{"id":4069,"date":"2026-01-04T00:31:07","date_gmt":"2026-01-03T19:01:07","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=4069"},"modified":"2026-01-05T11:21:13","modified_gmt":"2026-01-05T05:51:13","slug":"plant-kingdom","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/plant-kingdom\/","title":{"rendered":"Plant Kingdom"},"content":{"rendered":"

The plant kingdom consists of\u00a0multicellular, eukaryotic organisms<\/strong>\u00a0that are autotrophic and contain chlorophyll. Plants are a diverse group that includes familiar organisms like trees, flowers, grasses, ferns, and mosses. There are over\u00a0300,000+ species<\/strong>\u00a0of plants that inhabit almost every environment on land.<\/p>\r\n

Plants play a critical role in ecosystems. As primary producers, they convert light energy from the sun into chemical energy through\u00a0photosynthesis<\/strong>. This energy then flows through the food chain, supporting almost all life on Earth either directly or indirectly. Plants also provide oxygen, stabilize soil, cycle nutrients, regulate climate, and offer habitat for animals.<\/p>\r\n

Evolution of Plant Kingdom Classification<\/h2>\r\n

Early classification systems divided plants based on growth forms into trees, shrubs and herbs. Subsequent systems incorporated internal structure and reproductive morphology.<\/p>\r\n

    \r\n\t
  • Systema Naturae: Carolus Linnaeus<\/strong>\u00a0introduced\u00a0the two-kingdom system\u00a0<\/strong>separating plants and animals (1735).<\/li>\r\n<\/ul>\r\n

    Plant Classification Systems<\/strong><\/h3>\r\n

    Botanists classify plants based on shared evolutionary history and characteristics. Classification helps understand relationships and origins.<\/p>\r\n

      \r\n\t
    • Linnaean classification:\u00a0<\/strong>The Linnaean system categorises plants using a hierarchy with kingdom, division, class, order, family, genus, and species, from broadest to most specific.\r\n\r\n
        \r\n\t
      • Taxonomic names consist of the genus and species Latinised name.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
      • Phylogenetic system:\u00a0<\/strong>It uses evolutionary relationships and DNA evidence to group plants.\r\n\r\n
          \r\n\t
        • Closely related plants share a common ancestor.<\/li>\r\n\t
        • Widely used phylogenetic groups include mosses, liverworts, ferns, gymnosperms, and angiosperms.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
        • Economic importance:<\/strong>\u00a0Food crops, ornamental plants, timber trees, medicinal plants, and fibre plants.<\/li>\r\n<\/ul>\r\n

          Classification of the Plant Kingdom<\/h2>\r\n

          Based on the above standards, the Plant Kingdom is divided into the following major lineages:<\/p>\r\n

          \"Classification<\/figure>\r\n

          Cryptogams Vs. Phanerogams<\/strong><\/h3>\r\n
          \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
          Cryptogams<\/strong><\/td>\r\nPhanerogams<\/strong><\/td>\r\n<\/tr>\r\n
          - These are\u00a0seedless plants\u00a0<\/strong>or\u00a0plant-like organisms.<\/strong><\/td>\r\n- These are referred to as\u00a0seed-bearing<\/strong>\u00a0plants.<\/td>\r\n<\/tr>\r\n
          - Sub-kingdom in the kingdom Plantae called\u00a0Cryptogamae.<\/strong><\/td>\r\n- Sub-kingdom in the kingdom Plantae called\u00a0Phanerogamae.<\/strong><\/td>\r\n<\/tr>\r\n
          \r\n

          - Reproduce using\u00a0spores.<\/strong><\/p>\r\n

            \r\n\t
          • Reproductive organs are Hidden.<\/li>\r\n<\/ul>\r\n<\/td>\r\n
          		\r\n

          - Reproduce using\u00a0seeds.<\/strong><\/p>\r\n

            \r\n\t
          • Reproductive organs are exposed.<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n
          - They are\u00a0less evolved<\/strong>\u00a0plants.<\/td>\r\n- They are\u00a0highly evolved\u00a0<\/strong>plants.<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

          Thallophyta (Algae)<\/strong><\/h3>\r\n

          Algae are\u00a0chlorophyll-bearing simple, thalloid, autotrophic\u00a0<\/strong>and\u00a0largely aquatic\u00a0<\/strong>organisms. They occur in freshwater, marine water, moist soils, rocks, etc.\u00a0Based on the type of photosynthetic pigments\u00a0<\/strong>possessed and the\u00a0type of storage<\/strong>\u00a0products, algae are classified into three major classes:<\/p>\r\n

          \r\n\r\n\r\n\r\n\r\n\r\n\r\n
          Class<\/strong><\/td>\r\nKey Features<\/strong><\/td>\r\nExamples<\/strong><\/td>\r\n<\/tr>\r\n
          Chlorophyceae\u00a0<\/strong>(green algae)<\/td>\r\n\r\n

          - Possess\u00a0chlorophyll a\u00a0<\/strong>and\u00a0b\u00a0<\/strong>pigments<\/p>\r\n

          - Store food as\u00a0starch<\/strong><\/p>\r\n

          - Cell wall made up of\u00a0cellulose<\/strong><\/p>\r\n

          -\u00a0Examples<\/strong>: Chlamydomonas, Volvox, Ulothrix, and, Spirogyra<\/p>\r\n<\/td>\r\n

          		\r\n

          - Volvox<\/p>\r\n

          \"Volvox\"<\/p>\r\n<\/td>\r\n<\/tr>\r\n

          Phaeophyceae\u00a0<\/strong>(brown algae)<\/td>\r\n\r\n

          - Possess\u00a0chlorophyll a, c, fucoxanthin<\/strong><\/p>\r\n

          - Store food as\u00a0laminarin\u00a0<\/strong>and\u00a0mannitol<\/strong><\/p>\r\n

          - Cell wall made of\u00a0cellulose\u00a0<\/strong>and\u00a0algin<\/strong><\/p>\r\n

          -\u00a0Examples<\/strong>: Ectocarpus, Dictyota, Laminaria, Sargassum, Fucus<\/p>\r\n<\/td>\r\n

          		\r\n

          - Ectocarpus<\/p>\r\n

          \"Ectocarpus\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
          Rhodophyceae\u00a0<\/strong>(red algae)<\/td>\r\n\r\n

          - Possess\u00a0chlorophyll a, d, phycoerythrin<\/strong><\/p>\r\n

          - Store food as\u00a0Floridian starch<\/strong><\/p>\r\n

          - Cell wall made of\u00a0cellulose\u00a0<\/strong>and\u00a0pectin<\/strong><\/p>\r\n

          -\u00a0Examples<\/strong>: Polysiphonia, Porphyra, Gracilaria, Gelidium<\/p>\r\n<\/td>\r\n

          		\r\n

          - Gracilaria<\/p>\r\n

          \"Gracilaria\"<\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

            \r\n\t
          • Reproduction in Thallophyta:<\/strong>\r\n
              \r\n\t
            • Vegetative Reproduction:<\/strong>\u00a0Algae reproduce vegetatively by fragmentation. Each fragment develops into a\u00a0new thallus<\/strong>.<\/li>\r\n\t
            • Asexual Reproduction:<\/strong>\u00a0It takes place by producing\u00a0zoospores<\/strong>\u00a0(motile) and\u00a0aplanospores<\/strong>\u00a0(non-motile).<\/li>\r\n\t
            • Sexual Reproduction: Isogamous<\/strong>\u00a0(fusion of morphologically similar gametes),\u00a0anisogamous\u00a0<\/strong>(fusion of morphologically dissimilar gametes) and\u00a0oogamous<\/strong>\u00a0(fusion of large, non-motile female gamete and small, motile male gamete).<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
            • Significance:<\/strong>\u00a0They are an important component of aquatic food chains.\r\n\r\n
                \r\n\t
              • Food:<\/strong>\u00a0Used as food (Porphyra, Laminaria),<\/li>\r\n\t
              • Industry:<\/strong>\u00a0Source of industrially important\u00a0hydrocolloids<\/strong>\u00a0(algin, carrageenan, agar).<\/li>\r\n\t
              • Biofertilizers:<\/strong>\u00a0Used as biofertilizers (Anabaena, Nostoc).<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                Bryophytes<\/strong><\/h3>\r\n

                Bryophytes include\u00a0liverworts<\/strong>\u00a0and\u00a0mosses<\/strong>\u00a0found commonly in\u00a0moist and shady habitats.\u00a0<\/strong>The plant body is thallus-like or differentiated into stem and leaf-like structures. The bryophytes possess root-like, leaf-like and stem-like structures. However, these lack true vascular tissues.\u00a0Important Characteristics:<\/strong><\/p>\r\n

                  \r\n\t
                • The plant body is a\u00a0gametophyte<\/strong>\u00a0that bears male and female sex organs (antheridia and archegonia).<\/li>\r\n\t
                • Sporophytes<\/strong>\u00a0are dependent on the gametophyte for nutrient supply.<\/li>\r\n\t
                • The dominant phase is gametophyte.<\/li>\r\n\t
                • Dependent on the water for reproduction.<\/li>\r\n\t
                • They lie in a transitional phase between\u00a0algae\u00a0<\/strong>and\u00a0pteridophytes.<\/strong><\/li>\r\n<\/ul>\r\n

                  Bryophytes are divided into:<\/strong><\/p>\r\n

                  \r\n\r\n\r\n\r\n\r\n\r\n
                  Class<\/strong><\/td>\r\nKey features<\/strong><\/td>\r\nExample<\/strong><\/td>\r\n<\/tr>\r\n
                  Liverworts<\/strong><\/td>\r\n\r\n

                  - The plant body is\u00a0dorsiventral\u00a0<\/strong>and\u00a0thallus<\/strong>-like<\/p>\r\n

                  -\u00a0Rhizoids<\/strong>\u00a0present on the ventral side for attachment<\/p>\r\n

                  -\u00a0Leaflike<\/strong>\u00a0structures present on the dorsal side<\/p>\r\n

                  - Example:<\/strong>\u00a0Marchantia<\/p>\r\n<\/td>\r\n

                  		\r\n

                  - Marchantia<\/p>\r\n

                  \"Marchantia\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                  Mosses<\/strong><\/td>\r\n\r\n

                  - The Plant body is\u00a0erect, slender, differentiated<\/strong>\u00a0into stems and leaves<\/p>\r\n

                  - Leaves arranged spirally around the stem<\/p>\r\n

                  - Attached to the substratum by multicellular branched rhizoids.<\/p>\r\n

                  - Example:<\/strong>\u00a0Funaria, Polytrichum, Sphagnum<\/p>\r\n<\/td>\r\n

                  		\r\n

                  - Funaria<\/p>\r\n

                  \"Funaria\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n
                  \"Liverwort\"<\/figure>\r\n
                  \"Life<\/figure>\r\n
                    \r\n\t
                  • Reproduction in Bryophytes:<\/strong>\r\n
                      \r\n\t
                    • Vegetative reproduction<\/strong>\u00a0by fragmentation, buds and gemmae.<\/li>\r\n\t
                    • Asexual reproduction<\/strong>\u00a0by spore formation. Haploid spores formed in sporangium undergo mitotic division to form\u00a0haploid protonema<\/strong>\u00a0or gametophyte.<\/li>\r\n\t
                    • Sexual reproduction<\/strong>\u00a0by formation of male and female gametes in\u00a0antheridia<\/strong>\u00a0and\u00a0archegonia.<\/strong>\r\n
                        \r\n\t
                      • Zygote<\/strong>\u00a0formed after fertilization divides mitotically to form diploid sporophyte.<\/li>\r\n\t
                      • Meiosis<\/strong>\u00a0in sporophytes produces haploid spores. Spores germinate to form gametophytes.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                      • Significance:<\/strong>\u00a0Used for packing material, production of antibiotics, and helps in soil conservation.<\/li>\r\n<\/ul>\r\n

                        Pteridophytes<\/strong><\/h3>\r\n

                        Pteridophytes are the\u00a0earliest terrestrial plants<\/strong>\u00a0with\u00a0well-developed\u00a0<\/strong>vascular tissues -\u00a0xylem\u00a0<\/strong>and\u00a0phloem<\/strong>. They occupy an intermediate position between bryophytes and higher plants.\u00a0Important characteristics:<\/strong><\/p>\r\n

                          \r\n\t
                        • The plant\u00a0body\u00a0<\/strong>is a sporophyte which is differentiated into true roots, stem and leaves.<\/li>\r\n\t
                        • Leaves\u00a0<\/strong>are small (microphylls) or large (microphylls).<\/li>\r\n\t
                        • Vascular tissues-<\/strong>\u00a0xylem and phloem are present.<\/li>\r\n\t
                        • Spores produced in\u00a0sporangia\u00a0<\/strong>are borne on sporophylls.<\/li>\r\n\t
                        • Sporophylls are arranged spirally to form\u00a0compact strobili<\/strong>\u00a0or cones.<\/li>\r\n\t
                        • Spores germinate to form gametophytes.<\/li>\r\n<\/ul>\r\n
                          \"Sequisetum\"<\/figure>\r\n

                          Pteridophytes are classified into:<\/strong><\/p>\r\n

                          \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
                          Class<\/strong><\/td>\r\nKey features<\/strong><\/td>\r\nExample<\/strong><\/td>\r\n<\/tr>\r\n
                          Psilopsida:<\/strong><\/td>\r\n\r\n

                          - Plant body is differentiated into stem, leaves and roots.<\/p>\r\n

                          -\u00a0Leaves:\u00a0<\/strong>Small, simple, entire, exstipulated.<\/p>\r\n

                          - Stem\u00a0dichotomously<\/strong>\u00a0branched.<\/p>\r\n

                          - Xylem lacks\u00a0tracheids<\/strong>, only vessels present<\/p>\r\n

                          - Example:<\/strong>\u00a0Psilotum<\/p>\r\n<\/td>\r\n

                          		\r\n

                          - Psilotum<\/p>\r\n

                          \"Psilotum\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                          Lycopsida:<\/strong><\/td>\r\n\r\n

                          - Includes club mosses and quillworts<\/p>\r\n

                          - Plant body creeping or erect<\/p>\r\n

                          - Leaves\u00a0microphyllous<\/strong>, small<\/p>\r\n

                          - Sporophylls aggregated to form\u00a0strobili<\/strong><\/p>\r\n

                          - Xylem with tracheids only<\/p>\r\n

                          - Example:<\/strong>\u00a0Selaginella, Lycopodium<\/p>\r\n<\/td>\r\n

                          		\r\n

                          - Selaginella<\/p>\r\n

                          \"Selaginella\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                          Sphenopsida:<\/strong><\/td>\r\n\r\n

                          - Stem is jointed with\u00a0whorled leaves<\/strong><\/p>\r\n

                          -\u00a0Leaves<\/strong>\u00a0are reduced to\u00a0toothed sheaths<\/strong>\u00a0at nodes<\/p>\r\n

                          - Stems are\u00a0photosynthetic<\/strong>\u00a0and channelled.<\/p>\r\n

                          - Xylem are with\u00a0tracheids\u00a0<\/strong>and\u00a0vessels<\/strong><\/p>\r\n

                          - Example:<\/strong>\u00a0Equisetum (Horsetails)<\/p>\r\n<\/td>\r\n

                          		\r\n

                          - Equisetum (Horsetails)<\/p>\r\n

                          \"Equisetum\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                          Pteropsida:<\/strong><\/td>\r\n\r\n

                          - Plant body is well differentiated<\/p>\r\n

                          -\u00a0Leaves\u00a0<\/strong>are\u00a0megaphyllous<\/strong>, large<\/p>\r\n

                          - Sporangia arranged in\u00a0sori\u00a0<\/strong>on leaves<\/p>\r\n

                          - Xylem contains\u00a0tracheids, vessels\u00a0<\/strong>and\u00a0phloem<\/strong><\/p>\r\n

                          - Example:<\/strong>\u00a0Dryopteris, Pteris, Adiantum (Ferns)<\/p>\r\n<\/td>\r\n

                          		\r\n

                          - Pteris<\/p>\r\n

                          \"pteris\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n
                            \r\n\t
                          • Reproduction in Pteridophytes:<\/strong>\r\n
                              \r\n\t
                            • Vegetative reproduction -<\/strong>\u00a0Fragmentation, budding<\/li>\r\n\t
                            • Asexual reproduction\u00a0<\/strong>- Spores formed by a\u00a0meiotic division\u00a0<\/strong>in sporangia<\/li>\r\n\t
                            • Sexual reproduction<\/strong>\u00a0- Male and female gametes (antherozoids and eggs) formed in\u00a0antheridia\u00a0<\/strong>and\u00a0archegonia<\/strong>\u00a0on gametophytes. Zygote forms sporophyte after fertilization.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                            • Significance:<\/strong>\u00a0Used as medicines, bio-fertilisers, soil binders, and ornamental plants.<\/li>\r\n<\/ul>\r\n
                              \"Fern<\/figure>\r\n

                              Gymnosperms<\/strong><\/h3>\r\n

                              Gymnosperms are\u00a0seed-bearing plants\u00a0<\/strong>in which ovules are not enclosed by any ovary wall or fruit; hence the seeds remain exposed or naked.<\/p>\r\n

                              Important characteristics are:<\/p>\r\n

                                \r\n\t
                              • Heterosporous<\/strong>\u00a0- Produces microspores and megaspores.<\/li>\r\n\t
                              • Wind pollinated.<\/li>\r\n\t
                              • Vascular tissues are present.<\/li>\r\n\t
                              • Perennial, evergreen<\/strong>\u00a0trees or shrubs.<\/li>\r\n<\/ul>\r\n
                                \"Ginkgo\"<\/figure>\r\n
                                \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
                                Class<\/strong><\/td>\r\nKey features<\/strong><\/td>\r\nExample<\/strong><\/td>\r\n<\/tr>\r\n
                                Cycadales<\/strong><\/td>\r\n\r\n

                                - Plants are\u00a0palm-like, tropical<\/strong><\/p>\r\n

                                -\u00a0Stem\u00a0<\/strong>is unbranched, woody, covered with persistent leaf bases<\/p>\r\n

                                -\u00a0Leaves\u00a0<\/strong>are\u00a0large, pinnate, circinate vernation<\/strong><\/p>\r\n

                                -\u00a0Roots\u00a0<\/strong>are coralloid with\u00a0symbiotic cyanobacteria<\/strong><\/p>\r\n

                                - Seeds are naked and produced on modified leaf margins.<\/p>\r\n

                                - Example:<\/strong>\u00a0Cycas, Zamia<\/p>\r\n<\/td>\r\n

                                		\r\n

                                \u00a0- Cycas<\/p>\r\n

                                \"Cycas\"<\/p>\r\n<\/td>\r\n<\/tr>\r\n

                                Coniferales<\/strong><\/td>\r\n\r\n

                                - Mainly evergreen trees with a needle or scale-like leaves<\/p>\r\n

                                -\u00a0Cones or strobili<\/strong>\u00a0for reproduction<\/p>\r\n

                                - Wood with\u00a0resin ducts<\/strong><\/p>\r\n

                                - Leaves often with thick\u00a0cuticles<\/strong>\u00a0and\u00a0sunken stomata<\/strong><\/p>\r\n

                                - Pollen are dispersed by wind (anemophilous)<\/p>\r\n

                                - Example:<\/strong>\u00a0Pinus, Cedrus (cedar), Abies (fir)<\/p>\r\n<\/td>\r\n

                                		\r\n

                                - Pinus<\/p>\r\n

                                \"Pinus\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                                Ginkgoales<\/strong><\/td>\r\n\r\n

                                -Only one living species -\u00a0Ginkgo biloba<\/strong><\/p>\r\n

                                - Leaves broad, bilobed with open dichotomous venation<\/p>\r\n

                                - Long shoots bear leaves; short shoots bear cones<\/p>\r\n

                                -\u00a0Motile male gametes\u00a0<\/strong>require water for the transfer<\/p>\r\n

                                - Seeds with foul-smelling outer fleshy layer<\/p>\r\n

                                - Example:<\/strong>\u00a0Ginkgo, Maidenhair tree<\/p>\r\n<\/td>\r\n

                                		\r\n

                                - Ginkgo<\/p>\r\n

                                \"Ginkgo\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                                Gnetales<\/strong><\/td>\r\n\r\n

                                - They are\u00a0Xerophytic shrubs<\/strong>\u00a0and trees.<\/p>\r\n

                                - Leaves are simple, with scales and needles.<\/p>\r\n

                                - Cones are unisexual with reduced\u00a0perianth.<\/strong><\/p>\r\n

                                - Vessels are absent in the\u00a0xylem.<\/strong><\/p>\r\n

                                - Seeds are large without\u00a0endosperm<\/strong><\/p>\r\n

                                - Example:<\/strong>\u00a0Ephedra, Gnetum, Welwitschia<\/p>\r\n<\/td>\r\n

                                		\r\n

                                - Ephedra<\/p>\r\n

                                \"Ephedra\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n
                                  \r\n\t
                                • Reproduction in Gymnosperms:<\/strong>\r\n
                                    \r\n\t
                                  • Vegetative reproduction:\u00a0<\/strong>Coralloid roots in Cycas.<\/li>\r\n\t
                                  • Asexual reproduction<\/strong>: Cones or strobili-bearing microsporophylls produce\u00a0microspores\u00a0<\/strong>and strobili-bearing megasporophylls produce\u00a0megaspores.<\/strong><\/li>\r\n\t
                                  • Sexual reproduction<\/strong>: Microspores develop into male gametophytes containing\u00a0antheridia\u00a0<\/strong>(pollen grains).\r\n\r\n
                                      \r\n\t
                                    • Megaspores develop into female gametophytes containing\u00a0archegonia<\/strong>. Pollen grains are carried to the ovule by the wind.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                    • The pollen tube releases male gamete into the ovule where it fuses with an egg in the\u00a0archegonium<\/strong>. The zygote develops into an embryo and ovules into seeds.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                    • Significance:<\/strong>\u00a0Wood, resin, turpentine oil, paper pulp, ornamental plants<\/li>\r\n<\/ul>\r\n

                                      Angiosperms<\/strong><\/h3>\r\n

                                      Angiosperms or flowering plants possess reproductive organs protected by\u00a0floral envelopes or perianth.<\/strong>\u00a0Pollen grains and ovules develop inside specialized structures of the flower. After fertilisation, seeds develop inside ovaries which ripen into fruits.<\/p>\r\n

                                      Important Characteristics are:<\/p>\r\n

                                        \r\n\t
                                      • Flowers are enclosed by\u00a0floral envelopes.<\/strong><\/li>\r\n\t
                                      • Seeds are enclosed in fruits.<\/li>\r\n\t
                                      • Pollen grains and ovules are produced in specialized structures of flowers.<\/li>\r\n\t
                                      • Vascular tissues are present.<\/li>\r\n<\/ul>\r\n

                                        Angiosperms are divided into two classes:<\/p>\r\n

                                        \r\n\r\n\r\n\r\n\r\n\r\n
                                        Class<\/strong><\/td>\r\nKey features<\/strong><\/td>\r\nExample<\/strong><\/td>\r\n<\/tr>\r\n
                                        Dicotyledons<\/strong><\/td>\r\n\r\n

                                        - Tap root system<\/p>\r\n

                                        -\u00a0Reticulate venation\u00a0<\/strong>(vein pattern classifications) in leaves.<\/p>\r\n

                                        - Flower parts in 4 or 5 or multiples of 4 or 5<\/p>\r\n

                                        -\u00a0Two cotyledons<\/strong>\u00a0in seed<\/p>\r\n

                                        - Vascular bundles in a ring arrangement<\/p>\r\n

                                        - Examples:<\/strong>\u00a0Rose, potato, tobacco, pea<\/p>\r\n<\/td>\r\n

                                        		\r\n

                                        - Rosaceae<\/p>\r\n

                                        \"Rosaceae\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n
                                        Monocotyledons<\/strong><\/td>\r\n\r\n

                                        - Fibrous root system<\/p>\r\n

                                        -Parallel venation<\/p>\r\n

                                        - Flower parts in 3 or multiples of 3<\/p>\r\n

                                        -\u00a0One cotyledon<\/strong>\u00a0in seed<\/p>\r\n

                                        - Scattered vascular bundles<\/p>\r\n

                                        - Examples:<\/strong>\u00a0Lily, wheat, rice<\/p>\r\n<\/td>\r\n

                                        		\r\n

                                        - Liliaceae<\/p>\r\n

                                        \"Lliaceae\"<\/figure>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n
                                          \r\n\t
                                        • Reproduction in Angiosperms:<\/strong>\r\n
                                            \r\n\t
                                          • Vegetative reproduction<\/strong>\u00a0- Cuttings, grafting.<\/li>\r\n\t
                                          • Asexual reproduction<\/strong>\u00a0\u2013 Production of seeds without fusion of gametes (apomixis).<\/li>\r\n\t
                                          • Sexual reproduction -\u00a0<\/strong>Flower contains\u00a0stamens<\/strong>\u00a0(microsporophyll) and\u00a0carpels\u00a0<\/strong>(megasporophyll). Microspores in\u00a0anther sacs\u00a0<\/strong>divide mitotically to form pollen grains containing male gametophyte.<\/li>\r\n\t
                                          • Megaspore<\/strong>\u00a0in the ovule divides\u00a0mitotically\u00a0<\/strong>to form an embryo sac (female gametophyte) containing egg cells.\r\n\r\n
                                              \r\n\t
                                            • Pollen grains are transferred to stigma by agents like wind, water, animals etc.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                            • The pollen tube grows through style and releases\u00a0two male gametes<\/strong>\u00a0into the ovule\u2014one fuse with an egg cell forming a zygote.<\/li>\r\n\t
                                            • The zygote develops into an embryo and ovules into seeds. Ovary matures into fruit.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                            • Significance:<\/strong>\u00a0Provide food, fuel, medicine, timber, fibres, oils, dyes, gums, resins etc.<\/li>\r\n<\/ul>\r\n
                                              \"Plant<\/figure>\r\n

                                              Plant Structure and Function<\/h2>\r\n

                                              While plants exhibit a variety of forms, they share key structural and functional elements.<\/p>\r\n

                                                \r\n\t
                                              • Roots:\u00a0<\/strong>Roots anchor the plant and absorb water and minerals from the soil.\r\n\r\n
                                                  \r\n\t
                                                • Root systems can be fibrous or taproots.<\/li>\r\n\t
                                                • Specialised roots may store food or enable vegetative reproduction.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                • Stems:\u00a0<\/strong>Stems provide structural support and allow vascular transport.\r\n\r\n
                                                    \r\n\t
                                                  • Herbaceous plants\u00a0<\/strong>have soft, green stems while woody plants develop hardy stems covered by bark.<\/li>\r\n\t
                                                  • Modified stems include\u00a0rhizomes, corms, tubers,\u00a0<\/strong>and\u00a0bulbs.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                  • Leaves:\u00a0<\/strong>Leaves are the primary site of\u00a0photosynthesis.\r\n\r\n
                                                      \r\n\t
                                                    • Flat, expanded leaves maximise light capture.<\/li>\r\n\t
                                                    • Leaf anatomy includes\u00a0epidermal cells, stomata, xylem,\u00a0<\/strong>and\u00a0phloem<\/strong>\u00a0within a vascular bundle.<\/li>\r\n\t
                                                    • Leaf arrangements, shapes, and margins vary widely.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n
                                                      \"Leaf<\/figure>\r\n
                                                        \r\n\t
                                                      • Reproductive Structures:\u00a0<\/strong>Plants reproduce sexually via spores and seeds and asexually via vegetative propagation.\u00a0<\/strong>\r\n
                                                          \r\n\t
                                                        • Flowers contain male and female reproductive organs.<\/li>\r\n\t
                                                        • After fertilisation, flowers develop into fruits containing seeds.<\/li>\r\n\t
                                                        • Cones, spores,\u00a0<\/strong>and\u00a0sporangia\u00a0<\/strong>facilitate reproduction in non-flowering plants.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                        • Vascular Tissue:\u00a0<\/strong>The xylem transports water and minerals absorbed by the roots upwards through the plant.\r\n\r\n
                                                            \r\n\t
                                                          • Phloem<\/strong>\u00a0transports\u00a0sugars\u00a0<\/strong>produced by photosynthesis throughout the plant.<\/li>\r\n\t
                                                          • Together, the\u00a0xylem\u00a0<\/strong>and\u00a0phloem<\/strong>\u00a0form the\u00a0vascular system<\/strong>\u00a0that facilitates growth and structural support.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                          • Meristems:\u00a0<\/strong>Meristems are tissues of undifferentiated, rapidly dividing cells that enable plant growth.\r\n\r\n
                                                              \r\n\t
                                                            • Apical meristems<\/strong>\u00a0facilitate primary growth at the\u00a0shoot\u00a0<\/strong>and\u00a0root tips<\/strong>.<\/li>\r\n\t
                                                            • Lateral meristems\u00a0<\/strong>facilitate secondary growth and increase\u00a0stem\u00a0<\/strong>and\u00a0root diameter.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                            • Photosynthesis:\u00a0<\/strong>Photosynthesis converts light energy from the sun into chemical energy stored in glucose molecules.\r\n\r\n
                                                                \r\n\t
                                                              • Chloroplasts\u00a0<\/strong>in leaf\u00a0mesophyll cells<\/strong>\u00a0carry out photosynthesis using chlorophyll pigments, generating oxygen as a byproduct.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>","protected":false},"excerpt":{"rendered":"

                                                                An overview of the plant kingdom including classification, characteristics of major divisions and examples of plant species from each group.<\/p>\n","protected":false},"author":6,"featured_media":7959,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[173],"tags":[529,40],"class_list":{"0":"post-4069","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quest-level-3","8":"tag-plant-kingdom","9":"tag-quest"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4069","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=4069"}],"version-history":[{"count":1,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4069\/revisions"}],"predecessor-version":[{"id":19981,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/4069\/revisions\/19981"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/7959"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=4069"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=4069"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=4069"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}