PK k>]_rels/PK k>] docProps/PK k>]ppt/PK k>] ppt/_rels/PK k>] ppt/charts/PK k>]ppt/charts/_rels/PK k>]ppt/embeddings/PK k>] ppt/media/PK k>]ppt/slideLayouts/PK k>]ppt/slideLayouts/_rels/PK k>]ppt/slideMasters/PK k>]ppt/slideMasters/_rels/PK k>] ppt/slides/PK k>]ppt/slides/_rels/PK k>] ppt/theme/PK k>]ppt/notesMasters/PK k>]ppt/notesMasters/_rels/PK k>]ppt/notesSlides/PK k>]ppt/notesSlides/_rels/PK k>]"˩[Content_Types].xml PK k>]]] _rels/.rels PK k>]docProps/app.xml 0 0 Microsoft Office PowerPoint On-screen Show (16:9) 0 12 12 0 0 false Fonts Used 2 Theme 1 Slide Titles 12 Arial Calibri Office Theme Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12 PptxGenJS false false false 16.0000 PK k>]&O4docProps/core.xml PptxGenJS Presentation PptxGenJS Presentation PptxGenJS PptxGenJS 1 2026-08-14T07:51:23Z 2026-08-14T07:51:23Z PK k>]* * ppt/_rels/presentation.xml.rels PK k>]Oݨ ppt/theme/theme1.xmlPK k>] ppt/presentation.xml PK k>]Xppt/presProps.xml PK k>]ppt/tableStyles.xml PK k>]D >00ppt/viewProps.xml PK k>]H7t!ppt/slideLayouts/slideLayout1.xml PK k>]ђ77,ppt/slideLayouts/_rels/slideLayout1.xml.rels PK k>]}}ppt/slides/slide1.xml BOTANY · SPERMATOPHYTAGymnospermsThe Naked-Seeded Plants — Characters, Classification & SignificanceGymnospermae (gymnos = naked; sperma = seed)Chapter 1 | Introduction to Gymnosperms11PK k>]3 ppt/slides/_rels/slide1.xml.rels PK k>].ppt/notesSlides/notesSlide1.xml 1PK k>]:A*ppt/notesSlides/_rels/notesSlide1.xml.rels PK k>]uIIppt/slides/slide2.xml INTRODUCTIONWhat Are Gymnosperms?Gymnospermae (gymnos = naked; sperma = seed) constitutes one of the two sub-divisions of the division Spermatophyta. It includes all autophytic green plants having their seeds exposed on the megasporophylls, i.e. the carpels.Systematic position: Gymnosperms lie between Pteridophyta and Angiospermae — bearing close affinities with the pteridophytes on one hand and the angiosperms on the other.Spermatophyta(Seed Plants)Gymnospermae(naked seeds)Angiospermae(covered seeds)Chamberlain (1935) called this sub-division “Gymnospermae.”63Genera worldwide722Living species16 / 52Genera / Species in IndiaSource: Razitaza & Sahni (1960)Gymnosperms — Introduction2PK k>]2- ppt/slides/_rels/slide2.xml.rels PK k>]ppt/notesSlides/notesSlide2.xml 2PK k>]xշ*ppt/notesSlides/_rels/notesSlide2.xml.rels PK k>]@@@ppt/slides/slide3.xml SECTION 1.1Characteristic Features — Habit & Vascular System(a)HabitMajority are tall, woody, perennial trees or rarely shrubs. Sporophytes are much larger and independent (when mature); true roots, stems and leaves are present.(b)ReproductionVegetative reproduction by cuttings, layering, etc. Growth rate is slow; dispersal of spores occurs only by wind, or by human agency (except Gnetum).(c)Vascular TissueXylem vessels are absent (except Gnetum); tracheids have bordered pits. Phloem has sieve tubes only — companion cells are absent, hence chances of self-fertilization are reduced.(d)Stem AnatomyVascular bundles are conjoint, collateral and open — arranged in a ring. Xylem is arranged in a ring producing considerable secondary wood; secondary growth takes place.Gymnosperms — Characteristic Features (1/2)3PK k>]W/ ppt/slides/_rels/slide3.xml.rels PK k>]K |Őppt/notesSlides/notesSlide3.xml 3PK k>]9 Y*ppt/notesSlides/_rels/notesSlide3.xml.rels PK k>]'J:J:ppt/slides/slide4.xml SECTION 1.1Characteristic Features — Reproductive Biology(e)Leaves are usually dimorphic — brown scale leaves and green foliage leaves which are evergreen and provided with thick cuticle. Two types: microphyllous or the larger megaphyllous.(f)Flowers are unisexual, reduced and naked, i.e. without perianth (except Gnetum). Male and female flowers are represented by microsporophylls i.e. stamens and megasporophylls i.e. carpels respectively, forming male cones and female strobili.(g)Male gametes are either ciliated and motile (= sperms), as seen in Cycas and Ginkgo, or non-ciliated and non-motile, as in Pinus, Gnetum, etc.(h)Endosperm formation takes place within the female gametophyte before fertilization — the endosperm tissue is haploid (except partly in Gnetum).(i)Embryo development begins at the end of a long suspensor; later differentiates into upper (haustorial), middle (suspensorial) and basal (embryonal) regions. Polyembryony is common.(k)True seeds are always present but borne uncovered or naked — not enclosed in fruits, since ovary (formed by closed carpels) is absent.Gymnosperms — Characteristic Features (2/2)4PK k>]` ppt/slides/_rels/slide4.xml.rels PK k>]vsppt/notesSlides/notesSlide4.xml 4PK k>]J *ppt/notesSlides/_rels/notesSlide4.xml.rels PK k>]yDDppt/slides/slide5.xml SECTION 1.2Gymnosperms vs. PteridophytesGYMNOSPERMSPTERIDOPHYTESTrue roots present.Adventitious roots present; mostly underground rhizomatous stem.Heterosporous — produce microspores and megaspores.Generally homosporous; some are heterosporous.Seeds are produced (naked-seeded plants).No seeds are produced.Pollen tube produced on germination of pollen grains.No pollen tube; spores germinate directly.Megasporangium protected by an integument.Megasporangium not protected by an integument.Neck canal cells absent in archegonia (absent in Gnetum).Neck canal cells present in archegonia.Comparative Account — Gymnosperms & Pteridophytes5PK k>]5 ppt/slides/_rels/slide5.xml.rels PK k>]W8ppt/notesSlides/notesSlide5.xml 5PK k>]Qe*ppt/notesSlides/_rels/notesSlide5.xml.rels PK k>]UfpMpMppt/slides/slide6.xml SECTION 1.4Gymnosperms vs. AngiospermsGYMNOSPERMSANGIOSPERMSWoody perennial trees or shrubs only.Annual, biennial or perennial — herbs, shrubs or trees.Flowers unisexual, simple, without perianth (except Gnetum).Flowers unisexual or bisexual, with or without perianth.Ovules freely exposed on carpels — seeds remain naked.Carpels form an ovarian chamber; ovules and seeds enclosed.Pollen grains carried by wind directly to the micropyle.Pollen carried by various agents; deposited on the stigma.Male gametophyte: 2 or 1 prothallial cell, tube nucleus, 2 male nuclei/sperms.Male gametophyte further reduced: only 2 male nuclei and a tube nucleus.Endosperm (n) formed before fertilization — haploid.Endosperm (3n) formed after fertilization — triploid.Embryo: 1 to many cotyledons; often polyembryonic.Embryo: 1 or 2 cotyledons; usually one embryo per ovule.Comparative Account — Gymnosperms & Angiosperms6PK k>]ج+ ppt/slides/_rels/slide6.xml.rels PK k>]zppt/notesSlides/notesSlide6.xml 6PK k>]=|*ppt/notesSlides/_rels/notesSlide6.xml.rels PK k>]`ggppt/slides/slide7.xml SECTION 1.5Classification of GymnospermsC. J. Chamberlain (1935) — based on morphological & anatomical charactersGYMNOSPERMAEI. CYCADOPHYTASmaller plants; unbranched stem; large pinnate compound leaves; sporophylls in simple cones.II. CONIFEROPHYTALarger plants; branched stem; simple leaves; microsporophylls in simple, megasporophylls in compound cones.Cycadofilicales All extinct (Carboniferous)Bennettitales Extinct (Mesozoic)Cycadales Extinct + living, e.g. Cycas, ZamiaCordaitales All extinct (Paleozoic)Ginkgoales One living species — Ginkgo bilobaConiferales Pinus, Abies, Cedrus, Thuja, Araucaria...Gnetales Living genera — Gnetum, EphedraClassification — Chamberlain (1935)7PK k>]F ppt/slides/_rels/slide7.xml.rels PK k>])lppt/notesSlides/notesSlide7.xml 7PK k>]|g*ppt/notesSlides/_rels/notesSlide7.xml.rels PK k>]-SSppt/slides/slide8.xml SECTION 1.5 (CONTD.)Other Classification SystemsB. Sahni (1920)Two groups by seed position• Phyllospermae — leaf-borne seeds (Pteridospermae, Cycadales, Bennettitales)• Stachyospermae — stem-borne seeds (Cordaitales, Ginkgoales, Coniferales, Gnetales)C. A. Arnold (1948)Three classes• Cycadophyta — Pteridospermae, Cycadales, Cycadeoidales• Coniferophyta — Cordaitales, Ginkgoales, Taxales, Coniferales• Chlamydospermophyta — Ephedrales, GnetalesPilger & Melchior (1954)Four classes• Cycadopsida · Coniferopsida · Taxopsida · Chlamydospermae• (followed also by K. R. Sporne, 1965)D. D. Pant (1957)Three divisions• Cycadophyta · Chlamydospermophyta · ConiferophytaAll major systems converge on two core lineages — a cycad-like group and a conifer-like group — differing mainly in how fossil orders and Gnetales are placed.Classification — Comparative Systems8PK k>]6 ppt/slides/_rels/slide8.xml.rels PK k>]iސppt/notesSlides/notesSlide8.xml 8PK k>]pO*ppt/notesSlides/_rels/notesSlide8.xml.rels PK k>]߂r(W(Wppt/slides/slide9.xml SECTIONS 1.6 & 1.7Phylogenetic Relationship & AffinitiesPTERIDOPHYTAFilicinae (fern-like ancestors)GYMNOSPERMSCycadophyta + ConiferophytaANGIOSPERMSFlowering plantsAffinities with Pteridophytes• Sporophytic & gametophytic generations alternate in both groups.• Cycads resemble ferns in compound leaves and circinate vernation.• Companion cells absent in phloem, tracheae absent in xylem (both, except Gnetum).• Heterospory resembles Selaginella, Isoetes, Marsilea.• Cycadales show multiflagellate motile sperms, as in some pteridophytes.Affinities with Angiosperms• Similar habit — trees or shrubs, woody perennials.• Unisexual, apetalous flowers with micro- & mega-sporophylls (stamens & carpels).• Presence of a pollen tube carrying male gametes to the egg.• Megaspore is retained within the megasporangium and develops into the female gametophyte in situ.Phylogenetic note: Cordaitales are believed to have given rise to the Coniferales and Ginkgoales; the Gnetales may represent an offshoot of the Coniferophyta line.Phylogeny & Affinities of Gymnosperms9PK k>]>$ ppt/slides/_rels/slide9.xml.rels PK k>]qppt/notesSlides/notesSlide9.xml 9PK k>]1*ppt/notesSlides/_rels/notesSlide9.xml.rels PK k>]00ppt/slides/slide10.xml SECTION 1.8Economic Importance of GymnospermsTimber & ResinPinus (Pinaceae) is a major commercial timber source — used for construction, furniture, poles and packing cases. Pinus roxburghii (‘chir’) yields turpentine and resin; fossilised resin of Pinus succinifera is amber, prized in jewellery.Food & NutritionCycas circinalis produces an arrowroot-type sago from its tuber and seeds. Seeds of Gnetum and Pinus gerardiana (chilgoza) are eaten after roasting and are highly nourishing; Gnetum ula seeds yield a cooking oil.MedicineEphedra yields ephedrine, used for treating asthma and bronchial troubles. Pinus resin is used internally for stomach troubles and externally as a plaster for glandular swellings.Fibre & Other UsesThe bark of Gnetum gives a strong fibre for fishing nets, lines and ropes. Cycas revoluta is a decorative garden plant; Gnetum montanum seeds are reputed to possess pesticidal properties.Economic Importance of Gymnosperms10PK k>]Ѳ!ppt/slides/_rels/slide10.xml.rels PK k>]O ppt/notesSlides/notesSlide10.xml 10PK k>]T+ppt/notesSlides/_rels/notesSlide10.xml.rels PK k>]KW<<ppt/slides/slide11.xml KEY TAKEAWAYSGymnosperms at a Glance1Naked-seeded, woody, wind-pollinated seed plants forming a bridge between Pteridophyta and Angiospermae.2Distinguished by tracheid-only xylem, companion-cell-free phloem, and haploid endosperm formed before fertilization.3Classified by Chamberlain into Cycadophyta and Coniferophyta, each divided into fossil and living orders.4Show fern-like affinities (cycads) and angiosperm-like affinities (unisexual cones, pollen tube) simultaneously.5Of major economic value — timber, resin, food, medicine (ephedrine) and fibre.Summary1111PK k>];!ppt/slides/_rels/slide11.xml.rels PK k>]s6ӑ ppt/notesSlides/notesSlide11.xml 11PK k>]O+ppt/notesSlides/_rels/notesSlide11.xml.rels PK k>]M>WWppt/slides/slide12.xml Thank YouQuestions & DiscussionGymnosperms1212PK k>]c!ppt/slides/_rels/slide12.xml.rels PK k>]*)@ ppt/notesSlides/notesSlide12.xml 12PK k>]Fb+ppt/notesSlides/_rels/notesSlide12.xml.rels PK k>]K !ppt/slideMasters/slideMaster1.xml PK k>]N),ppt/slideMasters/_rels/slideMaster1.xml.rels PK k>]6TT!ppt/notesMasters/notesMaster1.xml 7/23/19Click to edit Master text stylesSecond levelThird levelFourth levelFifth level‹#›PK k>]s **,ppt/notesMasters/_rels/notesMaster1.xml.rels PK k>]_rels/PK k>] $docProps/PK k>]Kppt/PK k>] mppt/_rels/PK k>] ppt/charts/PK k>]ppt/charts/_rels/PK k>]ppt/embeddings/PK k>] ppt/media/PK k>]Bppt/slideLayouts/PK k>]qppt/slideLayouts/_rels/PK k>]ppt/slideMasters/PK k>]ppt/slideMasters/_rels/PK k>]  ppt/slides/PK k>]3ppt/slides/_rels/PK k>] bppt/theme/PK k>]ppt/notesMasters/PK k>]ppt/notesMasters/_rels/PK k>]ppt/notesSlides/PK k>]ppt/notesSlides/_rels/PK k>]"˩P[Content_Types].xmlPK k>]]] V_rels/.relsPK k>]!docProps/app.xmlPK k>]&O4(docProps/core.xmlPK k>]* * +ppt/_rels/presentation.xml.relsPK k>]Oݨ 6ppt/theme/theme1.xmlPK k>] Wppt/presentation.xmlPK k>]Xheppt/presProps.xmlPK k>]fppt/tableStyles.xmlPK k>]D >00gppt/viewProps.xmlPK k>]H7t!jppt/slideLayouts/slideLayout1.xmlPK k>]ђ77,mppt/slideLayouts/_rels/slideLayout1.xml.relsPK k>]}}koppt/slides/slide1.xmlPK k>]3 ppt/slides/_rels/slide1.xml.relsPK k>].'ppt/notesSlides/notesSlide1.xmlPK k>]:A*ppt/notesSlides/_rels/notesSlide1.xml.relsPK k>]uIIppt/slides/slide2.xmlPK k>]2- Kppt/slides/_rels/slide2.xml.relsPK k>]Wppt/notesSlides/notesSlide2.xmlPK k>]xշ*$ppt/notesSlides/_rels/notesSlide2.xml.relsPK k>]@@@7ppt/slides/slide3.xmlPK k>]W/ [.ppt/slides/_rels/slide3.xml.relsPK k>]K |Őg0ppt/notesSlides/notesSlide3.xmlPK k>]9 Y*47ppt/notesSlides/_rels/notesSlide3.xml.relsPK k>]'J:J:G9ppt/slides/slide4.xmlPK k>]` sppt/slides/_rels/slide4.xml.relsPK k>]vsuppt/notesSlides/notesSlide4.xmlPK k>]J *|ppt/notesSlides/_rels/notesSlide4.xml.relsPK k>]yDD~ppt/slides/slide5.xmlPK k>]5 ppt/slides/_rels/slide5.xml.relsPK k>]W8ppt/notesSlides/notesSlide5.xmlPK k>]Qe*kppt/notesSlides/_rels/notesSlide5.xml.relsPK k>]UfpMpM~ppt/slides/slide6.xmlPK k>]ج+ !ppt/slides/_rels/slide6.xml.relsPK k>]z-ppt/notesSlides/notesSlide6.xmlPK k>]=|*$ppt/notesSlides/_rels/notesSlide6.xml.relsPK k>]`gg 'ppt/slides/slide7.xmlPK k>]F >ppt/slides/_rels/slide7.xml.relsPK k>])lJppt/notesSlides/notesSlide7.xmlPK k>]|g*ppt/notesSlides/_rels/notesSlide7.xml.relsPK k>]-SS*ppt/slides/slide8.xmlPK k>]6 ppt/slides/_rels/slide8.xml.relsPK k>]iސppt/notesSlides/notesSlide8.xmlPK k>]pO*ppt/notesSlides/_rels/notesSlide8.xml.relsPK k>]߂r(W(Wppt/slides/slide9.xmlPK k>]>$ 4Pppt/slides/_rels/slide9.xml.relsPK k>]q@Rppt/notesSlides/notesSlide9.xmlPK k>]1* Yppt/notesSlides/_rels/notesSlide9.xml.relsPK k>]00 [ppt/slides/slide10.xmlPK k>]Ѳ!ppt/slides/_rels/slide10.xml.relsPK k>]O &ppt/notesSlides/notesSlide10.xmlPK k>]T+ppt/notesSlides/_rels/notesSlide10.xml.relsPK k>]KW<< ppt/slides/slide11.xmlPK k>];!'ppt/slides/_rels/slide11.xml.relsPK k>]s6ӑ 5ppt/notesSlides/notesSlide11.xmlPK k>]O+ppt/notesSlides/_rels/notesSlide11.xml.relsPK k>]M>WWppt/slides/slide12.xmlPK k>]c!ppt/slides/_rels/slide12.xml.relsPK k>]*)@ ppt/notesSlides/notesSlide12.xmlPK k>]Fb+ppt/notesSlides/_rels/notesSlide12.xml.relsPK k>]K !ppt/slideMasters/slideMaster1.xmlPK k>]N),lppt/slideMasters/_rels/slideMaster1.xml.relsPK k>]6TT!t!ppt/notesMasters/notesMaster1.xmlPK k>]s **,?ppt/notesMasters/_rels/notesMaster1.xml.relsPKSS{@