsand re(ulates +hat enters and leaves the cell. The cell membrane is made o t+o la ers o lipids,called a lipid bilayer . The lipid bilayer is made o lipids 8 ats9 and phosphates, normall calledphospholipids 2hospholipids have a polar end, and a non4polar end. In makin( membranes, thenon4polar ends o both la ers ace each other, +hile the polar end aces the outside and inside o thecell. There are t+o theories or model o cell membraneSandwich odelIn this, there are t+o la ers o protein outer and inner. In bet+een t+o protein la ers, there are t+ophospholipids la ers.

The heads o the phospholipids molecules ace to+ards protein la er and the tails to+ard the centre.

!ro$aryotic cell %u$aryotic cell

mall in si e 8ran(e rom 100410000nm9:suall (elatinous sheath is present!ell +all is made up o amino su(ar and

muramic acid.7esosome is present, the po+er house o the cell

;uclear membrane and nucleolus isabsent


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#luid osaic odelIn this model, there are # la ers, t+o la ers o protein and one la er o phospholipids. Thephospholipids are li uid in nature. There ore, molecules can exchan(e their position. This is calledtransition movement. The molecules can also interchan(e bet+een t+o la ers this is called Aip4Aopmovement. The 2roteins are o t+o t pes!eripheral protein &e'trinsic protein(" The are present either inner or outer sur ace.)ntrinsic protein" It is partiall or completel embedded in phospholipids.#unction of cell membraneIt is the outer coverin( membrane o animal cell, +hich maintain cell shape, helps in di*usion, helpsin osmosis endoc tosis 8intake o lar(e molecules in to the cell9 and exoc tosis /xpellin( o lar(emolecules o li uid or solid rom the cell.

!rotoplasmIt is ound inside cell membrane. It is a li uid mass viscous in nature. It contains several livin( andnon4livin( thin(s. It is divided into t+o parts

Cytoplasm" It is li uid mass present bet+een plasma membrane and nuclear membrane. it isdi*erentiated into t+o la ers The outer ectoplasm +hich is non (ranular and inner endoplasm +hich is(ranular containin( cell inclusions and cell or(anelles.*ucleolasm" It is li uid material +ithin nuclear membrane.

ell Organelles

The are livin( sub cellular structures +hich are embedded +ithin c toplasm.a( itochondria & itochondrion(

Its shape is variable and the si e ran(e rom @46 micrometer. It is double membrane structure. Itsouter membrane is smooth and re(ular. Its inner membrane (ives fn(er like pro ections to+ardsinner side called cristae . The sur ace o the cristae contains number o stalked and (lobular proteinscalled oxysomes . The cavit bounded b membrane is flled +ith a li uid mass called matrix . Thmatrix contains


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The main unction o the leucoplast is to store ood materials. It is present in the stem and root. The leucoplast+hich store starch is called amyloplast , +hich stores oil, is called elaioplast and +hich stores protein calledaleuroplast .

c( %ndoplasmic .eticulumIt is the net+ork o tube like structures and sac like structures. It arises rom nuclear membrane andextends up to cell membrane. The endoplasmic reticulum is ormed b three structures.Cisternae" The are lon( elon(ated Aattened unbranched sac like structures lie parallel to each

other./esicles" The are minute spherical or oval sac like structuresTubules" The are branched tube like structures the orm net +ork +ith cisternae and vesicles.

#unction of %.It provides mechanical support to the cell. There ore, it is also kno+n as c toskeleton. It s nthesi esproteins and hormones. It helps to transport ions, molecules and impulse or metabolites. It ormsnuclear membrane. It also orms ne+ cell membrane and components.

There are two types of %.

d( 0olgi bodyIt is also kno+n as lipochondria or dict osomeIt arises rom /R and is ormed b our structures. It lies near cell membraneCisternae" The are curved +ith dilated ends and are parallel to each other/esicles" The lie on convex side o cisternae/acuoles" The are lar(er sac like structures lie on concave side o cisternae.Tubules" The ormed net +ith cisternae vesicles and vacuoles#unctions of 0olgi bodyIt orms ne+ cell membrane, It orms cell +all components, It secrets hormones, It stores proteins and

ats.It orms vesicles and l sosomese( .ibosome

The are small dense (ranular particles o R;) and proteins. It is also kno+n as ribonucleioproteins. The are ound reel in c toplasm and ound on the sur ace o endoplasmic reticulum and +ithinsome cell or(anelles. It is not bounded b an membrane. /ach particle o ribosome consists o t+osubunits i.e. Bne lar(er and another smaller cap like subunit over lar(er subunit. There are t+o t peso ribosome

#unction of .ibosomeIt is the site o protein s nthesis, it also stores protein, and there ore ribosome is called protein=actor .

f( -ysosomes

.ough %. Smooth %.It bears ribosomes on its sur aceIt is ound near nuclear membrane

It is ormed b nuclear membraneIn it mainl cisternae are ound

It bears no ribosomesIt is ound near cell membrane

It is ormed b rou(h /RIn it mainl tubules are ound

12S type 32 S type

It is smaller in si e and the number o protein is55

The ratio o R;) and protein is @ 17olecular +ei(ht is @.>D10 6


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The l sosomes are vesicles like structures bounded b sin(le membrane the l sosome containsseveral en mes that di(est extra cellular and intra cellular substances. - sosomes di(est cellor(anelles causin( death o cell. There ore, it is called suicidal ba(. There are our t pes o l sosomes!rimary lysosomes"

The ne+l ormed l sosomes containin( inactive en mes are called primar l sosomes.Secondary lysosomes

These are ormed b usion o primar l sosomes +ith active en mes, +hich di(est unnecessarparticles.Tertiary lysosomes "- sosome containin( undi(ested ood is called tertiar l sosome or residual bod .4utolysosome" - sosome +hich di(ests cell or(anelles is called auto l sosome.#unction of -ysosomeIt di(ests dead cells, it di(ests extra and intra cellular particles, it in(est particles

g( Centrosome The centrosome is (lobose bod , +hich consists o t+o star shaped structures called centrioles . /achcentriole consists o nine ro+s o triplet fbrils and remains surrounded b c toplasmic area calledcentrosphere . Ehen centrosome is present at the base o Aa(ella or cilia then it is called basal body . #unction of Centro some


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ell DivisionIt is a c clic process in +hich the division o nucleus is ollo+ed b division o c toplasm as a resultdau(hter cells are ormed.

Cell Cycle)ll the chan(es that take place durin( cell (ro+th and cell division are called cell c cle. !ell c cle can be divided intoollo+in( phases)nterphase" The sta(e +hen cell becomes read to divide is called interphase. It is subdivided into $1 2hase, $@

2hase, 2hase9aryo$inesis" It is the process o division o nucleus. It is subdivided into 2rophase, 7etaphase, )naphase,

Telophase.Cyto$inesis It is the process o division o c toplasm.

TYPES OF ELL DIVISION:, 4mitosis cell di6ision or direct cell di6ision

This cell division takes place in prokar otic and unicellular eukar otic animals.


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• !hromosomes at each pole become elon(ated lon( coiled ormin( chromatin net+ork• ;uclear membrane and nucleolus reappears• Thus, t+o nuclei are ormed at each pole.

Cytokinesis The process o division o c toplasm is called c tokinesis

a, Cell plate ethod• ;umber o vacuoles and vesicles used to(ether at the middle o cell bet+een t+o nuclei ormin( a plate like

structures. The plate like structures are called phra(moplast• !ell +all components accumulates at the each side o the cell plate• )nd sin(le cell is divided into t+o dau(hter cells• This method takes place in plant cell.

b, Clea6age ethod• ;o cell plate is ormed in this method.• The c toplasm is constricted directl rom the constriction o cell membrane and

ultimatel the cell is divided into t+o parts.• This method takes place in animal cell.

Signi5cance of itosis• It keeps the chromosome number constant and (enetic stabilit in dau(hter cells, so the linear heredit o an

or(anism is maintained.• It helps in (ro+th and development o (ote into adult.• It pla s a si(nifcant role in +ound healin(, replacement o old and deca in( and dead cells and re(eneration

o lost parts.• It helps the cell in maintainin( proper si e• It also helps in asexual reproduction b ra(mentation, buddin(, stem cuttin( etc.

• Throu(h the process, e uilibrium is maintained in the amount o


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Diplotene• :ncoilin( o chromosomes takes place rom centromere due to a kind o repulsive orce• ome parts ho+ever remain still attached at certain points• The attachin( points are called chaismata.• )t chiasmata chromosomal se(ments are broken and re oined cross +ise i.e. /xchan(e o maternal and

paternal chromosomal se(ments.• This phenomenon is called crossin( over• ome auther mention the crossin( over takes place in pach tene sta(e.

Dia$inesis• !hiasmata move to+ards the end o chromosome. This process is called terminali ation• The nuclear membrane starts to disappear• ;ucleolus also disappear

etaphase )• pindle fbers appears• !hromosomes arran(e at the e uator centromere o each bivalent ace to+ards opposite

pole.• Bne centromere o each bivalent becomes attached +ith spindle fbers o one pole and

another centromere o each bivalent (ets attached +ith spindle fbers o another pole.

4naphase )• /ach bivalent separate to(ether• eparated bivalent move to+ards opposite poles due to contraction o spindle fber• T+o (roups o chromosomes are ormed at each pole havin( haploid number o

chromosomes

Telophase )• !hromosomes arran(e into t+o (roups one at each pole• ;uclear membrane and nucleolus reappears•

pindle fbers disappear• !hromosomes become lon( elon(ated to orm chromatin

Cyto$inesis" It ma or ma not occurs

eiosis ))It is called e uational division or homot pical division because the cells produced a ter meiosis Iunder(o urther division to produce our cells +here chromosome number remains same as that o parent cells, similar to mitosis.

Karyo inesis!rophase ))

The !hromosome become shorter and thicker, ;uclear membrane and nucleolusdisappear. pindle fbers start to appear

etaphase ))• !hromosomes arran(ed at the e uator• The centromere o each chromosome divides into t+o centromeres in lon(itudinal +a .• Bne centromere o each chromosome is connected +ith spindle fber o one pole and

another centromere is connected +ith spindle fber o another pole.

4naphase ))


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• ) kind o repulsive orce is developed bet+een t+o dau(hter centromeres• Bne o the t+o centromeres havin( its o+n chromatids move to+ards one pole and

another centromere move to+ards another pole• T+o (roups o chromosomes are ormed at each pole due to contraction o spindle fbers.

Telophase ))• !hromosomes or(ani e into nucleus at each pole•

!hromosomes become lon(, elon(ated ormin( chromatin• ;uclear membrane and nucleolus reappears• pindle fbers disappears

Cyto$inesisSuccessi6e method

The frst c tokinesis takes place a ter meiosis frst to orm t+o dau(hter cells andsecond c tokinesis takes place a ter meiosis II to orm our dau(hter cells. Theprocess is called successive 7ethod.Simultaneous ethodIn this method, c tokinesis takes place onl a ter 7eiosis II to produce our dau(htercells.

Signi5cance of eiosis cell di6ision• $ametes and spores are ormed b meiosis divisions that are essential or sexual reproduction• 7eiosis helps to maintain fx number o chromosomes in or(anisms• !rossin( over causes the (enetic variation amon( the species• It helps in alternation o (enerations o haploid and diploid (enerations o plants and animals• The se(re(ation o paired chromosome resultin( in di*erent combination o character dau(hter

cells.


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It occurs in somatic cells7itosis division completed onl in one division!rophaseIt is ver short

napses is absent;o coilin( and no replication takes place

;o chiasmata ormation takes place;o crossin( over takes place;o Kariation occurs

etaphaseBne metaphasic plate is ormed!ontromere divides lon(itudinall4naphase

T+o chromatids o each chromosome separateand move to+ards opposite pole/ach chromosome is sin(le stranded

Telophase;ucleus id diploid

T+o nuclei are ormed T+o cells are produced a ter c tokinesis

It occurs in reproductive cells7eiosis division is completed in t+o successivedivisions!rophase2rophase is ver lon( ubdivided into 5 sub phasesIn ' (otene s napses occursIn 2ahc tene homolo(ous chromosome under(ocoilin( and replication occursIn diplotene chiasmata ormation and crossin( overtakes placeKariation occurs

etaphase T+o metaphase plate is ormed!entromere does not divide in 7eiosis I but in II4naphaseHomolo(ous chromosomes separate and moveto+ards opposite pole/ach chromosome is double stranded n meiosis ITelophase;uclei are haploid=our nuclei are ormed a ter Telophase II=our cells are produced a ter c tokinesis II

TA!ONO"Y The taxonom is the branch o biolo( , +hich deals +ith identifcation, namin(, and classifcation o or(anisms. The ather o taxonom is considered as Carolus -innaeus,

>inomial *omenclature The s stem o (ivin( scientifc name to or(anisms b usin( t+o -atin +ords is called binomialnomenclature. =or example "ana tigrina 8=ro(9. The frst +ord represents (enus and the name is called(eneric name. The second +ord represents species and called specifc name. ome o the scientifcnames o or(anisms are (iven belo+.

7an #omo sapiens -ion Panthera tigrisBnion Allium sepa $arlic Allium sativum2otato $olanum tuberosum Rat "attus rattus

.ules of binomial nomenclature• cientifc name should be in t+o -atin +ords.• The scientifc name should be italici ed.• cientifc name should be underlined in hand +ritten script• The (eneric name should be started rom capital letter and the specifc name should be started

rom small letter.• The scientifc name o the t+o or more or(anisms should not be similar.

Two 9ingdom System of Classi5cationCarolus -innaeus divided the or(anisms into t+o kin(doms, the plant Lin(dom and the )nimalLin(dom. This s stem +as based on the characteristics o animals and the plants.


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)n cate(or o the taxonomic (roup o an rank is called taxon *pleural+taxa

Ta'onomic 7igherarchy The arran(ement o taxonomic cate(ories based on the taxonomic rank is called taxonomic higherarchy The hi(hest rank o the taxonomic cate(ories is kin(dom and the lo+est rank is species.

What is species or why species is called basic unit of ta'onomy? The species means (roup o individuals havin( ver close relationship and the can reproducesuccess ull . %elo+ species, there is no an rank o taxonomic cate(or . There ore, it is called basic unito taxonom , or e(. tigrina is the species o ro(.0enus" The (roup o t+o or more species havin( similarit in man characters is called (enus, or e(.

"ana is the (enus o ro(.#amily" The (roup o t+o or more (enus havin( similarit in man characters is called amil , or e(

Ranidae is the amil o ro(.Order" The (roup o t+o or more amil havin( similarit in man characters is called order, or e( )nura

is the amil o ro(.Di6ision" The (roup o t+o or more orders havin( similarit in man characters is called division, or e(

$nathostomata is the amil o ro(.Class" The (roup o t+o or more divisions havin( similarit in man characters is called class, or e(

)mphibia is the amil o ro(.!hylum" The (roup o t+o or more classes havin( similarit in man characters is called 2h lum, or e(

!hordata is the amil o ro(.9ingdom" The (roup o t+o or more ph la havin( similarit in man characters is called kin(dom, or e(

)nimalia is the amil o ro(.

KINGDO" "ONERA>4CT%.)4

%acteria are discovered b )nton Kan -eeu+enhoek in 16>6. The are ound ever +here in air, +ater,soil, and bodies o or(anisms. There is no natural death o bacteria. The are killed either usin(chemicals or b in ectin( +ith virus.

orphologyi e o the bacteria varies rom @453m and 0.#40."3m +idth in rod shaped bacteria. In spherical bacteria

the si e varies rom 0.5 N 13m in diameter.Spherical bacteria" the bacteria havin( spherical in shape are called coccus bacteria . The coccusbacteria ma be ound sin(l and reel are called monococcus or micrococcus. Ehen the are ound inthe (roup o t+o is called diploccus. ometimes the are ound in the (roup o our are calledtetracoccus. ome o them are ound in chain are called streptococcus and some are ound in lar(e (rouplike bunch o (rape called staph lococcus..od li$e >acteria " the bacteria havin( shape o the cell is i rod like called bacillus. The bacillus bacteriaare ound in sin(l and reel are called monobacillus. ome o them are ound in the (roup o t+o arecalled diplobacillus. The are also ound in chain are called streptobacillus.

7elical >acteria" The bacteria havin( shape o the cell is coiled called helical bacteria. These are o t+ot pes

/ibrio" The bacteria havin( the shape are comma like are called Kibrio. e(. 'ibrio cholera .Spirillum" The bacteria havin( shape is helicall coiled are called pirillum.

Cell StructureCapsule


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The capsule is the outer most coverin( o (elatinous substance is called capsule. It is made up o pol saccharides. The capsule ma be absent in some bacteria. The are called non4capsulated bacteria and other havin( capsule are called capsulatedbacteria. :suall the capsulated bacteria are poisonous or virulentthat causes diseases and the non4capsulated bacteria are non4virulent.

The unction o the capsule is to protect cell, protects romdesiccation and secrets poisons.Cell wallIt is ound under the capsule in capsulated bacteria and theoutermost la er in non4capsulated bacteria. It is ri(id and iscomposed o a kind o complex substance called peptidoglycan or )urine or )ucopeptide.

The peptido(l can is composed o complex carboh drates called ;4acet le muramic acid and ; acet l (lucosamine and aminoacid ie. -alanine, < alsnine and < (lutanic acid.2ol saccharides and lipids are also present in cell +all.

Bn the basis o cell +all structure and stain retainin( propertbacteria are t+o t pes

$ram positive $ram ;e(ative %acteria

In (ram positive bacteria cell +all is thick8@54#0nm9

The peptido(l can amount is @04"0O There is no lipopol sacharide in cell +all-ipid is about 04@O

The retain violet or blue colour in $ramMsstain

The cell +all is thin about 10415nm

2eptido(l can is 104@0O-ipopol saccharide la er is present-ipid is about 104@0O

The retain pink or red color in $ramMs stain

#unction of cell wallIt provides ri(idit to the cell, it maintains cell shape it protects protoplasm o the cell.

Cell membraneIt is thin elastic and permeable membrane made up o protein and phospholipids. The main unction isprotection, maintains cell shape, and helps in osmosis and di*usion.

.eproduction%acteria usuall reproduce b ase'ual method,

>inary 5ssion The nuclear material becomes enlar(ed and divides into t+oparts. !onstriction is made in the middle o the cell on the cellmembrane dividin( c toplasm into t+o parts. :ltimatel , a cellis divided into t+o dau(hter cells. This method is vercommon and simplest method o reproduction in bacteria. %this method, about @500,000 bacterial cells are produced in anhour.

>udding


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that end b constriction o cell membrane. ) spore is then ormed at that end. It releases out in the soiland ma remain viable or several ears. :nder avorable condition, it (erminates to produce ne+bacterial cells.Se'ual reproduction

The recombination o (enes o bacterial cells throu(h di*erent +a s rom one to another cell is considered as thesexual reproduction. This is o ollo+in( t pesTransformation

The process o entrance o exo(enous


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C 4*O>4CT%.)40eneral Characters

• 7ostl c aobacteria are a uatic and some are terrestrial.• The or(anisms are prokar otic. The ma be unicellular, colonial.• !ell +all is composed o cellulose.• =la(ella are absent. 7esosomes are absent like bacteria.• The contain photos nthetic pi(ments, so the are autotrophs.• ;o sex or(ans are produced and sexual reproduction is absent.• The reproduce asexuall .

Bne o the important members o c anobacteria is ostoc

Nostoc The are ound in resh +ater, padd feld. The bod is flamentous +hich is simple,unbranched, and covered b (elatinous sheath. =ilament +ithout (elatinous sheathis called trichome . Trichome is made up o small spherical or oval cells.)t re uent interval there are some speciali ed lar(e elon(ated and thick +alledcells called heteroc st. The heteroc st consists o t+o polar nodules. Theheteroc st helps to fx atmospheric nitro(en. Heteroc st is intercalar 8in bet+eent+o ve(etative cells9 but sometimes it is terminal 8at the end o the flament9

.eproduction

Nostoc does not develop sex or(ans. It reproduces b asexual method.#ragmentation" +hen the colon breaks into small piece or ra(ment ne+ colon isormed rom each ra(ment.

7ormogonia" The flament breaks into point o heteroc sts. /ach piece is called horomo(onia and orm that ne+colon is ormed.7eterocysts" The heteroc st itsel (erminates and produces ne+ flament.4$inetes" :nder avorable condition somatic cells store ood materials, +hich become thick +alled called akinetes.

The (erminate to orm ne+ flament and colon .

%conomic importance of Cyanobacteria• ! anobacteria are the source o ood or a uatic animals.• The also fx atmospheric nitro(en in crop (ro+in( feld.• The are nutritious and decrease the alkalinit o the soil.• ome species are toxic to a uatic animals cause poison.• )ccumulation o c anobacteria in +ater source contaminates and pollutes +ater.

KINGDO" # PLANTAE The or(anisms are autotrophic, %od is hi(hl branched, and reserved ood is starch This kin(dom is divided into # (roups4lgae

!hloroph ceae 8$reen )l(ae92haeoph ceae 8%ro+n )l(ae9Rhodoph ceae 8Red )l(ae9

>ryophyta &4mphibious !lants(

-iver+orts7oss

Trachophyta2teridoph ta 8Kascular !r pto(ames9$ mnosperms 8;aked eeded 2lants9)n(iosperms 8!losed eeded 2lants9


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4lgaeChlorophyceae !haeophyceae .hodophyceae

• The are kno+n as (reenal(ae

• The comprise about>000 species

• The are mostl ound inresh +ater

• The contain chloroph llsa,b

• !ell +all is made up o outer pectose and inner cellulose

• The are both unicellularand muclticellular

• Reserved ood is stored inthe orm o starch.

• )sexual reproduction

takes place b the ormation omotile spores like oospores andaplanospores

• exual reproduction isiso(amous, aniso(amous andoo(amous

=or e(. $pirogyra.

The are kno+n as bro+n al(ae

The comprise @000 species

The are mostl ound in marine +ater The contain carotene and ucoxanthin asphotos nthetic pi(ents!ell +all is made up o outer al(inic acidand inner cellulose

The are onl multicellular

Reserved ood is mannitol andlamminarin.)sexual reproduction takes place b the

ormation o oospores

exual reproduction is iso(amous or

aniso (amous and oo(amous=or e( 9ucus

The are kno+n as red al(ae

The comprise about 5000 species The are both a uatic and marine The contain ph coer thrin andph coc anin as photos ntheticpi(ments!ell +all is made up o outer pectinand inner cellulose

The are unicellular and multicellularReserved ood is stored in the orm o Aoridean starch.)sexual reproduction takes place bthe ormation o nonmotile sporeslike monospores

exual reproduction is onloo(amous t pe

=or e( %atrachospermum

Spirogyra7abitat

The are abundantl ound in resh +ater resources like ponds pools, ditches, sprin(s, lakes, streams etc. the are+idel distributed throu(hout the +orld.


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Structure The plant bod is thalloid. The thallus is unbranched or unattached. The thallus is called flament. The oun(flament is attached to some substratum b the help o basal cells. /ach flament consists o man c lindrical cells.

The cells are lon(er than breadth. The cell is surrounded b (elatinous sheath. !ell +all is outermost la er, +hich isri(id and consists o t+o la ers. The outer la er is made up o pectose and inner la er is made up o cellulose. T+ocells in the flament are separated b a common +all, +hich is called septum. The c toplasm contains cell inclusionsand cell or(anelles. There is a central vacuole in the centre o +ell +hich is surrounded b a la er called tonoplast.

The vacuole is flled b a li uid called cell sap. There is a nucleus at the centre o vacuole. In each cell, spirall coiledchloroplast is present in the c toplasm. In chloroplast, round and spherical bodies are ound +hich are called

pyrinoid .

.eproduction4se'ual reproduction#ragmentationIt is common method o ve(etative reproduction. In this method, the flament ma breaks up into small

ra(ments and each such ra(ment (ro+s into ne+ flament.

4$inetes:nder un avorable condition, some cells o the flament become thick +alled +hich are called akinetes

The akinetes (erminate to produce ne+ flaments.4planospores

The aplanospores are thin +alled spores, +hich arise sin(l in the flament. The protoplast o the cell

loses +ater and contracts. It rounds o* and secrets thin +all around it to become an aplanospore. It(erminates to produce ne+ flament.

Se'ual reproductionexual reproduction takes place b con u(ation method. Ehen cells o t+o flaments con u(ate then it is

called as con u(ation. There are three methods o con u(ation

a( Scalariform conjugation• In this method, t+o flaments o spiro( ra come close and lie parallel to each other in opposite

direction.• T+o flaments (et surrounded b common mucila(e sheath.• The cells o the flaments produce small out(ro+ths to+ards each other, +hich are called papillae.• The papillae o opposite flament (et enlar(ed and use to(ether.• The common +all o papillae (ets dissolve ormin( tube like structures, +hich is called

con u(ation tube. )t this sta(e, it appears ladder like structure, +hich is called scalariform .

• The protoplast o con u(atin( cells contract b losin( +ater ormin( (ametes. The (amete bearin(cells are called gametangia .

• The (ametes o one flament move to+ards the cells o another flament throu(h con u(ationtube.

• The mi(rator (ametes are male (ametes and stationar (ametes are emale (ametes.• T+o (ametes use to(ether to rom (ote in one flament to orm (ote and the (ote secretes

+all around it, +hich is called as (ospore, but the cells o another flament, remain empt .

b( -ateral conjugation• The con u(ation takes place bet+een ad acent cells o the same flament is called lateral

con u(ation There are t+o t pes o lateral con u(ation

Direct lateral conjugation• In this method, the protoplast o ad acent cells contracts b loosin(

+ater and rom (ametes.• In the upper protoplast a conical tube like structure is ormed +hich

is called male (amete. The lo+er protoplast is no+ called emale (amete. ;o+male (amete penetrates common septum, move do+n+ards and uses +ith

emale to rom (ote and then (ospore.)ndirect lateral conjugation


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• T+o ad acent cells develop small out(ro+th on either sidei.e. near septum, +hich is called papillae.

• The common +all bet+een t+o papillae (ets dissolved andcon u(ation tube is ormed bet+een t+o ad acent cells.

• The protoplast o t+o ad acent cells becomes contract,+hich is called (ametes. The upper cell is called male(amete and start to move to lo+er cell throu(h con u(ationtube.

•

;o+, male and lo+er emale (amete use to(ether to orm(ote and the (ote secrets +all around it to orm(ospore.

=ygospore germination The flament o the (ospores deca and (ospore becomes thick +alled. The thick +alled (ospore

sinks at the bottom o +ater. Thediploid nucleus o (osporeunder(oes meiosis divisionand produces our nuclei.But o our nuclei threede(enerate and oneremains unctional. ;o+ the

outer +all o (ospore ruptures

and inner +all produce small tube called (erm tube.;o+ the (erm tube divides transversel +ith nucleus and septa are ormed +ith the ormation one ne+flament.

Bryo$%y&a The include &60 (enera and @ 000 species. The (ro+ in moist and shad places and some are a uatic.2lant bod does not bear vascular tissues and not di*erentiated into root shoot and leaves. The sho+alternation o (eneration that is in the li e c cle t+o orms o the plant bod are produced.0ametophytic generation• The plant bod in this (eneration produces (ametes or sexual reproduction.• The (ametoph tic (eneration is lon( lived.• The plant bod is (reen autotrophic consists o root like structures on the ventral sur ace called rhi oids and

scales• The plant bod bears male and emale sex or(ans +here male and emale (ametes are produced.• The male sex or(ans are called antheridia and the emale sex or(ans are called arche(onia.• Eater is essential or ertili ation.• ;o embr o is developed rom the development o (ote.Sporophytic generation• Ehen male and emale (ametes use to(ether (ote is ormed +hich develops into sporoph tic

plant bod .• This (eneration is short lived.• The sporoph tic plant bod is di*erentiated into oot seta and capsule.• Eithin capsule o saproph te spores are produced b meiosis division in spore mother cells. /(.

)archantia, 9unaria


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MarchantiaIt is one o the important species o -iver+orts. It is +idel distributed, commonl ound in moist and shad places.

There are about 65 species o marchantia. In ;epal there are three species ound )archantia palmate, ).nepalensis, ). polymorpha.

0ametophyte

%'ternal Structure• The plant bod is thalloid. The thallus is dorsoventrall Aattened, prostrate,

and dichotomousl branched.• Bn the dorsal sur ace there is dark (reen colored mid rib.• The mid rib bears (amma cup or asexual reproduction• The ventral sur ace consists o unicellular, tubular, colorless structures called rhi oids

and multicellular plate like violet in colour structures are present called scales.• The rhi oids absorb +ater. The are o t+o t pes

o mooth rhi oids +hich are thin +alled.o Tuberculate rhi oids +hich are thick +alled

• The scales protect rom the in uries to the thallus and transport +ater. Thescales are simple and complex.

• )t the apex o the thallus there is apical notch.• The male and emale plants are ound separatel i.e. dioecuious.• In male plant male sex or(ans, )ntheridia are produced and in =emale plant

emale sex or(ans, arche(onia are produced.)nternal structure• Bn the dorsal and ventral sur ace o the thallus outermost sin(le la ered

epidermis is present.• The upper epidermis consists o air pores• The air chambers are present belo+ upper epidermis.• The air chambers are separated b partition +alls.• In air chamber there are photos nthetic flaments +hich are made up o cells +hich are rich in chloroplast

+here ood is s nthesi ed. It is s nthesi in( one.• %elo+ s nthesi in( one, there is a re(ion o compactl arran(ed paranch matous cells, +hich are thin,

+alled that store ood. It is stora(e one.• -o+er epidermis consists o number o rhi oids and scales.

.eproduction>y fragmentationIn this older re(ion o thallus deca ed or de(enerate and oun(er re(ion or apical re(ion a(ain re(enerate andproduce ne+ plant bod .>y ad6entitious branchesIn this method, branches develop on the ventral sur ace o thallus. ;o+ branch (ro+s into ne+ plantbod .>y gemmae

The cup like structures is ound on the midrib o dorsal sur ace. Eithin (emma cup small stalked structures areormed called (ammae. The (ammae are asexual reproductive structures, +hich are made up o parench matous

cells. Bn the lateral side o (emmae notch is present. The cells o the (ammae are flled +ith chloroplast. Ehen the(emmae all on the (round, the produce ne+ plant bod .

Sexual Reproduction The )archantia is dioecious or heterothallic i.e. male and emale sex or(ans are ound in separate individual. Themale sex or(an is ound in male plant and emale sex or(ans are ound in emale plant. The sexual reproductiontakes place b usion o male and emale (amete.

ale gametophyte• The male (ametes are called anthero oids. /ach anthero oid is

elon(ated, coiled, and Aa(ellated. )nhtero oids are ormed +ithin male sexor(an called antheridium. /ach antheridium is (lobular +ith short stalked and

acket la er encloses numerous cells called androc tes.• /ach androc tes orms anthero oids +hen antheridium (ets ruptured

and thero oids liberate out. The antheridia are ond on the upper sur ace o thereceptacle o antheridiophore.


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• /ach anterridium is embedded in a cavit . The cavit opens outside throu(h a pore called ostiole. Theanthero oids come out throu(h ostiole and s+im in +ater.

#emale gametophyte• The emale plant bears arche(oniophore. It is 54> cm lon(. It consists o stalked and star like emale

receptacle. :suall receptacle has nine ra s o star like structure.• ;umerous emale sex or(ans called arche(onia are han(in( in lo+er part o emale receptacle.• )rche(onia consists s+ollen basal portion called Kenter and elon(ated neck.• The Kenter consists o a prominent cell called e((. ;ear e((, there is another cell and Kenter canal cell. !ell

in the neck are called neck canal cell.

#ertilization+immin( anthero oid reach to the arche(onia tip +ith the help o +ater. ;eck canal cell o arche(onia (ets

dissolved. ) kind o mucila(e is secreted b dissolvin( neck canal cells and reaches to the venter canal cell and (etsused +ith e(( and (ote is ormed.

Sporophyte• The (ote under(oes number o cell division durin( development and the structure

o (ote at that sta(e is called sporoph te.• The basal portion o the sporoph te is called oot and middle elon(ated portion is

called seta.• Round (lobular terminal part is called capsule +hich consists o thread like elaters

and number o unicellular spores ormed b meiosis division in spore mother cells

+ithin capsule.• The capsule is surrounded b a la er called acket.• The +hole sporoph te is surrounded b la er o cell called cal ptra. /laters help in

spore dischar(e +hen acket or capsule is ruptured.• The sporoph te is parasitic because it depends up on emale (ametoph te.• Hal o the spores (erminate produce male (ametoph te and hal (erminate to

produce emale (ametoph te.

FunariaIt is cosmopolitan in distribution, mostl ound in moist soil, rock, +alls, and tree trunks.

0ametophyte%'ternal structures

2lant is small about 14# cm lon(, stem is erect and branched. It is di*erentiated intorhi oids, axis, and leaves. The rhi oids are multicellular and branched. The axis isaerial, erect, and branched. The leaves are simple, small, and spirall arran(ed. Theupper leaves are lar(e and lo+er leaves are cro+ded.

)ntenal structureStem" The outermost la er is epidermis contain chloroplast. %elo+ the epidermis there

is multilaered parench ma called cortex. In the centre there is compact and narro+cells +ithout protoplast called central c linder +hich actions as conductin( tissue.-ea6es" The lea lamina consists o sin(le la ered parench ma rich in chloroplast andthe midrib contains central strand.

.eproduction)sexual method o reproduction takes place b ollo+in( method>y primary protonema" The spores (erminate to (ive rise small flament called primar protonems, +hichcontains small buds rom +here ne+ plant is produced.


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>y secondary protonema" The flament can (ro+ rom stem, leaves, or rhi oids called secondar 2rotonems. The bear small buds and +hich are capable to (ive rise ne+ plant.>y gemmae" The small multicellular structures develop on leaves and axis, +hich develop into ne+ plant.>y bulbil" The (ammae like structures developed on the rhi oids are called bulbils +hich (ro+ into ne+ plant.

Se'ual reproduction=unaria is monoecious emale or(ans develop or separate branch o same plant autocious.

ale branch @ the branch +ith male sex or(ans id called male branch.•

The male sex or(ans 4 )ntheridia develop in (roup at the apex o shoot• The are mixed +ith hair like structure paraph sis.• )ntheridia and paraph sis are surrounded b leaves called perichaetial leaves.

/ach antneridiuim is stalked, club4shaped, surrounded b acket t+o apex cells are lar(ePthick calledoperculum. Eith the help o +ater, the operculum ruptures and androc tes come out and chan(einto anthero oids 8spermato oids9.

#emale branch A The branch +ith emale sex or(ans.• The emale sex or(an N )rche(onia are developed at the apex o shoot.• The arche(onia are mixed +ith hair like sterile structures called paraph sis.• %oth surrounded b perichaetial leaves./ach arche(onium is Aask shaped, stalked, and contains broad Kenter and lon( neck. The Kentercontains an e((, Kenter canal cell, double la ered +all. ;eck contains neck canal cells.#ertilizationIn pressure o +ater anthero oid reach to arche(onia tip. ;eck canalPKenter canal cells de(enerate.

anthero oids enter throu(h neck and onl one ree +ith e(( to orm (ote.

SporophyteThe (ote secrets thick +all around it called oospore, +hich (ro+s into a saproph te. The maturesaproph te consists o ootQsetaQcapsule

• =oot N it is barrel, conical shaped, embedded in apex o a branch.• eta N it is ver lon(, t+isted, and slender.• !apsule4 pear shaped in structure and it consists o

o )poph sis N it is multicellular thick basal portion o the capsuleo !olumella4 it is central portion o the capsule surrounded b spore sac.o pore sac4 it is a sac containin( spores on either side o columella. Bn the outer side o the spore sac

air spaces are present separated b partition +all.o Bperculum N apical re(ion o capsule. It is conical lid o the capsule. It consists o small

teeth called peristome .Dehiscence of capsule)t maturit annulus breaks and the operculum is thro+n a+a . The spores are liberated out.Spore germination:nder avorable condition the spore, (erminate to produce small flament. The flament branches reelcalled primar protonema. The primar protonema (ives small buds. /ach bud (ives rise into ne+9unaria plant.

%ametop!&te

%emmae

'ulbil

("ima"& p"otonema)econda"& p"otonema

*ale b"anc! +emale b"anc!

Ant!e"idia A"c!e,onia

Ant!e"o-oids ./um 0e,,

&,ote apsule)po"op!&te

)po"e )ac

)po"es

("ima"& p"otonema


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!teridophyta The are trul land plants that (ro+ +ell in moist shad cool places. The plant bod is sporoph te, +hichis di*erentiated into lea stem and roots. The sporoph te is the dominant sta(e in the li e c cle. Ehich iscompletel independent attheadult sta(e The are +ell4developed vascular plants there ore the arealso called vascular cr pto(ams. The spores on (ermination (ive rise to (ametoph tic phase, +hich isshort lived. The (ametoph tic phase is autotrophic and independent. The +ater is essential or

ertili ation. )lternation o (eneration takes place.#ern (Dryopteris)

7abitat!ommonl ound in moist and shad places in tropical to temperate re(ion. ome are ond in a uatichabitat as epiph te i.e. (ro+in( on trunk o trees.

Sporophyte%'ternal structure

• The plant bod is sporoph tic and di*erentiated into root, stem, and lea . The root isfbrous and arises rom stem. The roots are short lived and there ore called ephemeraland branched.

• The stem is under(round hori ontall placed, branched or unbranched. Its colour isdark bro+n. It is called rhi ome. It is covered b bro+n hairs called remanta +hichprotects oun( leaves rom the in ur and dr in(.

• The lea is aerial part. It consists o thick and stout petiole. Bn the either side o rachis,pinnae are present. The oun( leaves are curved and called circinate leaves.

)nternal structure.oot• Transverse section o root sho+s that the outermost la er o root is epidermis. In oun( root hairs

are present. %elo+ epidermis, there is multila ered broad re(ion o cortex, +hich is di*erentiated intot+o re(ions.

• Buter cortex is made up o thin +alled parench ma, +hich stores ood, and transport +ater.• Inner cortex is made up o thick +alled sclerench ma, +hich (ives mechanical stren(th to the

root.


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• %elo+ inner cortex, there is sin(le la er o barrel shaped cells called endodermis containin(chloroplasts. It stores and orms starch.

• /ndodermis is ollo+ed b peric cle, +hich is composed o compactl arran(ed one, or t+o la erso thin +alled cells. There is a vascular c linder surrounded b peric cle. It has x lem and phloem.

There are t+o lar(e si ed metax lems and on either side o metax lem small protox lems lie at t+osides. %oth x lems are surrounded b phloem.

Stem• The outer most la ers are sin(le la ered called epidermis. The epidermis is covered out+ardl b

a la er o non4livin( materials called cuticle. %elo+ epidermis, there is multila ered broad re(ion o cortex, +hich is di*erentiated into t+o re(ions.

• Buter cortex is made up o thick +alled sclerench matous cell, +hich is called h podermis. It(ives mechanical support to the plant.

• Inner cortex is made up o thin +alled parench matous +hich stores ood.• %elo+ cortex vascular bundle is s dict ostele, +hich consists o a hollo+ and c lindrical man

vascular bundles called meristeles. /ach meristele has its o+n endodermis, peric cle, phloem, andx lem.

• The re(ion bet+een the meristele is called pith.• /ndodermis is the outer most la ers made up o barrel shaped cells. %elo+ it la er o thin +alled

parench matous cells present called peric cle.• The x lem and phloem are surrounded b peric cle and either side o metax lem protox lem lies.

The phloem surrounds the both x lems.!etiole• The outer la er is sin(le la er cell called epidermis. It is surrouded b a la er o cuticle. %elo+ epidermis,

there is a e+ la er o thick +alled sclerench matous cell called h podermis. The h podermis is ollo+ed b thin+alled parench ma, +hich is called inner cortex.

• The vascular bundle is dissected into number o vascular c linders so called dict ostele. /ach vascularc linder is called meristele havin( o+n endodermis, peric cle, x lem and phloem. The re(ion bet+een themeristele is called pith.

.eproduction• The ern plant is sporoph tic that produces spores. The spores are unicellular uninucleated

thick +alled and dust appearance. The spores are produced +ithin sporan(ia. /achsporan(ium has a short stalk and capsule covered b sin(le la er o cells called acket.

• The capsule has some Aat cells called annulus and a demarcation or break called stomium. The spores are ormed +ithin capsule. In dr condition annulus contract, loosin( +ater andsporan(ium or capsule ruptured throu(h stomium and spores are released out.

• poran(ia are ound in a (roup. The (roup is called sorus. ori are ound on the ventralsur ace o pinnae. 2innae, +hich bear sori, are called sporoph lls.

• The sori usuall dark bro+n in colour and are round patches arran(in( on ventral lea sur ace. The sporan(iaare arran(ed on either side o placenta and are covered b indusium.

Spore 0ermination• :nder avorable condition in soil, spores (erminate b producin( small tube

called (erm tube. The (erm tube under(oes mitotic division to orm uniseriateflament.

• Rhi oids are developed at the base o uniseriate flament. :niseriate flamentunder(oes multiple divisions and develops into heart shaped structures called

prothallus. 7ature prothallus bears rhi oids at the base on ventral sur ace.0ametophyte

• The prothallus produced b (ermination o spore is called (ametoph te, +hichorms male and emale sex or(ans.

• The male sex or(ans 4 )ntheridia and emale sex or(ans 4 arche(onia are alsoound developed on the ventral sur ace o the prothallus. The arche(onia are situated belo+ apical notch and the

anheridia are situated on the posterior end o prothallus.• The mature prothallus is (reen small multicellular and dorsoventrall Aattened.

Se'ual reproduction• The prothalus is monocuous. The antheridia are small, (lobular, and sessile.


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• The antheridia remains covered b la er called acket, +hich encloses about #@ spermato oites out o +hichonl one use +ith e((.

• /ach spermato oites are coiled multiAa(ellated +ith posterior vesicle. Kesicle helps to s+im in +ater. Thespermato oites or male (ametes come out +hen anteridial +all(ets ruptured.

• The arche(onia are small Aask shaped and multicellular. The necko arche(onia consists o one binucleate neck canal cell and theKenter consists o one Kenter canal cell and e(( or ovum.

#ertilization

The spermato oites reach to the apexo arche(onia b s+immin( in +ater. The spermato oites (et the +athrou(h neck +hen the neck canal celland Kenter canal cell dissolved and

used +ith e((. The (ote is ormed +hich is diploid. The (ote under(oes multipledivisions and develops into embr o.=orm embr o root stem and leaves

develop and ne+ ern plant is produced. =rom the anterior superiorre(ion stem arises leaves arise rom anterior in erior re(ion and rootarises rom the posterior re(ion. ) ter development o embr o, theprothallus deca s, and (ametoph tic (eneration is fnished.

0ymnosperm0eneral characters$ mnosperms are exposed seeded ever(reen plants. The are considered as the earliest plants on theearth a ter pteridoph ta .there are about >0 (enera and >@5 species. The plant bod is sporoph tic and

di*erentiated in to root stem and leaves. The are heteroporous.

Pinus &Sallo(Lin(dom N planate


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Stem The stem is erect, aerial, c lindrical, +ood , branched. %ranches are dimorphic i.e. there are t+o t pes o branches in stem. -on( branches and hort branches

The branches, +hich come rom the main trunk, are called lon( branches. The sho+ unlimited (ro+th.-o+er lon( branches are lon(er and upper lon( branches are shorter. There ore, the plant appears asp ramid like.

The branches, +hich come rom the main trunk and rom lon( branches, are called short branches. Theare ver short the sho+ limited (ro+th. hort branches terminate into a cluster o (reen needles likeleaves. hort branches are replaced in ever @or # ear.-ea6es

The leaves are also dimorphic. There are t+o t pes o leaves.• =oliose lea • cal lea

#oliose lea6es" @ the are (reen, lon( needle like the arise rom short branches. The take part inphotos nthesis. Bn the basis o number o leaves, the species are o ollo+in( t pes.

hort branches havin( one oliose uni oliar spur P. monophylahort branches havin( t+o oliose bi oliar spur P. murkuriihort branches havin( three oliose tri oliar spur P. roburgtaiihort branches havin( our oliose oadri oliar spur P. uadrifoliahort branches havin( fve oliose penta oliar spur P. wallichiana

Scaly lea6es" @ the are scale like no (reen, dark bro+n in colour and are thin. The arise rom shortand lon( branches. The protect stem or branches b coverin(. .eproducti6e Structure2inus is monocious. The male and emale reproductive structures are called strobili or cone. The areproduced in di*erent branches o same plant.

4-% CO*%• The are ormed in (roup behind apical bud o lon( shoot or -on( %ranch.• The are small, @4 cm lon( and oval in shape.• The central axis o male cone is surrounded b spirall arran(ed microsporoph lls.• There are about 604150 microsporoph lls in each male cone.

icrospores &!ollen grains(• )t the base o each microsporoph lls there are t+o sac like structures called microsporan(ia.• Eithin each microsporan(ium, numerous spores are ormed called microspores.• Ehen microsporan(ial +all bursts, the spores or pollen (rains come out and appears ello+ mass called sho+er

o sulpher.ale gametophyte

• The male (ametoph te is ormed rom microspores.• The microspores are uninucleate, thick +alled havin( t+o +in(s.• The microspores are surrounded b three la ered +all exine, exointine and intine. The exointine expands to

orm +in(s.• Eithin microsporan(ium, microspore divides to orm our celled sta(e microspore.• ) ter pollination, a tube called pollen tube is developed rom our celled microspore. Eithin pollen tube t+o

male (ametes are produced orm (enerative cell.

#% 4-% CO*%• The emale cones are ormed in4(roup o 14 and to+ards the tip o the lon(

shoots.• The are lar(er than male cones i.e. 154@0 cm.• The central axis o emale cone is also surrounded b spirall arran(ed

me(asporoph lls.egaspore

• )t the base o me(asporoph lls ovules are produced.• -o+er e+ me(asporoph lls are sterile havin( no ovules.• /ach me(asporoph ll consists o small membranous scales called bract scales and

lar(e, thick, hard, and trian(ular scales attached on the dorsal side o bract scalecalled ovuli erous scales.


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• )t the base o ovuli erous scale, t+o o6ules are present on the dorsal side.• Eithin the ovule the me(aspore is developed.

#emale gametophyte• It is ormed rom me(aspore +ithin ovule.• The me(aspore divides multiple times to orm emale (ametoph te.• )rche(onia are ormed orm peripheral cells to+ards microp lar re(ion o emale (ametoph te.• /ach arche(onium consists o " celled neck, one Kenter canal cell and one lar(er e((.

#ertilization) ter one ear o pollination, ertili ation takes place. ' (ote is ormed and then developed into embr o. The embr oconsists o more than t+o cot ledons. ;e+ ovule is trans ormed into seed. :nder avorable condition, seeds alldo+n and ne+ plant (erminates.

4*0)OS!%. S

#amily : " Cruciferae

The cruci erae is also kno+n as mustard amil . This amil includes #>5 (enera and #@00 species. Theplants are ound abundantl in northern hemisphere and distributed +orld+ide. This amil includesve(etables Ao+ers and +ild varieties.

ome economicall important plants o this amil are%rassica compestris, 8TBRI9 Important or oil and ve(etable%. rapa, 8Turnip9 Important or ve(etable%. nigra, 8R)CB9 Important or oil and ve(etable%. oleracea, 8!):-I9 Important ve(etable and )nticancer "aphnus sativus 87:-)9 Important ve(etable 1epidium sativum 8!H)7 :R9 Important ve(etable

7abit habitat" )nnual or biannual or sometimes perennial, herbs, rarel shrubs, +ild or cultivated,terrestrial, mesoph tic.

.oot" Tap root and branched or modifed 8 usi orm e.(. "aphnus sativus , ;apio orm e.(. %.rapa 9, sometimesadventitious e.(. Roripa.

Stem" /rect, herbaceous, branched, c lindrical, solid, hair or (labrous, (reen, sometimes stem iscondensed or thickened 8 %. oleraces, ". sativs 9

-eaf" /xstipulate, petiolate or sessile, alternate, rarel opposite, simple, cauline and ramal or radical,l rate, lobed or entire, acute, (labrous, unicostate, reticulate venetation.

)n8orescence" racemose, receme or cor mb#lower" / bracteate, ebractiolate, pedicellate, hermaphrodite, complete, actinomorphic or (omorphic,

h po( nous, tetramerous, small, +hite or ello+.


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Caly'" sepals4 , pol sepalous, sepaloid, sepals in t+o +orls, @ in each +horl, hair or (labrous,imbricate aestivation.

Corolla" petals4 , pol petalous, cruci orm, each petal consists o limb and cla+, alternate +ith sepals,petaloid, valvet or imbricate aestivation.

4ndroecium" stamens46, tetramerous, pol androus. 4nther N bicelled, dithecous, basifxed, introse0ynoecium" !arpels4@, bicarpellar , s ncarpous. O6ary 4 superior, unilocular or bilocular,

placentation parietal. Style N short. Stigma N bilobed or (labrous.#ruit" ili uaSeed"


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0ynoecium" !arpel s N @, bicarpellar , s ncarpous. O6ary N superior, bilocular or tetramerous, axileplacentation, man ovules in each locule. Stigma N lobed or capitate. Style N lon( and sin(le

#ruit" %err or capsuleSeed"


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4ndroecium" tamens N 10, diadelphous or monoadelphous, rarel pol androus. 4nther" bilobed ordithecous, basifxed or dorsifxed, intorse.

0ynoecium" !arpel N 1, monocarpellar . O6ary" superior, unilocular, mar(inal placentation. Stylecurved. Stigma N capitate or hair .

#ruit" -e(ume or podSeed"


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caly'" Reduced or absent or sometimes hair like or scale like N @45.Corolla" 2etals N 5, (amopetalous, tubular, bilobed, valvet aestivation.4ndroecium" stamens N 5, pol androus, s n(enesious, epipetalous, )nther N dithecus, basifxed, introse.gynoecium" !arpels N @, bicarpellar , s ncarpous, Bvar N in eriorm unilocular, basal placentation, t le4lon(,

ti(ma4bifd.#ruit" c pselaSeed" dicot ledenous, nonendospermic

#loral formula

#loral diagram

Systemic position" !lass


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Systematic position!lass monocot ledonae

eries $lumaceae=amil $raminae

Diagnostic CharatersRoot 4 adventitious or fbrous. tem 4 erect and c lindrical. -eaves 4 narro+, lanceolate,parallel venation and consistin( o lea sheath and lea blade. InAorescence 4 spike o spikelets. 2erianth is represented b @ or # lodicules. tamens N # or 6, pol androus.)nther dithecus, versatile, !arpels N 1 or #, s ancarpus, Bvar superior, basalplancentation, sti(ma eather and bifd, ruit car opsis.

>)OT4 4*D %*/).O* %*T#O.%ST .%SOE.C%S

The orest is ver important rene+able natural resources. )bout #>O land area o ;epal is occupied borest. %ut accordin( to uno cial record onl 10O land area is occupied b orest.

)mportance of forest• The source o ra+ materials• It provides timber fre +ood +hich are used or various purposes like urniture, buildin( houses etc

it also provides odder, di*erent t pe o products like resin (um fber tubers etc.• In ;epal uel +ood is onl the source o ener( or domestic cookin( purpose.• The orest is bein( used as a urvedic medicines dru(s spices insecticides etc also used or

extractin( essential oils, +hich are used in soaps and cosmetics.• Karious industries depend on orest or their ra+ material like paper pl +ood actories tannin(

materials like d es (ums resin obtained rom plants are used in man industries•

The orest pla s a si(nifcant role in keepin( the atmospheric balance b consumin(coarbondioxide releasin( ox (en. It also control pollution• The (reen plants are the primar source o ener( or the other biotic components• The orest checks soil erosion and land de(radation. The roots hold the soil. The orest stops the

soil bein( eroded a+a b stron( +inds or rains.• The orest provides shelter to varieties o plats animals and microor(anism.• -ar(e numbers o people visit the orest or peace, beaut , and recreation. It provides natural

beaut .

Types of forest in *epal The orest o ;epal is classifed on the basis o (eo(raphical location and climatic characteristics.Tropical forest" The orest ound belo+ 1000 meter rom the seal level is tropical orest. It is ound in terai

belt. The orest o this belt is also called as


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4#O.%ST4T)O*2lantation and selection o use ul species, removal o undesired species, care, mana(ement andprotection o orest, implementation o la+s, utili ation o orest education and activatin( the communitand the people is called a orestation

D%#O.%ST4T)O*It is characteri ed b loss or cuttin( o orest trees +hich brin(s s series o un avorable chan(es in the

+hole biosphere.In the +orld @0. billion hector, orest is destro in( per ear. )mon( hi(h rate o de orestation ;epal isone. @." billion tons o !B@ is added in atmosphere per ear b de orestation. In ;epal durin( 1&65 to1&>&, ever ear >0000 hector orest +as destro ed. ) ter 1&>&, ever ear 1@000 hector orest +asdestro ed. ) ter @0 6 % . 1@00 hector orest +as declared.

Causes of deforestation• Bver production•


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Causes of increase in CO ;


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% ects of 4cid .ain)cid rain acidifes the soil )*ects Aora and auna)*ect human health )cidifes lakes and streams)*ect a uatic animals and ve(etation Reduces plant productivit)cid rain destro s orest Lills use ul bacteria and blue (reen al(aeIn +eden more than ten thousand lakes are acidic and in : ) thousands o lakes are acidic and in$erman "O orest +as cleared b acid rain.

Control• )ir pollution should be controlled• ) orestation should be dome• $ases comin( out o automobiles should be treated frst be ore dischar(in( out• )lternative sources o ener( should be used• !atal st process catal st converter should be used to chan(e toxic (ases

!ond %cosystem The pond is a small bod o standin( +ater and the pond ecos stem is complex interactions bet+een itsbiotic and abiotic components.4biotic component of pond ecosystem are"

/nvironmental actors li(ht, temperature, +ater The edaphic actors oilInor(anic !omponents are B @, !B @, ; @, nitrates, phosphates, carbonates etc.Br(anic components are carboh drates, proteins, amino acids, ats, nucleic acids

>iotic components are"!roducers

The producers are the a uatic (reen plants, +hich ma be divided into t+o (roups.icrophytes &phytoplan$tons(

The are microscopic autotrophs, +hich fx solar ener( . e(. $pirogyra , =ygnema, 'olvox, Oedogonium .acrophytes

The are lar(e plants, +hich manu acture complex ood. The are o ollo+in( t pesSubmerged plants" those, +hich are submer(ed in +ater, are submer(ed plants e( #ydrilla and >tricularia#loating plants those, +hich Aoat reel in +ater sur ace, are called Aoatin( plants e(. Pistia, ymphea an

A-olla)mmerged plants" those, +hich are rooted but emer(ent, are called immer(ed plants e( "anunculus , $agittariaand Typha

Consumers The consumers are those heterotrophic or(anisms, +hich consume producers as ood. The are also ollo+in(t pes!rimary consumers" These herbivorous animals depend upon autotrophic or(anisms such as microscopic planteaters or ooplanktons, 7ollusks, %eetles, ! clops, and


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FF,

Community The a((re(ation or assembles o livin( or(anisms havin( mutual relationship amon( themselves and to theirenvironment is called communit . )ssembles o plants is called plant communit and the assembla(e o animals iscalled animal communit .Characters of community•


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=ossili ation takes place in dead plants and animals to orm carbon compounds like coal and uel aspetrol or diesel.

ome amount o carbondioxide is also mixed durin( volcanic eruption and durin( minerali ation o rocks.

See and Draw necessary #igures

Botany Class 11

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Transcript of Botany Class 11