Kingdom Plantae PDF

3. Kingdom Plantae Can you recall? Observe and Discuss 1. Why do we call plants as producers on...

3. Kingdom Plantae Can you recall? Observe and Discuss 1. Why do we call plants as producers on Collect different water samples of land ? fresh water. Mount them on a glass slide and 2. What are differences between observe under a compound microscope. Try sub-kingdoms Cryptogamae and to identify the organisms which are visible Phanerogamae? under it. 3. Differentiate between Thallophytes and Bryophytes. 3.2 Salient features of major plant 4. Give any two examples of Pteridophyta. groups under Cryptogamae : 3.1 Kingdom plantae : A. Division : Thallophyta - Members In earlier chapter, we have studied are mostly aquatic, few grow on other plants different aspects of classification. as epiphytes. Some grow symbiotically and Kingdom Plantae is further classified epizoic i.e. growing or living non-parasitically on the basis of characteristics like absence on the exterior of living organisms. Aquatic or presence of seeds, vascular tissues, algae grow in marine or fresh water. Most of differentiation of plant body, etc. them are free living while some are symbiotic. Phanerogamae are commonly called seed Plant body is thalloid i.e. undifferentiated producing plants. They produce special into root, stem and leaves. They may be small, reproductive structures that are visible unicellular, microscopic like Chlorella (non- (Phaneros – visible) motile), Chlamydomonas (motile). They can Cryptogamae are spore producing plants be multicellular, unbranched, filamentous like and do not produce seeds and flowers. Spirogyra or branched, filamentous like Chara. They reproduce sexually by gametes but Sargassum, a huge macroscopic sea weed sex organs are concealed (kryptos : hidden, which measures more than 60 meters in length gamos : marriage). is also an alga. Classification of Kingdom Plantae is represented as follows : Kingdom- Plantae Cryptogamae Phanerogamae Non-Vascular Plants Vascular Plants Vascular Plants Thallophyta Bryophyta Pteridophyta Gymnospermae Angiospermae Algae Dicotyledonae Monocotyledonae Chart 3.1 Classification of Kingdom Plantae 19  The algal cell wall contains either Pyrenoids are located on Chloroplast. polysacchrides like cellulose / glucose or Members are rich in protein, so used as food; a veriety of proteins or both. Reserve food used even by space travellers. e.g. Chlorella. is in the form of starch and its other forms. Chlamydomonas, Spirogyra, Chara, Volvox, Reproduction takes place by vegetative, Ulothrix etc. asexual and sexual ways. The life cycle shows phenomenon of alternation of generation, Internet my friend dominant haploid and reduced diploid phases. Algae are classified as per its pigments like 1. Make a list of green algae with their chlorophyll, xanthophylls and phycobilin. characteristic shape of chloroplast. 2. Enlist the forms of filamentous algae. a. Chlorophyceae (green algae) : 3. Write different pigments found algae. These are mostly fresh water (few brackish water and marine) forms. b. Phaeophyceae (Brown algae) : Plant body is unicellular, colonial, filamentous. Plant body : Mostly marine, rarely Cell wall contains cellulose. fresh water. Simple branched / filamentous (e.g. Chloroplasts are of various shapes Ectocarpus) / profusely branched (Petalonia). like discoid, plate-like, reticulate, cup-shaped, Cell wall has cellulose, fucans ribbon-shaped or spiral with chlorophyll a and and algin. Photosynthetic pigments like b. The stored food is in the form of true starch. chlorophyll-a, -c and fucoxanthin are present. Mannitol, laminarin and starch are the stored Chloroplast food materials. Body is usually differentiated Nucleus into holdfast, stalk called stipe and leaf-like Chlamydomonas photosynthetic organ called frond. Many species of marine algae are used as food. Pyrenoid (starch storage) e.g. Laminaria, Sargassum. Some species are used for production of hydrocolloids. e.g. Mitochondria (Amino acid synthesis) Ectocarpus, Fucus, etc. Oogonium Frond (contains eggs) (Lamina) Chara Antheridium Stipe (contains sperm) Gametophyte Holdfast Mucilage Cell membrane Sargassum Cell wall Cytoplasm Laminaria Spirogyra Cytoplasm Nucleus Pyrenoid Fucus strand Chloroplast Vacuole Fig. 3.2 Chlorophyceae Fig. 3.3 Phaeophyceae 20 c. Rhodophyceae (Red algae) : Plant body These are found in marine Can you tell? as well as fresh water on the surface, deep sea 1. What are the three major groups of and brakish water. Plant body is thalloid. Cells Cryptogams ? contain chlorophyll a, d and phycoerythrin. 2. Name the accessory pigments of algae. Cell wall is made up of cellulose and pectin 3. Give salient features of algae glued with other carbohydrates. Stored food is 4. Differentiate between Chlorophyceae and in the form of Floridean starch. Commercially Phaeophyceae. important agar-agar which is used as 5. Enlist examples of Chlorophyceae and solidifying agent in tissue culture medium, Rhodophyceae. is obtained from red algae. e.g. Chondrus, Batrachospermum Porphyra, Gelidium , Observe and Discuss Gracillaria, Polysiphonia, etc. You may have seen Funaria plant in rainy season. Why is it called amphibious plant? Batrachospermum B. Bryophyta (Bryon : moss ; phyton : plant) Bryophytes are mostly terrestrial plants. They are found in moist shady places. But they need badly water for fertilization and completion of their life cycle. Hence they Gracillaria are called ‘amphibious plants’. They include approximately 960 genera and about 25,000 species. Life cycle of Bryophytes shows sporophytic and gametophytic stages. Vegetative plant body is thalloid or leafy which represents gametophytic generation. Spore Polysiphonia producing capsule represents sporophytic generation. Bryophytes have root-like structures called rhizoids. Rhizoids are unicellular in liverworts while multicellular in mosses. Fig. 3.4 Rhodophyceae Rhizoids absorb water and minerals and also Internet my friend help in fixation of thallus on the substratum. 1. Economic importance of algae. Bryophytes are divided into two groups : 2. Role of algae in environment. liverworts and mosses. 3. Different forms of green, red, brown and a. Liverworts (Hepaticeae) : blue green algae. These are lower members of Bryophyta. These are primitive group of Bryophytes. Gametophyte possesses flat plant body called Do you know ? thallus. The thallus is green, dorsiventral, Brown algae- kelps may grow up prostrate with unicellular rhizoids. e.g. Riccia, to 100 meters in height. Find out more Marchantia. information about Sargasso sea. 21 Hornworts (Anthocerotae) - These member Economic importance - possess flattened thallus. The thallus produces Some mosses provide food for horny structures which are called sporophytes herbivorous mammals, birds, etc. Species of hence the name hornworts. e.g. Anthoceros. Sphagnum, a moss; provides peat used as fuel. b. Mosses (Musci) : Mosses are also used as packing material for These are advanced members of transport of living materials because they Bryophyta which possess erect plant body. have significant water holding capacity. Just Gametophytic phase of the life cycle like lichens, mosses are the first living beings includes two stages namely; protonema stage to grow on rocks. They decompose rocks to and leafy stage. The protonema is prostrate form soil and make them suitable for growth green, branched and filamentous (it is also of higher plants. Dense mats of mosses help called juvenile gametophyte). It bears many in prevention of soil erosion, thus act as soil buds. Leafy stage is produced from each binders. bud. Thus protonema helps in the vegetative C. Pteridophyta propagation. The leafy stage has erect, slender (Pteron : feather, phyton : plant) stem like (Cauloid) main axis bearing spirally Evolutionarily, Pteridophytes are the arranged leaf like structures (Phylloid). It is first vascular and true land plants. Hence fixed in soil by multicellular branched rhizoids. considered as the first successful terrestrial This stage bears sex organs. Vegetative plants with true roots, stem and leaves. These reproduction takes place by fragmentation and plants have a primitive conducting system and budding in secondary protonema. they are the only Cryptogams with vascular e.g. Funaria, Polytrichum, Sphagnum, etc. tissues. The late Paleozoic era is regarded as the age of Pteridophytes. The group has about 400 genera and 11,000 species. The plants consist of pinnate (feather like) leaves. Leaves may be small called microphylls (e.g. Selaginella) or large called macrophylls (e.g. Nephrolepis / fern). Blade Riccia (Liverworts) Anthoceros Frond Capsule Sporophyte Seta Rhizome foot Roots Back side Front side Gametophyte Main axis Funaria Rhizoids Fig. 3.5 Mosses Fig. 3.6 Nephrolepis (Fern) 22  Observe and Discuss Observe and Discuss You may have seen the various plants Observe all garden plants like Cycas, which do not bear flowers, fruits and seeds Thuja, Pinus, Sunflower, Canna and compare but they have well developed root, stem and them. Note similarities and dissimilarities leaves. Discuss. among them. Which differences did you notice between Gymnosperms and Angiosperms? Pteridophytes grow in moist and shady places. Pteridophytes show sporophytic and 3.3 Salient features of major plant groups gametophytic stages in life cycle. e.g. Ferns, under Phanerogamae: Horsetail. Some are aquatic (Azolla, Marsilea), A. Gymnospermae xerophytic (Equisetum) and epiphytic (Gymnos : naked, sperma : seed) :- (Lycopodium). There are about 70 genera and 1000 Pteriodphytes show heteromorphic living species of Gymnosperms in world. In alternation of generations in which the India group is represented by 16 genera and 53 sporophyte is diploid, dominant, autotrophic species. and independent. It is differentiated into root, stem and leaves. The primary root is short lived Foliage leaves and soon replaced by adventitious roots while the stem may be aerial or underground. Leaves may be scaly (Equisetum), simple and sessile (Lycopodium) or large and pinnately compound (Nephrolepis / Ferns). In these members, xylem consists of b. Corraloid roots only tracheids and Phloem consists of only of Cycas sieve cells. Secondary growth is not seen in Pteridophytes due to absence of cambium. Pteridophytes are classified as - Stem Psilopsida- (Psilotum), Lycopsida - (Selaginella a. Cycas plant body and Lycopodium), Sphenopsida - (Equiesetum) and Pteropsida - (Dryopteris, Pteris and Algal zone Adiantum) c. T. S. of Coralloid root of Cycas Economic importance - Pteridophytes are Used for medicinal purpose and as soil binders. Many varieties are grown as ornamental plants. Can you tell? 1. Distinguish between Bryophyta and Pteridophyta. d. Male cone of Cycas 2. Why Bryophyta are called amphibians of having Plant Kingdom? microsporophylls 3. Pteridophytes are also known as vascular Cryptogams - Justify. e. Megasporophyll of Cycas 4. Give one example of aquatic and xerophytic Pteridophytes. Fig. 3.7 Cycas plant details 23  Most of the Gymnosperms are evergreen, shrubs or woody trees. These are primitive Do you know ? group of flowering plants producing naked Gymnosperms like Ginkgo biloba is seeds. They are vascular plants predominantly called living fossil. It is because the plant is having Xylem with tracheids and Phloem with found in living as well as fossil form and the sieve cells. number of fossil forms is much more than the The plant body is sporophyte. It is living forms. differentiated into root, stem and leaves. The Gymnosperms vary in their size. e.g. root system is tap root type. In some, roots form Sequoia sempervirens is the tallest living plant symbiotic association with other life forms. in the world. It is commonly called coast red Coralloid roots of Cycas, show association wood of California. The height of the plant is with blue green algae and roots of Pinus about 366 feet. Taxodium mucronatum has a show association with endophytic fungi called girth of about 125 feet. Zamia pygmaea is the mycorrhizae. smallest Gymnosperms and is about 25 cms. In Gymnosperms, stem is mostly erect, only. aerial, solid and cylindrical. Secondary growth is seen in Gymnosperms due to presence of cambium. In Cycas it is usually unbranched, Try this while in conifers it is branched. The leaves are Study the leaves of Hibiscus, Peepal, dimorphic. The foliage leaves are green, simple Canna, Grass and Tulsi. Classify them as needle like or pinnately compound, where as Monocot and Dicot. scale leaves are small, membranous and brown. Spores are produced by microsporophyll (Male) and megasporophyll (Female). Can you recall? Economic importance - Cycas is grown as 1. What are the salient features of ornamental plant. Pinus is used as source of Angiospermae? pine wood, turpentine oil and pine resin. 2. What is double fertilization ? 3. Explain in brief two classes of Angiospermae? Draw and label one example of each class. B. Angiospermae (Angios : enclosed : vessel, Sperma : seed) Angiosperms are the most advanced group of flowering plants. In these plants the seeds are enclosed within the fruit i.e. ovary. Angiosperms is a group of highly evolved plants, primarily adapted to terrestrial habitat. They vary in size. Angiosperms show heteromorphic alternation of generation in which the sporophyte is diploid, dominant, autotrophic and independent. The gametophytes (male or Fig. 3.8 Pinus tree with cones female) are haploid, reduced, parasitic and concealed in the sporophyte. 24  Angiosperms are heterosporous. a. Monocotyledonae : These plants have Microspores (commonly called pollens) are single cotyledon in their embryo. They have formed in microsporangia (of anthers). They adventitious root system and stem is rarely develop in highly specialized microsporophylls branched. Leaves generally have sheathing leaf or stamens while megaspores are formed in base and parallel venation while the flowers megasporangia (or ovules) borne on highly are generally trimerous. specialized megasporophyll called carpel. The vascular bundles are conjoint, Besides the essential whorls of collateral and closed type. In Monocots, except microsporophylls (Androecium) and few plants secondary growth is absent. e.g. Zea megasporophylls (Gynoecium), there are mays (Maize), Sorghum vulgare (Jowar). accessory whorls namely calyx (sepals) and corolla (petals) arranged together to form Corn grain Tassel flowers. Silks Leaf blade Do you know ? Wolffia is the smallest Angiosperm, 1mm in size and Eucalyptus grows to over 100 meters high. Ear Angiosperms are subdivided into two classes: Roots a. Dicotyledonae : These plants have two Fig. 3.10 Zea mays (Maize) cotyledons in their embryo. They have a tap root system and the stem is branched. Leaves Can you tell? show reticulate venation while the flowers show tetra- or pentamerous symmetry. 1. Give general chara cters of Gymnosper- Vascular bundles are conjoint, collateral mae and Angiospermae. and open type. Cambium is present between 2. Distinguish between Dicotyledonae and Xylem and Phloem for secondary growth. In Monocotyledonae. Dicots, secondary growth is commonly found. 3. Why do Dicots show secondary growth e.g. Helianthus annuus (sunflower), Hibiscus while Monocots don't? rosa-sinensis (China rose). 3.4 Plant life cycle and alternation of Seeds generations: Life cycle of a plant includes two phases or distinct generations namely sporophyte Ray florets (diploid : 2n) and gametophyte (haploid : n). Disc florets Some special diploid cells of sporophyte divide by meiosis to produce haploid cells. These haploid cells divide mitotically to give rise Stem to gametophyte. The gametophyte produces separately male and female gametes which fuse Tap root during fertilization to produce diploid zygote. It divides by mitosis to form diploid sporophyte. Inflorescence The sporophytic and gametophytic generations of Sunflower generally occur alternately in the life cycle of Fig. 3.9 Helianthus annuus (Sunflower) a plant. This phenomenon is called alternation of generations. 25  Distinct alternation of these two Sporophyte (2n) generations is observed in Bryophytes and Pteridophytes. In Gymnosperms and Angiosperms, gametophyte is much reduced Zygote and exists within sporophyte. In algae, based (2n) Sporophyte upon the nature of dominant phase in life Fertilization phase cycle, it is called haplontic, diplontic or haplo- Meiosis Gametophyte diplontic life cycle. phase Spores Gametes (1n) In Bryophytes haploid gametophyte (1n) is dominant. It is photosynthetic, independent thalloid or erect phase. Sporophyte is short lived, multicellular and depends totally or partially Gametophyte (1n) on gametophyte for nutrition and anchorage. Fig. 3.11 Alternation of generation Whereas in Pteridophytes, sporophyte is dominant, independent and vascular plant body. Haploid multicellular independent, non Can you tell? vascular gametophyte is generally autotrophic 1. What is alternation of generations? and short lived. It alternates with Sporophyte. 2. Which phase is dominant in the life cycle of Bryophyta and Pteridophyta ? Diplontic Haplontic Haplo-Diplontic Haploid single-cell or Haploid multicellular multicellular organism organism Gametes Mitosis n Mitosis Mitosis Mitosis es Gametes es or or Fertilization Meiosis Sp Sp Fertilization Meiosis Fertilization Meiosis 2n Diploid Diploid Mitosis Plants and multicellular Fungi and multicellular some algae some algae organism In animals organism Fig. 3.12 Types of life cycle Diplontic : Haplontic : Haplo-diplontic : Here mitotic Here mitosis occurs Here mitosis divisions occurs only in in haploid cells. It results in the occur in both diploid diploid cells. Gametes formation of single haploid cells or and haploid cells. These formed through meiosis are a multicellular haploid organism. organisms undergo through haploid in nature. The diploid These forms produce the gametes a phase in which they are zygote divide mitotically. through mitosis. Zygote is formed multicellular and haploid In this process production after fertilization. This cell is the (the gametophyte), and a of multicellular diploid only diploid cell in the entire life phase in which they are organism or in the production cycle of the organism. Thus the same multicellular and diploid of many diploid single cells zygotic cell later undergoes meiosis. (the sporophyte). E.g. Land takes place. E.g. Animals. E.g. Some Algae and Fungi. plants and in many algae. 26  Exercise 1. Choose correct option 4. Differentiate between Dicotyledonae and A. Which is the dominant phase in Pteri- Monocotyledonae based on the following dophytes? characters a. Capsule b. Gametophyte a. Type of roots c. Sporophyte d. Embryo b. Venation in the leaves B. The tallest living gymnosperm among c. Symmetry of flower the following is.......... 5. Answer the following questions a. Sequoia sempervirens A. We observe that land becomes barren b. Taxodium mucronatum soon after monsoon. But in the next c. Zamia pygmaea monsoon it flourishes again with d. Ginkgo biloba varieties we observed in season earlier. C. In Bryophytes.......... How you think it takes place? a. Sporophyte and gametophyte B. Fern is a vascular plant. Yet it is not generations are independent considered a Phanerogams. Why? b. Sporophyte is partially dependent C. Chlamydomonas is microscopic whereas upon gametophyte Sargassum is macroscopic, both are c. Gametophyte is dependent upon algae. Which characters of these plants Sporophyte includes them in one group? d. Inconspicuous gametophyte is present 6. Girth of a Maize plant does not increase over a period of time. Justify D. A characteristic of Angiosperm is......... a. Collateral vascular bundles 7. Radha observed a plant in rainy season b. Radial vascular bundles on the compound wall of her school. The c. Seed formation plant did not have true roots but rootlike d. Double fertilization structures were present. To which group the plant may belong? E. Angiosperms differ from Gymnosperms in having.......... 8. Draw neat labelled diagrams a. Vessels in wood A. Spirogyra b. Autotrophic Mode of nutrition B. Chlamydomonas c. Siphonogamy C. Funaria d. Enclosed seed D. Nephrolepis 2. How you place the pea, jawar and fern E. Haplontic and haplodiplontic life cycle at its proper systematic position? Draw a flow chart of each. 3. Complete the following table Groups of algae Chlorophyceae Phaeophyceae Rhodophyceae 1. Stored food Starch 2. Cell Wall Cellulose and algin 3. Major pigments Chl- a, d and Phycoerythrin 27 9. Identify the plant groups on the basis of 10. Observe the following diagram. Correct following features. it and write the information in your A. Seed producing plants words. B. Spore producing plants Sporophyte (2n) C. Plant body undifferenciated into Root, Gametes Stem and leaves (1n) D. Plant need water for fertilization E. First vascular plants Gametophyte Meiosis phase Practical / Project : Fertilization Sporophyte 1. Study the Nephrolepis plant in detail. phase 2. Study the coralloid roots, scale leaf Zygote (2n) and megasporophyll of Cycas in detail. Spores (1n) 28