Plant Kingdom: Class 11 Biology Chapter 3 Hinglish mein

Talaab ke patthar se hari kaai khurcho, monsoon ke baad compound wall par jami velvet jaisi layer par ungli phero, hill trek par fern ki patti palat kar dekho, Shimla mein gira hua pine cone uthao, aur ghar lautte hue ek aam kha lo. Inmein se har organism Kingdom Plantae ka member hai. Yeh chapter is kingdom ko group by group dekhta hai, algae se lekar flowering plants tak, aur baar baar do sawaal poochhta hai: har group mein naya kya hai, aur botanists kaise tay karte hain ki koi plant kahan belong karta hai?

Aaj plant kise maana jaata hai

Chapter 2 mein tumne R.H. Whittaker ke five kingdoms (1969) dekhe: Monera, Protista, Fungi, Animalia aur Plantae. Purani two-kingdom schemes mein plant kingdom kahin zyada bada tha. Jis bhi cheez mein cell wall thi aur jo idhar udhar move nahi karti thi, use plants mein daal diya jaata tha, isliye bacteria, fungi aur photosynthetic 'blue-green algae' sab plants kehlaate the Fig. 3.1.

Ab Plantae kaafi chhota ho gaya hai. Fungi ka apna alag kingdom hai, aur Monera aur Protista ke wall wale members, jaise bacteria aur diatoms, apne hi kingdoms mein rehte hain. Blue-green algae prokaryotes hain, isliye aaj woh Monera mein cyanobacteria hain aur unhe algae gina hi nahi jaata. Plantae mein paanch groups bache hain: algae, bryophytes, pteridophytes, gymnosperms aur angiosperms.

Plants ko kaise classify kiya gaya hai

Bache hue plants ko sort karne ka kaam teen bade phases se guzra hai. Pehli schemes, jinhe ab artificial systems kehte hain, plants ko unhi baaton se sort karti thin jo aankh ko turant dikhti thin: growth form (tree, shrub ya herb), flower ka colour, kitni leaves hain aur unka shape kya hai. Linnaeus ne apna mashhoor system mainly androecium par banaya, yaani stamens ko gin kar aur unki arrangement dekh kar. Aisi schemes use karne mein jaldi hoti hain, lekin galat raah dikhati hain.

Socho ki plants ko sirf habit se group kiya jaaye. Ek 'climbers' group mein money plant, karela aur kaali mirch aa jaayenge, jo teen alag families se hain. Udhar ek hi species jo hawa wali pahaadi dhalaan par zameen par rengti hai lekin kisi sheltered garden mein seedhi ugti hai, do groups mein pahunch sakti hai. Kuch hi characters kareebi relatives ko alag kar dete hain aur anjaanon ko ek saath daal dete hain. Artificial systems vegetative features ko bhi reproductive features jitna hi weight dete the, jabki leaves aur stems environment ke hisaab se flowers se kahin zyada badalte hain.

Iske baad natural systems aaye. Yeh poochhte hain ki plants asal mein ek doosre se kitne kareebi related hain, yaani unki natural affinity kya hai, aur ise zyada se zyada characters se judge karte hain: bahari form, aur plant ke andar ke evidence bhi, ultrastructure aur anatomy se lekar embryology aur plant chemistry (phytochemistry) tak. Flowering plants ke liye sabse mashhoor natural system George Bentham aur Joseph Dalton Hooker ka banaya hua hai.

Aaj ka goal ek family tree hai. Phylogenetic system organisms ko descent ke hisaab se rakhta hai, isliye ek taxon mein ek hi common ancestor ke descendants hone chahiye. Jahan fossils branching dikhate hain, wahan yeh seedha hai; jahan fossil record chup hai, wahan taxonomists doosre evidence ki taraf jaate hain:

• Numerical taxonomy plant ke har observe kiye ja sakne wale character ko score karti hai, har score ko number ya code ke roop mein record karti hai, aur computer se poori table par plants ko compare karwati hai. Koi character doosre se zyada bhaari nahi hota, aur table mein sainkdon characters ho sakte hain (Example 3.1).
• Cytotaxonomy cells se mile evidence use karti hai: chromosomes ki sankhya, unka structure aur unka behaviour.
• Chemotaxonomy plants ke banaye chemicals, jaise pigments, oils ya alkaloids, ko compare karti hai, taaki woh cases suljhe jinhe sirf structure se clear nahi kiya ja sakta.

3.1 Algae

Jahan bhi light aur nami milti hai, wahan algae (शैवाल) mil jaati hain: talaab, nadiyon aur samundar mein, aur geele pattharon, nam mitti aur bheegi lakdi par hari parat ke roop mein bhi. Yeh Plantae ke sabse simple members hain. Har ek mein chlorophyll hota hai, yeh apna khaana khud banati hain aur inka ek thallus hota hai, yaani aisi body jo root, stem aur leaf mein divided nahi hoti. Kuch fungi ke saath milkar lichens banati hain, aur kuch to animals par bhi ugti hain: Central aur South America ke jungles mein tree sloths ke fur mein ek green alga rehti hai.11NCERT ke text mein 'sloth bear' likha hai. Documented case tree sloth ka hai, jiske fur mein green algae hoti hain; sloth bear ek Indian bhalu hai.

Algae ki bodies form aur size mein hairaan kar dene wali range dikhati hain Fig. 3.2. Chlamydomonas ek tairti hui cell hai. Volvox ek colony hai, cells ki ek khokhli ball. Ulothrix aur Spirogyra filaments hain, yaani ek ke baad ek judi cells. Doosre chhor par marine kelps bahut badi bodies banate hain jo paani ke neeche jungle bana dete hain.

Algae teen tareekon se reproduce karti hain. Vegetative reproduction mein thallus bas toot jaata hai, aur har tukda ek naya thallus ban jaata hai. Asexual reproduction mein yeh spores banati hain; sabse common zoospores hain, jinmein flagella hote hain, yeh kuch der tairte hain, phir tik kar naye plants ban jaate hain. Sexual reproduction mein do gametes judte hain, aur algae mein dono partners ke beech har level ka farq dikhta hai Fig. 3.3:

• Isogamy: dono partners same size ke hote hain. Ulothrix mein dono flagella se tairte hain; Spirogyra mein kisi mein flagella nahi hote.
• Anisogamy: dono partners tairte hain, lekin ek saaf taur par doosre se bada hota hai, jaise Eudorina ki kuch species mein.
• Oogamy: female gamete, yaani egg, bada hota hai aur ek jagah tika rehta hai, jabki ek bahut chhota male gamete tair kar uske paas aata hai, jaise Volvox aur Fucus mein.

Botanists algae ko teen main classes mein baante hain, mainly unke pigments aur unke stored food ke hisaab se; cell wall aur flagella is choice ko confirm karne mein madad karte hain. Classes hain Chlorophyceae (green), Phaeophyceae (brown) aur Rhodophyceae (red).

3.1.1 Chlorophyceae

Teeno classes mein green algae land plants se sabse zyada milti hain: inka grass-green colour unhi do pigments, chlorophyll a aur b, se aata hai, jo definite chloroplasts mein hote hain. Inki bodies single cells, colonies ya filaments ho sakti hain. Microscope ke neeche chloroplast ka shape species pehchaanne ka achha clue hai Fig. 3.4: cup, spiral ribbon, net (reticulate), kai chhote discs, ya ek flat plate.

Zyaadatar chloroplasts mein ek ya zyada pyrenoids hote hain, yaani protein se bani storage bodies jinke chaaron taraf starch hota hai; kuch species oil droplets bhi rakhti hain. Mazboot cell wall ki do layers hoti hain: bahar pectose aur andar cellulose.

Reproduction mein algae ke saare tareeke dikhte hain. Tukde toot kar phir ug jaate hain; zoosporangia se flagella wale zoospores nikalte hain; aur species ke hisaab se gametes isogamy, anisogamy ya oogamy se fuse hote hain. Jaane-pehchaane genera hain Chara, Spirogyra, Ulothrix, Volvox aur Chlamydomonas.

3.1.2 Phaeophyceae

Brown algae mein rocky coasts ki kai badi seaweeds aati hain, aur lagbhag sab marine hain. Size Ectocarpus ke branched filaments se lekar das-das metre lambe kelps tak hota hai.22NCERT kelps ki height 100 m tak batata hai, aur exam questions bhi yahi figure follow karte hain. Measured giant kelps aam taur par lagbhag 45–50 m tak report hote hain. Ek badi brown alga plant na hote hue bhi kuch kuch plant jaisi organised hoti hai. Ek holdfast chattan ko pakadta hai, usse stipe naam ka ek stalk uthta hai, aur leaf jaise fronds photosynthesis karte hain (Fig. 3.2 ka last step).

Brown colour pigments ke balance ki baat hai. Chlorophyll a aur c ke saath in algae mein carotenoids aur xanthophylls hote hain, aur ek xanthophyll, fucoxanthin, shade tay karta hai: yeh jitna zyada, alga utni brown, olive green se lekar gehre brown tak. Food complex carbohydrates, laminarin ya mannitol, ke roop mein store hota hai. Har cell mein cellulose wall hoti hai, aam taur par bahar algin ki jelly jaisi coating ke saath, aur andar plastids, ek bada central vacuole aur ek nucleus hota hai.

Fragmentation ke alawa brown algae pear-shaped zoospores chhodti hain, har ek mein alag lambai ke do flagella hote hain jo cell ki tip par nahi balki side par jude hote hain Fig. 3.5. Gametes bhi lagbhag waise hi dikhte hain: pear-shaped (pyriform), do lateral flagella ke saath. Alag species mein isogamy, anisogamy ya oogamy dikhti hai; oogamous species apne gametes ko oogonium ke andar fuse karti hain, baaki khule paani mein. Fucus, Sargassum, Laminaria, Dictyota aur Ectocarpus common examples hain.

3.1.3 Rhodophyceae

Red algae ka colour ek red pigment, r-phycoerythrin, se aata hai. Zyaadatar marine hain aur garam samundaron mein sabse zyada milti hain. Kai surface ke paas tez roshni wale paani mein ugti hain, phir bhi kuch aisi gehraai par panapti hain jahan bahut kam light bachti hai, kisi bhi doosri seaweed se zyada gehre Fig. 3.6. Phycoerythrin isko samjhata hai. Yeh woh blue-green light absorb karta hai jo gehre paani tak pahunchti hai aur us energy ko photosynthesis ke liye aage de deta hai.

Red alga ki life mein ek bhi cell tairti nahi. Iske asexual spores aur gametes mein flagella nahi hote, sexual reproduction hamesha oogamous hota hai, aur fertilisation ke baad development ka ek complex sequence shuru hota hai. Yeh fragmentation se bhi badhti hain. Zyaadatar ke multicellular thalli hote hain, kuch kaafi complex, aur yeh floridean starch store karti hain, ek aisa reserve jo amylopectin aur glycogen jaisa bana hota hai. Common examples hain Gelidium, Gracilaria, Porphyra aur Polysiphonia.

Table 3.3 teeno classes ko agal bagal rakhta hai. Ek class describe karne ke liye column ko upar se neeche padho, ya kisi ek feature par teeno ko compare karne ke liye row ko padho.

3.2 Bryophytes

Monsoon ke kuch hafton baad Darjeeling ya Munnar jaise hill towns mein chhaon wali deewarein, tree trunks aur chattanein velvet jaisi hari ho jaati hain. Is velvet ka zyaadatar hissa bryophytes se bana hota hai: mosses aur liverworts. Inhe nam, humid, chhaon wali jagahein chahiye, aur inhe aksar plant kingdom ke amphibians kaha jaata hai: yeh land par rehte hain, lekin inka sexual reproduction paani par depend karta hai.

Dhyaan se dekho to bryophyte mein roots, stem aur leaves lagte hain. Lekin hote nahi, kam se kam true wale to nahi, kyunki ismein vascular tissue nahi hota; iske root jaise, stem jaise aur leaf jaise parts bas un organs se milte julte hain. Phir bhi body alga se zyada differentiated hoti hai. Yeh thallus jaisi hoti hai, zameen par leti hui (prostrate) ya seedhi khadi (erect), aur ek ya kai cells wale rhizoids ise tikaate hain.

Jo hara plant tumhe dikhta hai, chahe leafy moss shoot ho ya flat liverwort, woh haploid ($n$) hota hai. Yeh sex cells banata hai, isliye ise gametophyte kehte hain. Iske sex organs kai algae ki tarah single cells nahi, balki multicellular structures hote hain Fig. 3.7:

• Antheridium (male): kai antherozoids chhodta hai, har ek do flagella se tairta hai.
• Archegonium (female): lambi gardan aur phoole hue base wala ek flask, jismein ek single egg hota hai.

Baarish agla stage shuru karti hai. Antherozoids plant par paani ki patli layer mein tairte hain, jab tak ek archegonium ki gardan mein ghus kar egg se fuse nahi ho jaata, aur diploid ($2n$) zygote banta hai. Iske baad jo hota hai woh naya hai. Turant meiosis se divide hone ke bajaye zygote mitosis se badh kar ek multicellular sporophyte ban jaata hai, ek doosri generation jo kabhi apne parent ko nahi chhodti: yeh hare gametophyte se judi rehti hai aur usi se poshan leti hai. Baad mein hi sporophyte ki kuch cells meiosis karti hain, aur haploid spores banate hain jo naye gametophytes mein badal jaate hain.

Inki direct economic value kam hai, ek khaas exception ke saath: peat. Moss Sphagnum ke bogs peat banate hain, jise lambe samay se kaat kar fuel ki tarah jalaya jaata raha hai, aur sookha Sphagnum itna paani pakadta hai ki lambe safar ke liye zinda plants ko pack karne mein iska use hota aaya hai. Kuch mosses ko herbivorous mammals charte hain aur birds khaate hain.

Inka ecological role aur bhi bada hai. Nayi road cutting se khule ek nange boulder ke baare mein socho. Us par aam taur par sabse pehle lichens aur mosses baste hain. Saalon tak inka badhna aur sadna chattan ki surface ko bhurbhura kar deta hai aur dhool aur organic matter ko pakad leta hai, jisse ek patli mitti banti hai jismein grasses aur baad mein shrubs jad pakad sakte hain. Isliye yeh plant succession mein khaas players hain. Dhalaanon par moss ka mota carpet girti boondon ki chot jhel leta hai, isliye kam mitti behti hai. Bryophytes do groups mein aate hain: liverworts aur mosses.

3.2.1 Liverworts

Liverworts wahan dhoondho jahan kabhi poori tarah sookha na ho: streams ke kinaare, daldali ya nam mitti par, tree bark par aur ghane jungle ki chhaon mein. Marchantia mein body ek flat, forked thallus hai. Yeh dorsiventral hai, yaani iski upar aur neeche ki surfaces alag hoti hain, aur yeh zameen se chipki rehti hai Fig. 3.8. Leafy liverworts bilkul alag dikhte hain: stem jaise axis par do rows mein chhote leaf jaise scales hote hain.

Liverwort bina sex ke bhi fail sakta hai. Sabse simple tareeka hai ki purana thallus tukdon mein toot jaaye jo badhte rahein. Zyada saaf tareeke mein gemmae (singular gemma) use hote hain: chhote, hare, multicellular buds jo upar ki surface par gemma cups ke andar bante hain. Baarish ki boondein inhe uchhaal kar bahar nikaalti hain, aur nam zameen par girne wala har gemma ek naya plant ban jaata hai, jo genetically apne parent jaisa hi hota hai.

Species ke hisaab se, ek hi thallus par antheridia aur archegonia dono ho sakte hain, ya sexes alag thalli par ug sakte hain, jaise Marchantia mein, jahan yeh stalk wali, chhatri jaisi branches par hote hain. Dono hi case mein, fertilisation ke baad banne wala sporophyte teen parts se bana hota hai: gametophyte mein dhansa ek foot, ek chhota stalk (seta) aur ek capsule jismein meiosis spores banata hai. Nikle hue spores germinate hokar naye, free-living gametophytes bante hain.

3.2.2 Mosses

Mosses mein bhi life cycle mein gametophyte hi haavi hota hai. Yeh do stages mein badhta hai, aur dono haploid hain:

• Protonema, juvenile stage: germinate hote spore se sabse pehle yahi banta hai. Mitti par rengte dhaagon ki ek baareek hari chatai socho; yeh branch karte hain aur aam taur par filamentous hote hain.
• Leafy stage, adult: secondary protonema ki sides par buds bante hain, aur har bud upar badh kar ek patla shoot ban jaata hai. Iski leaves axis ke chaaron taraf spiral mein lagi hoti hain, aur multicellular, branched rhizoids ise mitti mein tikaate hain. Sirf yahi stage sex organs banata hai.

Moss sporophyte mein bhi liverwort jaise teen parts hote hain, foot, seta aur capsule, lekin yeh zyada complex hota hai aur spores bikherne mein khaas taur par achha hota hai. Kai mosses mein capsule ke munh ke chaaron taraf daanton ki ek ring sookhi hawa mein khul jaati hai, jab spores door tak jaate hain, aur nam hawa mein phir band ho jaati hai. Andar ke spores meiosis se bante hain. Sporophyte khud leafy shoot ki tip par bane zygote se ugta hai, jahan antheridia aur archegonia develop hote hain. Mosses bina sex ke bhi badh sakte hain, fragmentation se aur secondary protonema par budding se. Funaria, Polytrichum aur Sphagnum common mosses hain.

3.3 Pteridophytes

Western Ghats aur north-east ki chhaon wali road cuttings ferns se bhari rehti hain, aur streams ke kinaare horsetails ugte hain; dono pteridophytes hain. Log inhe ornamentals ki tarah ugaate hain, kuch ko medicines ki tarah use karte hain aur kuch ko dhalaanon par soil-binders ki tarah lagaate hain. Zyaadatar ko thandi, nam, chhaon wali jagahein chahiye, halaanki kuch reteeli mitti par bhi chal jaate hain.

Pteridophytes ne evolution mein ek badi chhalaang lagaayi: yeh vascular tissues wale pehle land plants hain, paani le jaane ke liye xylem aur food le jaane ke liye phloem. In tissues ko tum Chapter 6 mein padhoge. Vascular tissue poora body plan badal deta hai, kyunki jo plant paani upar utha sake aur food ko lambi doori tak le ja sake, woh bada ho sakta hai aur true organs bana sakta hai.

Pteridophytes bryophytes wali arrangement ko ulat dete hain. Jo fern tumhe dikhta hai woh sporophyte ($2n$) hai: iske true roots, stems aur leaves hote hain, har ek mein achhi tarah develop hua vascular tissue, jabki gametophyte simat kar ek chhoti, kam samay wali stage reh gaya hai. Leaf ka size bahut badalta hai: Selaginella mein microphylls naam ki chhoti leaves hoti hain, jabki fern ka frond ek badi leaf, yaani macrophyll, hai.

Spores sporangia mein bante hain, jinke andar spore mother cells meiosis se divide hoti hain. Sporangia random bikhre nahi hote: har ek ek leaf jaise sporophyll par, ya uske angle mein, hota hai. Selaginella aur Equisetum mein sporophylls compact cones, yaani strobili, mein bhare hote hain; ferns mein yeh normal leaves jaise dikhte hain, jinke neeche sori hote hain.

Har spore ek aisa gametophyte banata hai jise tum aasaani se nazarandaaz kar sakte ho: prothallus, ek centimetre se chhoti flat hari plate, ferns mein aksar dil ke shape ki Fig. 3.9. Yeh multicellular hai, apna khaana khud banata hai aur apne dam par jeeta hai, lekin aasaani se sookh jaata hai, isliye sirf thandi, nam aur chhaon wali jagahon par hi bachta hai. Iske neeche ki taraf antheridia aur archegonia hote hain. Antherozoids archegonium tak sirf paani ki patli layer mein tair kar hi pahunch sakte hain; inmein se ek egg ko fertilise karta hai, aur zygote ek naye sporophyte mein badalta hai jismein organs achhi tarah differentiated hote hain, yahi dominant phase hai. Kamzor gametophyte aur tairte gametes ki wajah se aaj ke pteridophytes kaafi chhote geographical regions tak hi simit rehte hain.

Selaginella aur Salvinia ko dhyaan se dekhna chahiye, kyunki yeh usual pattern todte hain. Ek typical pteridophyte homosporous hota hai: uske saare spores ek jaise hote hain. Yeh do genera iske bajaye heterospory dikhate hain, yaani bade megaspores banate hain, jo female gametophytes bante hain, aur chhote microspores, jo male gametophytes bante hain Fig. 3.10.

Do aur aadatein inhe khaas banati hain. Female gametophyte ko bas gira kar apne bharose nahi chhoda jaata, balki woh kuch samay parent sporophyte par hi rehta hai, aur zygote us female gametophyte ke andar hi ek young embryo mein badhta hai. Yeh seed habit ka pehla roop hai, jo plant evolution ke bade kadmon mein se ek hai. Seed, jise tum gymnosperms mein dekhoge, female gametophyte aur young embryo ko tab tak parent par rakhta hai jab tak woh achhi tarah protected na ho jaayein.

Pteridophytes ko traditionally chaar classes mein rakha jaata hai (Table 3.5).

3.4 Gymnosperms

Gymnosperm (अनावृतबीजी) shabd do Greek words ko jodta hai, gymnos (naked) aur sperma (seed). Inke ovules ko koi ovary wall nahi dhakti; yeh shuru se hi sporophylls par khule pade rehte hain aur fertilisation ke baad bhi khule rehte hain, isliye inse bane seeds bina dhake, yaani naked, hote hain. Himachal ke deodar forests, Uttarakhand ki pahaadiyon ke chir pine aur poore India ke gardens mein lage palm jaise Cycas, sab gymnosperms hain.

Gymnosperms shrubs se lekar Earth ke kuch sabse lambe trees tak hote hain: sabse lamba jaana-pehchaana zinda tree ek coast redwood, Sequoia, hai, lagbhag 116 m ooncha. Zyaadatar mein tap roots hoti hain. Cycas aur pine ko agal bagal imagine karo, to dikhega ki yeh kitne alag ho sakte hain:

• Cycas: bina branch wala trunk jiske upar badi pinnate (compound) leaves ka mukut hota hai jo kuch saal tak tikti hain, aur surface ke paas chhoti, specialised coralloid roots jinmein nitrogen ($\mathrm{N}{\phantom{X}}_2$) fix karne wale cyanobacteria rehte hain.
• Pinus: Cedrus jaisa branched tree, simple needle leaves ke saath, aur aisi roots jo fungi ke saath partnership mein mycorrhiza ke roop mein rehti hain.

Gymnosperm leaves temperature, humidity aur hawa ki extreme conditions jhel leti hain. Pine needle mushkilon ke liye bani leaf hai. Iska patla shape surface area kam rakhta hai, mota cuticle ise seal karta hai, aur iske stomata gaddhon mein dhanse hote hain, sukhaane wali hawa se door.

Reproduction cones (strobili) par tika hai. Cone ek axis hai jiske chaaron taraf sporophylls spiral mein lage hote hain, dheele ya kas kar bhare hue, aur sporophylls par sporangia hote hain. Selaginella ki tarah har gymnosperm heterosporous hai, jo do tarah ke haploid spores, microspores aur megaspores, banata hai, isliye cones bhi do tarah ke hote hain:

• Male cones (microsporangiate strobili) par microsporangia wale microsporophylls hote hain. Microsporangium ke andar ek microspore aisa male gametophyte banta hai jo itna reduced hai ki usmein bas kuch hi cells hoti hain: pollen grain.
• Female cones (macrosporangiate strobili) par megasporophylls hote hain jin par ovules lage hote hain.

Pinus mein dono tarah ke cones ek hi tree par ugte hain. Cycas alag hai: male cones kuch plants par bante hain, aur megasporophylls, jo compact cone mein bane hone ke bajaye dheele guchhe mein hote hain, doosre plants par bante hain.

Ab ek ovule ke andar dekho Fig. 3.11. Iska core nucellus hai, yaani megasporangium, jo integuments naam ki protective layers mein lipta hota hai. Nucellus ki ek cell megaspore mother cell banti hai, jo meiosis se divide hokar chaar megaspores banati hai. Chaaron mein se sirf ek bachta hai. Megasporangium ke andar hi yeh ek multicellular female gametophyte banta hai jis par do ya zyada archegonia hote hain.

Dekho gametophytes ke saath kya hua hai. Moss mein gametophyte poora plant tha, aur fern mein ek free-living prothallus; gymnosperm mein dono gametophytes sporophyte par sporangia ke andar hi rehte hain aur kabhi apne dam par nahi jeete. Le jaane ka kaam hawa karti hai. Microsporangia se pollen ke baadal nikalte hain, aur jo kuch grains micropyle, yaani ovule ke munh, par tikte hain woh ek pollen tube bhejte hain. Tube archegonia ki taraf badhti hai aur unki gardan ke paas apne male gametes chhod deti hai, isliye fertilisation ke liye paani nahi chahiye.33Pine mein pollination tab hota hai jab ovule abhi young hota hai; female gametophyte mature hota hai, aur fertilisation lagbhag ek saal baad hota hai. Fertilisation ke baad zygote ek embryo banta hai, aur ovule mature hokar seed ban jaata hai. Group ke naam ke mutaabik, us seed ko koi fruit nahi dhakta.

3.5 Angiosperms

Angiosperms (आवृतबीजी) flowering plants hain, aur flower inki pehchaan wali khoj hai: pollen grains aur ovules dono iske andar bante hain. Ovules ek ovary mein band rehte hain, aur fertilisation ke baad seeds bhi band hi rehte hain, ab ek fruit ke andar Fig. 3.12. Isi farq ki wajah se, yaani khule scale par pade seeds ke bajaye fruit ke andar seeds, gymnosperms aur angiosperms ko alag classify kiya jaata hai, halaanki dono seeds banate hain.

Sankhya mein koi doosra plant group inke aas paas bhi nahi hai: angiosperms land ke lagbhag har habitat mein, aur meethe aur khaare paani ke kai habitats mein fail chuke hain. Size bhi koi seema nahi hai, Wolffia se, jo bina root ka tairta plant hai, lagbhag ek millimetre se bhi chhota, aur sabse chhota flowering plant hai, lekin lagbhag 100 m oonche Eucalyptus trees tak. Hamari lagbhag saari food crops, zyaadatar chaara, kaafi fuel wood aur medicine, timber aur cotton aur jute jaise fibres inhi se aate hain.

Flowering plants do classes mein aate hain, jinka naam embryo mein seed leaves (cotyledons) ki sankhya par rakha gaya hai: dicotyledons mein do hote hain aur monocotyledons mein ek. Neeche ki comparison field mein jaldi pehchaan ke clues deti hai; in features ko tum Chapter 5 mein theek se padhoge.

Poore plant kingdom par ek nazar

Chaar land-plant groups ko line mein lagao to do trends saaf dikhte hain Fig. 3.13. Gametophyte chhota hota jaata hai, moss mein poore leafy plant se lekar flower ke andar chhupi kuch cells tak. Sporophyte bada hota jaata hai, gametophyte par sawaar capsule se lekar jungle ke tree tak. Saath hi, pollen aur pollen tubes aane ke baad fertilisation ke liye paani par dependence khatam ho jaati hai, aur seed aata hai jo baad mein fruit mein lipat jaata hai.

Neeche ka sorter un do skills ki practice karwata hai jo exam questions sabse zyada test karte hain: kisi genus ko uske group mein rakhna, aur kisi structure ki ploidy batana.