Kingdom Plantae PDF

Mithibai College Biology KINGDOM PLANTAE F.Y.J.C BIOLOGY Kingdom Plantae is broadly classified into two sub kingdoms, Cryptogamae and Phanerogamae...

Mithibai College Biology KINGDOM PLANTAE F.Y.J.C BIOLOGY Kingdom Plantae is broadly classified into two sub kingdoms, Cryptogamae and Phanerogamae Cryptogamae Phanerogamae 1. Do not produce seeds & flowers 1. Seeds and flowers are produced. 2. Sex organs are concealed 2. Sex organs are visible 3. It includes three major groups: Algae, 3. It includes two groups: Gymnosperms Bryophyta, Pteridophyta and Angiosperms 4. Except Pteridophytes, all are non-vascular 4. All are vascular plants ALGAE - GENERAL CHARACTERISTICS Mostly aquatic, few terrestrial Free living or symbiotic, few may be epiphytes or epizoic Thalloid plant body – Unicellular  Non motile: Chlorella  Motile: Chlamydomonas – Multicellular  unbranched filamentous: Spirogyra  Branched filamentous : Chara – Macroscopic sea weed: Sargassum Chlamydomonas Cell wall: cellulose and proteins Pigments : Chlorophyll, xanthophylls and phycobilin. Reserve food material:starch and its other forms Reproduction: vegetative asexual and sexual Spirogyra Life cycle: alternation of generations (n and 2n) TYPES OF ALGAE: CHARACTERISTICS CHLOROPHYCEAE PHAEOPHYCEAE RHODOPHYCEAE Photosynthetic Chl. a & Chl. b Chl. a & Chl. c & fucoxanthin Chl. a & Chl. d & pigments phycoerythrin Reserve food Starch Mannitol, laminarin and starch Floridean starch Cell wall Cellulose Cellulose, fucans and algin Cellulose, pectin and other carbohydrates Habitat Mostly fresh water, at Mostly marine and brackish, at Mostly marine and times marine and times fresh water brackish, at times fresh brackish water water Examples Spirogyra ,chara, Sargassum, Ectocarpus, Fucus, Gelidium , Chondrus, chlamydomonas Laminaria, Petalonia Polysiphonia, Batrachospermum, Porphyra Economic importance of algae: 1. Some green algae are rich in protein, so used as food, used even by space travellers. 2. Some species of brown algae are used for production of hydrocolloids. 3. Commercially important agar-agar used in tissue culture is obtained from red algae. 1 Mithibai College Biology BRYOPHYTA – General Characteristics Amphibians of plant kingdom since habitat is terrestrial but cannot complete life cycle without water Water is needed for fertilization Grows on moist walls, soils Main body – GAMETOPHYTE Body shows caulloid (stem like), phylloid (leaf like) and rhizoids (root like) Vascular tissue absent Heteromorphic alternation of generations – Gametophyte: (n), independent phase, thalloid, leaf like – Sporophyte: (2n), recessive, partially dependent on gametophyte TYPES OF BRYOPHYTES: E.g.Funaria LIVERWORTS / HEPATICEAE (Lower members) MOSSES /MUSCI (Higher members) Dorsiventral, Prostrate plant body Erect plant body Unicellular rhizoids Multicellular rhizoids Examples: LIVERWORTS: Riccia, Marchantia Funaria, Polytrichum, Sphagnum HORNWORTS: Anthoceros Economic importance of Bryophytes Food Sphagnum as peat- fuel, packing material of living material due to good water holding capacity Ecological – first to colonise rocks, decompose, soil formation Dense mats on soil- reduce impact of falling rain, prevent soil erosion, act as soil binders PTERIDOPHYTA - GENERAL CHARACTERISTICS: Vascular, terrestrial, non flowering Called as vascular cryptogams- reason: show presence of vascular bundles, but do not bear seeds and flowers. Main or dominant body (SPOROPHYTE) True roots, stem, pinnate / feather like leaves Heteromorphic alternation of generations Gametophyte: (n), independent Sporophyte : (2n), independent Cambium absent, hence no secondary growth Xylem : only tracheids Phloem : only sieve cells Eg: Aquatic: Azolla, Marselia, Xerophytic : Equisetum Epiphytic: Lycopodium Fern Moist shady places : Nephrolepis Difference between Bryophyes and Pteridophyte Bryophyta Pteridophyta Xylem and Phloem absent Xylem and Phloem Present Plant body shows rhizoid, cauloid and phylloid Plant body shows root, stem and leaves Sporophyte is dependent on gametophyte Sporophyte is not dependent on gametophyte Eg. Funaria, Riccia, Marchantia etc. Eg. Nephrolepis, Equisetum, Azolla etc. 2  Mithibai College Biology GYMNOSPERMAE (Naked seeds) - GENERAL CHARACTERISTICS: Ovules not enclosed in the ovary Evergreen, perennial, woody trees Primive group of flowering plants, Seeds naked, no fruits Main body (Sporophyte)--Roots (tap root), stem (erect, aerial branched in conifers, unbranched in cycas), leaves (foliage, scale) Secondary growth is seen due to presence of cambium In Cycas, corolloid roots seen(symbiotic association with blue green algae), Pinus (Endophytic hyphae – mycorrhizae) Heteromorphic alternation of generations Gametophyte : (n), reduced, dependent Sporophyte : (2n), dominant, independent Male cone- Microsporophyll-microspores Female cone – Megasporophyll--megaspore Cycas fertilization – siphonogamy Examples: Tallest living plant- Sequia & smallest Gymno – Zamia, maximum girth – Taxodium Cycas, Pinus, Ginkgo (Living Fossil) ANGIOSPERMAE- GENERAL CHARACTERISTICS: Most advanced, flowering Seeds within the fruit Roots, stem, leaves Vascular tissue well developed Xylem shows vessels or trachea Phloem shows companion cells, sieve tubes Heteromorphic alternation of generations Sunflower Gametophyte : (n), reduced, dependent Sporophyte : (2n), dominant, independent Maize Androecium -stamens – Anthers – pollen grains- male gametophyte- 2 male gametes (n) Gynoecium - carpel – ovules – megaspores-female gametophyte- egg cell (n) & Secondary nucleus (2n) Pollination indirect, self or cross Fertilisation: Siphonogamy Double fertilization—CHARACTERISTIC FEATURE SEEN ONLY IN ANGIOSPERMS Fusion of one male gamete and egg cell = Zygote (2n) Fusion of second male gamete and secondary nucleus = Endosperm (3n) Ovary and ovule form fruit and seed respectively Examples Wolffia (smallest angiosperm), Eucalyptus CLASSIFICATION OF ANGIOSPERMAE CHARACTERISTICS DICOTYLEDONAE MONOCOTYLEDONAE 1. Number of cotyledons 2 1 2. Root system Tap root system Adventitious root system 3. Leaf venation Reticulate Parallel 4. Stem Profusely branched Rarely branched 5. Flower symmetry Tetra or pentamerous Generally trimerous 6. Vascular bundles Arranged in a ring Scattered in ground tissue 7. Secondary growth Present Absent Examples Helianthus annuus (Sunflower), Hibiscus Zea mays (Maize), Sorghum rosa-sinensis (Shoe flower) vulgare (Wheat) Difference between Gymnosperms and Angiosperms Gymnosperms Angiosperms 1. Seeds are naked 1. Seeds enclosed inside ovary 2. Fruits not formed 2. Fruits are formed due to ripened ovary 3. Calyx and corolla absent 3. calyx and corolla present 4. Double fertilisation absent 4. Double fertilisation is seen. 5. Pollination through wind only 5. Pollination through insects, wind, etc. 3