NEET Biology Class 11 Quick Revision PDF

BIOLOGY NEET NCERT NOTES CLASS 11 QUICK REVISION Biology Simplified Tamil Sl. No: Chapters Page No: 1. The Living World 01 – 05 2. Biological Classification 06 – 13 3. Plant Kingdom 1...

BIOLOGY NEET NCERT NOTES CLASS 11 QUICK REVISION Biology Simplified Tamil Sl. No: Chapters Page No: 1. The Living World 01 – 05 2. Biological Classification 06 – 13 3. Plant Kingdom 14 – 24 4. Animal Kingdom 25 – 38 5. Morphology of Flowering Plants 39 – 52 6. Anatomy of Flowering Plants 53 – 61 7. Structural Organisation in Animals 62 – 75 8. Cell – The Unit of Life 76 – 85 9. Biomolecules 86 – 96 10. Cell Cycle and Cell Division 97 – 102 11. Transport in Plants 103 – 110 12. Mineral Nutrition 111 – 116 13. Photosynthesis in Higher Plants 117 – 125 14. Respiration in Plants 126 – 132 15. Plant Growth and Development 133 – 141 16. Digestion and Absorption 142 – 148 17. Breathing and Exchange of Gases 149 – 154 18. Body Fluids and Circulation 155 – 160 19. Excretory Products and their Elimination 161 – 166 20. Locomotion and Movement 167 – 173 21. Neural Control and Coordination 174 – 180 22. Chemical Coordination and Integration 181 – 188 Living World Characteristics of Living Beings 1) Growth: Increase in mass and no. of cells in body. Fundamental characteristic, intrinsic property. Continuous in plants but upto certain age in animals. Non living organisms also grow → extrinsic growth. E.g: Mountains grow by addition of snow. Unicellular organism grow by cell division. It can't be taken as defining property of living organism. 2) Reproduction: Production of new individuals of same kind by grown up individuals. Fundamental characteristic, it can be sexual or asexual. Some organism like mule, worker bee, sterile human can't reproduce. In unicellular, reproduction is synonymous with growth. It is characteristic of living organisms but not an exclusive feature. It can't be taken as defining property of living organism. 3) Metabolism: Sum total of all chemical reactions occuring inside living organism during processes like photosynthesis, respiration etc. Isolated reaction outside body (in-vitro) are neither living nor non living. It can be considered as defining features of all life forms. 4) Consciousness: Ability to detect changes in environment and respond accordingly. Plants respond to external factors - light, water, temperature. Photoperiod affect reproduction in both plants and animals. Human beings have self consciousness too. Patient in coma virtually supported by machine which replace heart and lungs are neither living nor dead. It is regarded as defining features of all life forms. Diversity in Living World Biodiversity: No. and various kind of organisms found on earth. No. of species that are known and described in the range between 1.7-1.8 million. Nomenclature: Standardised naming of living organism such that a particular organism is known by the same name all over the world. Identification: Determining the features of organism correctly. ICBN: International Code for Botanical Nomenclature. ICZN: International Code for Zoological Nomenclature. ICVN: International Code for Virus Nomenclature. ICNCP: International Code of nomenclature for cultivated plants. Binomial Nomenclature: Universally accepted name with 2 parts. by Carolus Linnaeus. Rules: i) In Latin, written in Italics, if handwritten then underlined. ii) First word starts with capital letter, second word with small letter. First name represent Genus and second species. iii) Author's name after second word i.e. specific epithet. 1 Living World E.g: Mangifera Indica Linn ↓ ↓ ↓ Generic Name Specific epithet Author Name Carolus Linnaeus used ʽSystema Naturaeʼ for animals and ʽSpecies Plantarumʼ for plants. Classification: Grouping organisms in categories, according to similarities and dissimilarities. To make study simple and easier. Systematics: Systematic arrangement of organisms on the basis of evolutionary relationships. From latin word - ʽSystemaʼ. Taxonomic Categories Taxonomy: Branch of science which deals with principles and procedure of classification. Characterisation, identification, classification and nomenclature are basis to taxonomy. Taxa: Specific characteristic shown by specific organism help to assign a category to it. Specific term for these categories - taxa. Taxon: Level of grouping of organism based on certain easily observable common characteristic or each category or unit of classification. All categories constitute heirarchy. i) Species: Organisms with fundamental similarities. E.g: Indica, tuberosum, leo, tigris, nigrum, melongena. ii) Genus: Group of related species. E.g: Solanum, Panthera, Felis. 2 Living World iii) Family: Group of related genera. E.g: Felidae, Canidae, Solanaceae (Genera Solanum, Petunia, Datura). iv) Order: Assemblage of families with similar characters. E.g: Polymoniales (Convolvulaceae, Solanaceae), Primata, Carnivora (Felidae, Canidae). v) Class: Related orders. E.g: Mammalia (order Primata), Insecta. vi) Phylum: Related class. E.g: Chordata, Arthropoda. vii) Kingdom: Related phylum. E.g: Animalia, Plantae. Lower taxa, more characteristics members. Tippy Top (Taxonomical category) King Philip Came Over For Good Soup. Common Name Biological Name Genus Family Order class Phylum/Division. Taxonomical aid: Procedures and technique to store and preserve information and specimens. Herbarium - store house of collected plant specimens that are dried, pressed and preserved on sheet. 3 Living World Sheet carry information like date and place of collection, local and botanical name, family, collector's name etc. Allow morphological study. Botanical garden: Collection of living plants. Grown for indentification, morphological and anatomical study. Each plant is labelled indicating botanical/scientific name and family. E.g: Indian Botanical garden (Howrah), National Botanical Garden (Lucknow), Royal Botanical Garden (Kew, England). Museum: Collection of preserved plant and animal specimen. Preserved in containers or jar in preservative solution (formalin), preserved as dry specimen, collect skeletons of animals also, keep extinct and endangered animals. Insects are preserved in insect boxes after collecting, killing and pinning. Larger animals (bird, mammals) are stuffed and preserved. Zoological park: Wild animals are kept in protected environment under human care which enable us to learn their food habits, behaviour, gestation period. E.g: Jim Corbett National Park, Gir Forest. Conditions similar to natural habitat are provided. Key: Identification of plants and animals based on similarities and dissimilarities. Based on contrasting characters, generally in pair → couplet which represent choice between two opposite options. Each statement in key – lead. Analytical in nature i) Flora: Information about plants in particular area, actual account of habitat and distribution of plants in given area. 4 Living World ii) Manual: Information for identification of names of various species in an area. iii) Monograph: Information of any one taxon. iv) Catalogue: Alphabetical arrangement of species of particular place describing their features. 5 Biological Classification Classification Aristotle: Enaime (have RBCs) and Anaime (absence of RBCs). Linnaeus: Plantae and Animalia. Aristotle used simple morphological characters. But 2 system classification didn't distinguish between eukaryote and prokaryote, unicellular and multicelluar, photosynthetic (green algae) and non-photosynthetic (fungi). 3 Kingdom classification (Haeckel): Protista (aquatic unicellular eukaryote), Animalia, Plantae. 4 Kingdom classification (Copeland): Monera (prokaryote), Protista, Animalia, Plantae. 5 Kingdom classification (R.H. Whittaker) : Monera, Protista, Fungi (heterotrophs), Animalia, Plantae. Used cell structure, body organisation, mode of nutrition, reproduction and phylogenetic relationship. Overcome: Didn’t grouped together unicellular (chlamydomonas) and multicellular (spirogyra), differentiate between heterotrophic (fungi), autotrophic (green plants) as they showed difference in wall compositition – fungi (chitin), plants(cellulosic wall). 6 kingdom classification or 3 domain (carl Woese): Monera was divided into archaebacteria and eubacteria. 1) Kingdom Monera: Sole members are bacteria (most abundant). 6 Biological Classification Some bacteria are autotrophic (synthesise own food from inorganic substrates), majority are heterotrophs (depend on other organism for food). They can be photosynthetic autotroph or chemosynthetic autotroph. i) Archaebacteria: Live in most harsh habitats due to cell wall structure. → Salty area (halophiles). → Hot spring (thermoacidophiles) → Marshy areas (methanogens) -present in gut of ruminant animals like cow, buffaloes and are responsible for production of methane (biogas) from dung. ii) Eubacteria: True bacteria, rigid cell wall, if motile a flagellum present.Photosynthetic autotrophs – E.g: Cyanobacteria (blue green algae). Have chlorophyll a (similar to plants). Unicellular, colonial or filamentous, fresh water/ marine or terrestrial. Colonies are surrounded by gelatinous sheath, often form blooms in polluted water. Some fix atmospheric nitrogen in specialised cell – heterocysts. E.g: Nostoc and anabaena Chemosynthetic autotrophs: Oxidise inorganic substances like nitrate, nitrite, ammonia and use released energy for ATP production, play role in recycling nutrients like N 2, phosphorous,Fe, sulphur. 7 Biological Classification Heterotrophic bacteria: Mostly decomposers, help in making curd from milk, production of antibiotic, fixing N2, in legume, some cause damage to humans, crop, farm, pets, cause diseases like cholera, typhoid, citrus cancer, tetanus. Reproduction: Mainly by fission. Under unfavourable condition produce spores. Sexual reproduction - by adopting primitive type DNA transfer from 1 bacterium to other called Genetic Recombination. Mycoplasma: Lack cell wall, smallest living cell, survive without oxygen, many are pathogenic in plants and animals. 2) Kingdom Protista: Single celled eukaryote (aquatic). Reproduce sexually and asexually with process of cell fusion and zygote formation. i) Chrysophytes: Diatoms and golden algae (desmids). Fresh water and marine, float passively in water current (plankton). In diatoms, cell walls form 2 thin overlapping shells which fit as in soap box, walls have silica so indestructible. They have left behind large deposit in their habitat, this accumulation is diatomaceous earth.Used in filtration, polishing, syrup. Chief producer in ocean. ii) Dinoflagellates: Mostly marine and photosynthetic. Yellow, green, brown, blue red depending on pigment. Cell wall has stiff cellulosic plate on outside. Have 2 flagella - one longitudinal other transverse in furrow. Red ones undergo multiplication, make sea red (red tide), release toxins also. E.g: Gonyaulax. 8 Biological Classification iii) Euglenoids: Mostly in stagnant fresh water. Protein rich layer - pellicle makes it flexible. Pigment is identical to higher plants. E.g: Euglenoid. Have 2 flagella - a short and a long one. Photosynthetic in presence of sunlight, heterotroph in its absence. Undergo longitudinal binary fission. iv) Slime mould: Saprophytic protists. Move along decaying twigs to engulf organic material. In suitable condition - form aggregation (plasmodium). In unfavourable condition - plasmodium differentiate and form fruiting bodies bearing spores at tips. Spores possess true walls, resistant, survive in adverse condition, dispersed by air current. v) Protozoans: Heterotroph, live as predator/parasite. → Amoeboid: Fresh water, sea, soil, move and capture prey by pseudopodia, marine form have silica shell. E.g: Entamoeba (parasite). → Flagellated: Free living or parasitic, have flagella. E.g: Trypanosoma (cause sleeping sickness). →Ciliated: Aquatic, 1000s cilia, have cavity (gullet) that open to outside cell surface, cilia cause water laden food to be steered into gullet. E.g: Paramoecium. 9 Biological Classification → Sporozoans: Have infectious spore like stage called sporozoite. E.g: Plasmodium (malarial parasite) cause malaria. 3) Kingdom Fungi: Heterotrophic. Cosmopolitan, occur in air, water, soil etc., grow in warm and humid places, cell wall – chitin and polysachharide. Filamentous except yeast(unicellular). Have long, slender thread like structures – hyphae. Network of hyphae - myecilium. Some are continuous tubes filled with multinucleated cytoplasm (coenocytic), other have septae or cross wall in their hyphae. Yeast - bread and beer, Puccinia - cause wheat rust Penicillium forms antibiotic penicillin. Most of them absorb organic matter from dead substrates - saprophyte. Some depend on living plants and animals - parasites. They also live as symbionts - with algae (lichens), with roots of higher plants (mycorhiza). Reproduction - Vegetative - fragmentation, fission, budding. Asexual - spores called conidia or sporangiospores or zoospores. Sexual - oospores, ascospores, basidiospores. Various spores are produced in fruiting bodies. → Plasmogamy: Fusion of protoplasm. → Karyogamy: Fusion of 2 nuclei. Meiosis in zygote produce haploid spores. In ascomycetes and basidiomycetes an intervening dikaryotic stage occur- dikaryon and phase – dikaryophase. i) Phycomycetes: Aseptate and coenocytic myecilium. Aquatic and on decaying wood in moist and damp places. Asexual by zoospores or aplanospores (non - motile) → endogenous. Sexual by isogamous or anisogamous or oogamous gametes. E.g: Rhizopus (bread mould), Mucor, Albugo (Parasitic fungi). ii) Ascomycetes: Sac fungi, branched and septate myecilium. Mostly multicelluar - E.g: Penicillium, rarely unicellular - E.g: Yeast. Saprophytic, decomposers, parasitic or coprophilous (grow on dung). Exogenous conidia - conidiophores, sexual spores - endogenous ascospores in sac like asci arranged in fruiting bodies – ascocarp. E.g: Claviceps, Aspergillus, Neurospora (biochemical and genetic work), Morels and truffels (edible). 10 Biological Classification iii) Basidiomycetes: Mushrooms, bracket fungi, puffballs. Branched and septate mycelium. Grow in soil, logs, tree stumps, live as parasite. E.g: Rust, smut. Asexual spores aren't found, vegetative reproduction is common. Sex organs are absent, dikaryotic phase gives rise to basidium. Karyogamy and meiosis results in 4 basidiospores (exogenous). Basidia are arranged in basidiocarp. E.g: Agaricus (mushroom), Ustilago (smut), Puccinia (rust fungus). iv) Deuteromycetes: Imperfect fungi, septate and branched mycelium. Only asexual or vegetative phases are known. When sexual phase were known they were moved to ascomycetes and basidiomycetes. Reproduce only by asexual spore-conidia. Help in mineral cycling and decomposers of litter. E.g: Alternaria, Colletotrichum, Trichoderma. 4) Kingdom Plantae: Eukaryotic chlorophyll containing organism. Some are insectivorous. E.g: Bladderwort and Venus fly trap Cuscutta (parasitic). Have 2 phases - diploid sporophytic and haploid gametophytic. Show alternation of generation. 5) Kingdom Animalia: Heterotrophic eukaryotic organism, lack cell wall. Food reserve as glycogen, holozoic mode of nutrition. Capable of locomotion. 6) Viruses, Viroids, Prions and Lichens: i) Virus: Non cellular organisms that have inert crystalline structure outside cell. once they infect cell they take over machinery of host cells to replicate themselves killing host. 11 Biological Classification Pasteur: Virus means venom. DJ. Ivanowsky (1892): Recognised microbes as casual organism of mosaic disease of tobacco, smaller than bacteria as passed through bacteria proof filters. M.W. Beijerinek (1898): Extract of infected plant of tobacco cause infection called Contagium Vivum Fluidum. W. M Stanley (1935): Virus could be crystallised, crystals consist of protein. Virus are obligate parasites, no virus contain both RNA and DNA. Virus is nucleoprotein and has infectious genetic material. Virus that infect plants have singly stranded RNA, that infect animals have single or double stranded RNA or double stranded DNA. Bacteriophage (virus infecting bacteria) have double stranded DNA. Protein coat - capsid, has small subunits - capsomere (protect nucleic acid). They are arranged in helical or polyhedral form. Disease: Mumps, small pox, herpes, influenza, AIDS, Covid-19. Mosaic formation, leaf rolling, yellowing, vein clearing, stunted growth are symptoms. ii) Viroids: T.O. Diener (1971) - Smaller than virus, cause potato spindle tuber disease, have free RNA (low molecular weight). iii) Prions: Abnormally folded protein, similar size of virus, cause Bovine Spongiform Encephalopathy (BCE) commonly mad cow disease in cattle analogous to Cr Jacob in humans. 12 Biological Classification iv) Lichens: Symbiotic association between algae and fungi. Algae prepare food and fungi provide shelter and absorb mineral and nutrients. Algal component - phycobiont, fungal component - mycobiont. Lichen don't grow in polluted area i.e. pollution indicators, mainly SO2 pollution indicator. 13 Plant Kingdom Classification systems 1) Artificial system: Earliest, given by Linnaeus. Used only superficial morphological characters - habit, colour, number. Based on vegetative characters or on androecium structure. Separated closely related species as based on few characteristics. Equal weightage to vegetative and sexual characteristics but vegetative characters are easily affected by environment. 2) Natural system: By George Bentham and Joseph Dalton Hooker. Based on natural affinities among organisms. Not only external features but also internal features like ultra structure, anatomy, embryology and phytochemistry. 3) Phylogenetic system: Based on evolutionary relationship of organisms. Assume organisms belonging to same taxa have common ancestor. 4) Phenetic classification: Based on affinities, similarities or dissimiliarities of organism. Some evidences are: a) Numerical taxonomy: Using computers. Based on observable characters. No. and codes are assigned to all characters. Each character is given equal importance. 100s of characters can be considered at same time. b) Cytotaxonomy: Based on cytological information - chromosome no., structure, behaviour. c) Chemotaxonomy: Use chemical constituent of plant/organism like aminoacids, proteins, DNA sequence. ALGAE: Chlorophyll bearing, simple, thalloid, autotrophic, largely aquatic, occur in moist stones, soil, wood, occur in association with fungi (Lichen) and with animals (E.g: sloth bear). Can be colonial (Volvox) or filamentous (Ulothrix and spirogyra). Reproduction i) Vegetative - fragmentation (each fragment develops into thallus). ii) Asexual - by spores, mostly flagellated zoospores (motile). iii) Sexual - fusion of 2 gametes. a) Isogamous: Flagellated & similar - Ulothrix; non flagellated & similar – Spirogyra. b) Anisogamous: Fusion of 2 gametes dissimilar in size. E.g: Udorina. c) Oogamous: Fusion between 1 large, non motile female gamete and smaller, motile male gamete. E.g: Volvox, Fucus. Economic importance Half carbon dioxide on earth is fixed by algae. Being photosynthetic, increase level of dissolved oxygen. Primary producers of energy rich compounds. E.g: Porphyra, Laminaria & Sargassum are used as food. Produce hydrocolloids (water holding substances). E.g: Algin (brown algae & Carageen (red algae). 14 Plant Kingdom Agar from Gelidium & Gracilaria are used in icecream & jellies. Chlorella (unicellular algae) rich in protein is used as food supplement by space travellers. 1) Chlorophyceae : Green algae. May be unicellular, colonial, filamentous. Pigment: Chlorophyll a, chlorophyll b. Chloroplast: May be discoid, plate like, reticulate, cup shape (chlamydomonas), spiral, ribbon shape. Pyrenoids: One or more storage bodies, have protein & starch, store food in form of oil droplets also. Cell wall: Inner cellulosic outer pectose. Habitat: Fresh water, brackish water, salt water. Flagella: 2, 8 equal, apical position. Reproduction → Vegetative - fragmentation. → Asexual - flagellated zoospores in zoosporangia. → Sexual - isogamous, anisogamous, oogamous. E.g: Chlamydomonas, Volvox, Ulothrix, Spirogyra, Chara. 2) Phaeophyceae: Brown algae. Mostly marine. Range from simple branched, filamentous (Ectocarpus) to profusely branched (Kelps) – 100 metres tall. Pigment: Chlorophyll a, chlorophyll c, carotenoid, xanthophyll, fucoxanthin (responsible for colour from green to brown). Food storage: Laminarin or mannitol. Cell wall: Cellulose + gelatinous coating of algin (non sulphated). Protoplast: Plastids + vacuole + nucleus. Plant body: Attached to substratum by holdfast, has stalk, stipe and leaf like photosynthetic organ – frond. Habitat: Fresh water (rare), brackish water, salt water. Flagella: 2, unequal, lateral. Reproduction → Vegetative: Fragmentation. → Asexual: Biflagellated zoospores (pear shape with 2 unequal flagella). → Sexual: Isogamous, anisogamous, oogamous (pear shaped gamete). E.g: Ectocarpus, Dictyota, Laminaria, sargassum, fucus. 3) Rhodophyceae: Red algae, multicellular. Majority marine with higher concentration in warmer areas. Occur in well lighted region close to water surface & at great depth. Pigment: r - phycoerythrin, chlorophyll a, chlorophyll d. Food storage: Floridean starch similar to amylopectin & glycogen. Cell wall: Cellulose, pectin, polysulphate esters. Habitat: Fresh water (some), brackish water, salt water (most). Flagella: Absent. Reproduction → Vegetative: Fragmentation. → Asexually: Non motile spores. 15 Plant Kingdom → Sexually: Non motile gametes, oogamous. E.g: polysiphonia, Porphyra, Gracilaria, Gelidium. 16 Plant Kingdom BRYOPHYTES: Amphibian of plant kingdom. Moist shaded areas in hills, damp, humid, shaded areas. Dependent on water for sexual reproduction. Important role in plant succession on bare rocks. Thallus like, prostrate or erect. Attached to sustratum by unicellular or multicellular rhizoids. Lack true roots, stem or leaves because vascular bundles are absent. Haploid, sex organs - multicellular (Jacketed). Produces gamete – Gametophyte. Male sex organs - antheridium, produce biflagellated antherozoids. Female sex organs - archegonium (flask shaped, produce single egg). Antherozoids are released in water, fused with egg when come in contact with archegonium and produce zygote. Zygote don't undergo reduction division immediately & produce multicellular body – sporophyte which is not free - living & attached to photosynthetic gametophyte & derive nourishment (semiparasite). Some of its cell undergo meiosis & produce haploid spores which germinate to give gametophyte. Economic Importance: Some mosses provide food for herbaceous mammals, birds. Sphagnum (moss) provide peat which is used as fuel and as packing material for trans – shipment of living material due to good water holding capacity so called Peat Moss. Mosses & lichens are first to colonise rocks. Mosses reduce impact of falling rain & soil erosion as they form dense mats on the soil. 1) LIVERWORT: E.g: Marchantia. Grow in moist, shady, marshy habitat, bark of trees, woods. Thalloid plant body, dorsiventral thallus closely appressed to substrate. Tiny leaf like appendages in 2 rows on thallus called scales. Reproduction: → Asexual: Fragmentation or by specialised structure – gemmae. Gemmae: Green, multicellular, asexual bud, develop in small receptacle - gemma cups on thalli. Gemmae detach and germinate to form new individual, one gammae produced two new thallus. 17 Plant Kingdom → Sexual: Male and female sex organs either on same or different thalli. Sporophyte is differentiated into foot, seta & capsule. After meiosis spores are produced within capsule which germinate to form free living gametophytes. 2) MOSSES: E.g: Funaria, Polytrichum, Sphagnum. First stage is protonema which develop directly from spore. Its a creeping, green, branched & frequently filamentous stage. Second stage is leafy stage called Gametophore which develop from secondary protonema as lateral bud. It has upright, slender axes bearing spirally arranged leaves. It bears sex organs and attached to soil through multicellular & branched rhizoids. Reproduction: → Vegetative - fragmentation & budding in secondary protonema. → Sexual - after fertilisation antherozoids and egg cell, produced diploid oospore which develops into sporophyte (foot, seta, capsule) where capsule contains spores which are produced after meiosis. PTERIDOPHYTES: Horsetails & ferns. Usually for medicinal purpose & soil binders, ornamentals. First terrestrial plants with vascular tissues. Found in cool, damp, shady places. 18 Plant Kingdom Main plant body is sporophyte, differentiated into true roots, stem & leaves. Leaves can be small (microphyll) - Selaginella or large (macrophyll) – Ferns. Sporophyte bear sporangia subtended by leaf like appendages sporophylls which form strobili or cones (Selaginella, Equisetum). Sporangia produce spores by meiosis which give rise to small, multicellular, free living, photosynthetic thalloid gametophyte - prothallus which require specific habitat. Water is required for transfer of antherozoids to mouth of archegonium. Fusion results in zygote which produce multicellular sporophyte. Homosporous: Same kind of spores. E.g: Majority. Heterosporous: 2 kinds of spores (micro & macro). E.g: Selaginella, Salvinia. Development of zygote into embryo occur within female gametophyte. It is a precursor to seed habit. 19 Plant Kingdom GYMNOSPERMS: Naked Seeded Plant. Ovules are not enclosed by ovary wall, remain exposed both before & after fertilisation. Sequoia: Tallest redwood tree (gymnosperm). Generally tap root. Roots in some species have fungal association (mycorrhiza). E.g: Pinus and in some coralloid roots are associated with N2 fixing cyanobacteria. E.g: Cycas. Stems are unbranched in cycas and branched in Pinus, Cedrus. Leaves may be simple or compound. Pinnate leaves persist for few years in cycas. Leaves are adapted to extreme temperature, humidity & wind. In conifers, needle like leaf reduce surface area, thick cuticle & sunken stomata reduce water loss. Heterosporous - haploid microspores & megaspores. 2 kinds of spores are produced within sporangia born on sporophyll which are spirally arranged on axis to form strobili or cones. Strobili bearing microsporophylls & microsporangia - male strobili or microsporangiate. Microspore develop to male gametophyte (pollen grain) which is highly reduced & has limited no. of cells. Cones bearing megasporophyll or megasporangia – female strobili or macrosporangiate. Male & female cones may be borne on same tree in Pinus & on different trees in Cycas. Megaspore mother cell is differentiated from one of the cells of nucellus, protected by envelopes & composite structure – ovule. Megaspore mother cell divide meiotically to form 4 megaspores. One of the megaspore enclosed in megasporangium develops into multicellular female gametophyte that bears 2 or more archegonia. 20 Plant Kingdom Unlike bryophytes & pteridophytes, male & female gametophytes don't have independent existence in gymnosperms. They remain within sporangia (short lived gametophyte stage). Pollen grains are carried by air current & come in contact with ovule on megasporophyll. Pollen tube with male gametes grow towards archegonia & discharge their contents. After fertilisation, zygote develops into embryo & ovules into seeds. E.g: Cycas, Pinus, Ginkgo, Cedrus. ANGIOSPERMS Pollen grains & ovules are developed in flowers. Seeds are enclosed in fruits. Range from smallest Wolfia to tall trees of Eucalyptus (100 m). Provide food, fodder, fuel, medicines. Dicotyledons - 2 cotyledons, reticulate venation, tetramerous or pentamerous flowers i.e. 4 or 5 members in each floral whorl. Monocotyledons - 1 cotyledon, parallel venation, trimerous flowers. Male sex organ is stamen, which has slender filament with anther at tip. 21 Plant Kingdom Within anther, pollen mother cell divide by meiosis to produce microspores which mature to form pollen grains. Female sex organ is pistil, consist of ovary base, long slender style, stigma. Inside ovary, ovule is present. Each ovule has megaspore mother cell that undergo meiosis to form 4 haploid megaspores. 3 degenerate & 1 divide to form embryo sac which has 3 celled egg apparatus – 1 egg cell, 2 synergid, 3 antipodals, 2 polar nuclei. Polar nuclei fuse to produce diploid secondary nucleus. Pollination - transfer of pollen grains by wind or other agencies to stigma of pistil. Pollen grains germinate & pollen tube grow through tissues of stigma & style & reach ovule & discharge 2 male gamates. 𝑺𝒚𝒏𝒈𝒂𝒎𝒚 One fuses with egg cell → zygote; other fuses with diploid secondary nucleus 𝒕𝒓𝒊𝒑𝒍𝒆 𝒇𝒖𝒔𝒊𝒐𝒏 → triploid primary endosperm nucleus (PEN). This is double fertilisation. Zygote develops to embryo & PEN develops into endosperm. 22 Plant Kingdom Synergids and antipodals degenerate after fertilisation. ovules develop to seeds & ovaries into fruit. Plant Life Cycle & Alternation of Generations In plants, both haploid & diploid cells can divide by mitosis. Haploid plant produce gamete be mitosis, following fertilisation. Zygote also divide by mitosis to produce diploid sporophytic plant body. Haploid spores are produced by meiosis, which inturn divide by mitosis to form haploid plant body. So there is alternation of generation between gamete producing haploid gametophyte & spore producing diploid sporophyte. 1) Haplontic – E.g: Volvox, Spirogyra, Chlamydomonas. Sporophytic generation is represented by 1 celled zygote, no free living sporophyte. Dominant phase is free living gametophyte. 2) Diplontic – E.g: Fucus, Gymnosperm, Angiosperm. Diploid sporophyte is dominant, photosynthetic, independent phase of plant. Gametophyte is represented by few celled stage. 23 Plant Kingdom 3) Haplo – diplontic – E.g: Bryophyte, Pteridophyte. Both phases are multicelleluar. Bryophyte: Dominant, independent, photosynthetic phase is haploid gametophyte, sporophyte is dependent on it for anchorage & nutrition. Pteridophyte: Dominant is diploid sporophyte, alternate with multicellular, independent but short lived haploid gametophyte. E.g: Some algae like Ectocarpus, Polysiphonia, Kelps. 24 Animal Kingdom Basic of Classification 1) Levels of Organisation: → Cellular: Loose cell aggregate. E.g: Sponges. → Tissue level: Cell performing same function are arranged. E.g: Cnidaria and Ctenophora. → Organ level: Tissues group to form organ. E.g: Platyhelminthes. → Organ system level: Associated organ. E.g: Annelida, Arthropoda and all vertebrates. Digestive system: → Complete: 2 openings mouth & anus. E.g: Aschelminthes to chordata. → Incomplete: Single opening acts as both mouth and anus. E.g: Platyhelminthes, Coelentrata/Cnidaria, Ctenophora. Circulatory system: From Annelida to chordata. → Open: Blood is pumped out & cells are directly bathed in it. E.g: Arthropoda. → Closed: Blood is circulated through vessels of different diameter. E.g: Annelida and all chordates. 2) Symmetry: → Assymmetrical: No plane through centre divides into 2 halves. E.g: Sponges. → Radial: Any plane through centre divides into 2 half. E.g: Coelentrate, Ctenophore, Echinoderm. → Bilateral: Only one plane divides into 2 equal half. E.g: Annelids, arthropoda etc. 25 Animal Kingdom 3) Diploblastic & Triploblastic: → Diploblastic: Cells are arranged in 2 embryonic layers, external ectoderm & internal endoderm. Undifferentiated mesoglea is present between them. E.g: Coelentrates. → Triploblastic: Developing embryo has third germinal layer - mesoderm in between ectoderm & endoderm. E.g: Platyhelminthes to Chordates. 4) Coelom: Body cavity lined by mesoderm on both sides. → Coelomates: Possess coelom. E.g: Annelids, Molluscs to Chordates. → Pseudocoelomates: Mesoderm as scattered pouch. E.g: Aschelminthes. → Acoelomates: Body cavity is absent. E.g: Platyhelminthes. 5) Segmentation: → External & internal division in segments with serial repetition. E.g: Earthworm show metamerism (metameric segmentation)/true segmentation and false segmentation found in tapeworm. 6) Notochord: Mesodermally derived rod like structure on dorsal side. → Animals with notochord: Chordates. → Animals without notochord: Non chordate. E.g: Porifera to Echinoderms. 26 Animal Kingdom Classification of Animals: 1) Phylum – Porifera: (Sponges) Generally marine, assymmetric, cellular level organisation. Multicellular with water transport or canal system. Water enters through minute pores (ostia) in body wall into spongocoel, where it goes out through osculum. It helps in food gathering, respiration & excretion. Choanocyte (collar cell) line spongocoel, helps in intracellular digestion. Skeleton is made up of spicules or spongin fibres. Sexes aren't separate (hermaphrodite), digestive system absent. Internal fertilisation & indirect development (larval stage). E.g: Sycon (scypha), Spongilla (fresh water sponge), Euspongia (Bath sponge). 27 Animal Kingdom 2) Phylum – Coelentrata: (Cnidaria) Aquatic, mostly marine, radial symmetry, diploblastic, tissue level of organisation. Cnidoblast/cnidocytes - Contain stinging capsules or nematocysts on tentacles, used for anchorage, defense & capturing prey. Have central gastro vascular cavity with single opening mouth on hypostome, extracellular & intracellular digestion takes place. Corals have CaCO3 skeleton. Exhibit 2 forms – Polyp - Sessile, cylindrical. E.g: Hydra, Adamsia etc. Medusa - Umbrella shaped, free living. E.g: Aurelia, Jelly Fish etc. Species existing in both forms - Metagenesis.i.e. Polyp produce medusae asexually & medusae form polyp sexually. E.g: Obelia. E.g: Physalia (Portuguese man of war), Adamsia (Sea anemone), Pennatula (Sea pen), Gorgonia (Sea fan), Meandrina (Brain coral). 3) Phylum – Ctenophora: (sea walnuts/comb jellies) Exclusively marine, radial symmetry, diploblastic, tissue level of organisation. 8 external rows of ciliated comb plates (locomotion). 28 Animal Kingdom Intracellular & extracellular digestion. Bioluminescence (property of living organism to emit light). Sexual reproduction, hermaphrodite, external fertilisation with indirect development. E.g: Pleurobrachia & Ctenoplana. 4) Phylum – Platyhelminthes: Dorso ventrally flattened → flatworms. Endoparasites & free living, bilateral symmetry, triploblastic, acelomate, organ level. Hooks & suckers to absorb nutrient from host & for attachment. Flame cells help in osmoregulation & excretion. Hermaphrodite, internal fertilisation, indirect development. Planaria - High regeneration capacity. E.g: Taenia (Tapeworm), Fasciola (Liver Fluke). 5) Phylum – Aschelminthes: Circular body in cross section → Roundworm. May be free living, aquatic or terrestrial or parasitic. 29 Animal Kingdom Organ system level, bilateral symmetry, triploblastic, pseudocoelomate, dioecious (separate sex). Complete digestive system with well developed muscular pharynx. Often females are longer than males, sexual dimorphism is clearly seen. Internal fertilisation, direct development or indirect. E.g: Ascaris (Round worm), Wuchereria (Filarial worm), Ancylostoma (Hookworm). 6) Phylum – Annelida: May be aquatic or terrestrial, free living or parasitic. Organ system level, bilateral symmetry, triploblastic, coelomate, metamerically segmented, has metameres (segment). Possess longitudinal & circular muscles for locomotion. Aquatic annelids like Nereis possess lateral appendages, parapodia which help in swimming, dioecious (unisexual). Closed circulatory system, earthworm & leech - monoecious (Hermaphrodite). Nephridia for osmoregulation & excretion. Paired ganglia connected by lateral nerves to double ventral nerve cord. E.g: Nereis, Pheretima (Earthworm), Hirudinaria (Blood sucking leech). 30 Animal Kingdom 7) Phylum - Arthropoda (Insects) Largest phylum (2 – 3rd of all species on earth). Organ system level, bilateral symmetry, triploblastic, coelomate. Segmented, chitinous exoskeleton, open circulatory system. Body consist of head, thorax & abdomen, have jointed appendages. Respiratory organs - gills, book gills, book lungs or tracheal system. Sensory organs - antennae, eyes (compound & simple), statocysts or balancing organ. Excretion through malpighian tubules, dioecious, oviparous. Internal fertilisation, direct or indirect development. E.g: Economically important - Apis (Honey bee), Bombyx (silkworm), Laccifer (lac insect), Vectors - Anopheles, culex & Aedes (Mosquito), Gregarious pest - Locusta (Locust), Living fossil - Limulus (King crab). 8) Phylum – Mollusca: Second largest animal phylum. Terrestrial or aquatic, organ system level, bilateral symmetry. Triploblastic, coelomate, dioecious, oviparous, indirect development. Calcareous shell, unsegmented with head, muscular foot, visceral hump. Soft & spongy layer of skin forms mantle over hump. Mantle cavity - space between hump & mantle, gills are present. Anterior head has sensory tentacles. Radula – file like rasping organ for feeding in mouth. E.g: Pila (Apple Snail), Pinctada (Pearl Oyster), Sepia (cuttle fish), Loligo (Squid), Octopus (Devil fish), Aplysia (Sea hare), Dentalium (Tusk shell), Chaetopleura (Chiton). 31 Animal Kingdom 9) Phylum – Echinodermata: Exclusively marine, organ system level, triploblastic, coelomate, dioecious. Calcareous endoskeleton, excretory system absent. Adult - radial symmetry, larva - bilateral symmetry. Complete digestive system with mouth on ventral (lower) & anus on dorsal. Distinctive feature - water vascular system (locomotion, respiration, capture & transport of food). External fertilisation, indirect development. E.g: Asterias (Star fish), Echinus (Sea urchin), Antedon (Sea lily), Cucumaria (Sea cucumber), Ophiura (Brittle star). 10) Phylum – Hemichordata: (Worm like marine animals) Organ system level, bilateral symmetry, triploblastic, coelomate. Stomochord - Rudimentary structure in collar region, similar to notochord. Cylindrical body with proboscis, collar & trunk. Open circulatory system, excretion - proboscis gland. Gills for repriration, dioecious, external fertilisation, indirect development. E.g: Balanoglossus & Saccoglossus. 32 Animal Kingdom 11) Phylum – Chordata: Segmented Bilateral symmetry, triploblastic, coelomate, organ system level. Chordata is divided into three subphyla: Urochordata or Tunicata, Cephalochordata and Vertebrata. Subphyla Urochordata and Cephalochordata are often referred to as protochordates and are exclusively marine. i) Urochordata – Notochord only in larval tail. E.g: Ascidia, salpa, Doliolum. 33 Animal Kingdom ii) Cephalochordata – Persistent notochord from head to tail. E.g: Branchiostoma (Amphioxous or Lancelet). iii) Vertebrata – Notochord during embryonic period. Notochord is replaced by cartilagenous or bony vertebral column in adult. All vertebrates are chordates but all chordates are not – vertebrate. Vertebrates have 2, 3 or 4 chamber ventral muscular heart, kidney for excretion & osmoregulation, paired appendages. a) Class – Cyclostomata: Some are endoparasite on fish, elongated body. 6 - 15 pairs of gill slits, sucking & circular mouth without jaws. No scales, paired fins, closed circulation. Cartilagenous cranium & vertebral column. Marine but migrate to fresh water for spawning, then die. Larva after metamorphosis return to ocean. E.g: Petromyzon (Lamprey) & Myxine (Hag fish) b) Class – Chondrichthyes: Marine with stream lined body, cartilagenous endoskeleton, dioecious. Persistent notochord, ventral mouth, tough skin, placoid scales. Separate gill slits without operculum, powerful jaws. Teeth are modified scales, predaceous, 2 chamber heart (one auricle & one ventricle). Air bladder absent, poikilothermous (cold blooded). Some have electric organ (E.g: Torpedo) & some posess poison sting (E.g: Trygon). Pelvic fins bear claspers in males. Internal fertilisation, viviparous. E.g: Scoliodon (Dog fish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Sting ray). 34 Animal Kingdom c) Class – Osteichthyes: Marine & fresh water, bony endoskeleton, streamlined body. Terminal mouth, 4 pair gills with operculum, cycloid scales. Air bladder present (buoyancy), 2 chamber heart, cold blooded (Poikilothermic). Dioecious, external fertilisation, direct development, oviparous. E.g: Marine - Exocoetus (Flying fish), Hippocampus (Sea horse). Freshwater - Labeo (Rohu), Catla (Katla), Clarias (Magur). Aquarium - Betta (Fighting Fish), Pterophyllum (Angel Fish). d) Class – Amphibia: Aquatic + terrestrial. 2 pair limbs, body - head + trunk, tail may be present, neck absent. Moist skin without scales, eyelids present, tympanum represent ear. Respiration by gills, lungs, skin, 3 chamber heart, dioecious. External fertilisation, indirect development, oviparous. 35 Animal Kingdom Cloaca – common chamber for alimentary canal, urinary & reproductive tract which opens to exterior. E.g: Bufo (Toad), Rana (Frog), Hyla (Tree frog), Salamandra (Salamander), Ichthyophis (Limbless Amphibia). e) Class – Reptilia: Creeping or crawling locomotion. Terrestrial, dry cornified skin with epidermal scales or scutes. Tympanum represent ear, 2 pair of limb if present. 3 chambered heart but 4 chambered in crocodiles. Poikilothermous, dioecious, internal fertilisation, oviparous. Direct development, snakes & lizard shed their scales. E.g: Chelone (Turtle), Testudo (Tortoise), Chameleon (Tree Lizard), Calotes (Garden Lizard), Crocodilus (crocodile), Alligator (Alligator), Hemidactylus (Wall Lizard). Poisonous – Naja (Cobra), Bangarus (Krait), Vipera (Viper). f) Class – Aves: Feathers present, beak present, forelimbs modified to wings. Hind limbs have scales, help in walking, swimming etc. Flightless bird, E.g: Ostrich, 4 chambered heart. Dry skin without glands (except oil gland at tail base). Bony endoskeleton, hollow with air cavity (pneumatic). Digestive tract have crop & gizzard, dioecious. Warm blooded (homoiothermous) - maintain constant body temperature. Respiration by lungs, supplemented by air sacs. Internal fertilisation, direct development, oviparous. 36 Animal Kingdom E.g: Corvus (Crow), Columba (Pigeon), Psittacula (Parrot), Pavo (Peacock), Struthio (Ostritch) , Aptenodytes (Penguin), Neophron (Vulture). g) Class – Mammalia: Found in ice caps, desert, mountain, forest, caves, grassland. Milk producing glands (mammary gland) to nourish young ones. 2 pair of limbs for walking, running, burrowing, flying etc. Hair on skin, external ear (Pinnae) present. 4 chambered heart, warm blooded, different types of teeth. Respiration by lungs, dioecious, internal fertilisation. Direct development, viviparous with exception. E.g: Oviparous - Ornithorhynchus (Platypus), Viviparous - Macropus (Kangaroo), Pteropus (Flying fox), Camelus (Camel), Macaca (Monkey), Rattus (Rat), Canis (Dog), Felis (Cat), Elephas (Elephant), Equus (Horse), Delphinus (Dolphin), Balaenoptera (Blue Whale), Panthera tigris (Tiger), Panthera Leo (Lion). Some Features: Segmentation: Annelida, Arthropoda & Chordata. Digestive system: Aschelminthes to Chordata. Circulatory system: Annelida to Chordata. Respiratory system: Arthropoda to Chordata. 37 Animal Kingdom 38 Morphology of Flowering Plants Morphology: External structure study. The Root: Direct elongation of radicle - primary root which grow inside soil, positively geotropic. Lateral roots of primary root - secondary, tertiary etc. roots. Water absorption, proper anchorage to plant parts, storing reserve food material, synthesis of plant growth regulator, mineral absorption. 1) Tap root system: Primary roots & its branches. E.g: Mustard. 2) Fibrous root system: Roots originating from base of stem. E.g: Wheat. 3) Adventitious roots: Roots arising from parts other than radicle. E.g: Grass, monstera, banyan. ln monocots, primary root is short lived & replaced by large number of fibrous roots. 39 Morphology of Flowering Plants Regions of the Root: Root is covered by thimble like structure at apex - root cap. (Protects tender apex of roots) 1) Meristematic region: Few millimetre above root cap, divide rapidly, small, thin walled cell with dense protoplasm. 2) Elongation region: Cells undergo rapid elongation & enlargement, help in growth of root in length. 3) Maturation region: Epidermal cells form fine, delicate, thread like structure - root hairs (absorb water & minerals). Modification of Root – To perform more functions. 1) Storage: Tap root of carrot, turnip; adventitious roots of sweet potato; asparagus. 2) Prop: Roots become hanging structure to support tree. E.g: Banyan 3) Stilt: Supporting roots come out of lower nodes of stem. E.g: Sugarcane, maize. 4) Pneumatophores: Roots come out of ground & grow vertically upwards, swampy areas, help to get O2 for respiration. They are positively phototropic and also called respiratory roots. E.g: Rhizophora. 40 Morphology of Flowering Plants The Stem: Positively phototropic. Ascending part of axis bearing branches, leaves, flowers & fruits. Develops from plumule of embryo of germinating seed. Region of stem where leaves are born – nodes. Space between 2 nodes – internode. Green when young & later become woody & dark brown. Conducts water, mineral & photosynthates (when green). Modifications of Stem: 1) Storage: Underground stem of potato, ginger, turmeric, zaminkand, colocasia; organ of perennation in unfavourable condition. 2) Tendrils: Develop from axillary buds, spiral, slender, help plants to climb. E.g: Gourds (cucumber, pumpkin, watermelon), grapevine. 3) Thorns: Axillary buds modify into woody, straight, pointed structure. E.g: Citrus & Bougainvillea; protect from browsing animals. 41 Morphology of Flowering Plants 4) Runner: Lateral branches originate from basal & underground portion of main stem, grow horizontally beneath soil, come out obliquely upward. E.g: Banana, Chrysanthemum, pineapple. 5) In arid region, stems are modified to flattened (E.g: Opuntia called phylloclade) or fleshy. (E.g: Euphorbia) structure which contain chlorophyll. 6) Underground stem spread to new niches & when older die, new arise. E.g: Grass, strawberry. 7) Lateral branch arise from base of main axis, arch downward after growing aerially to touch the ground. E.g: Mint, jasmine. 8) Lateral branch with short internode & each node bearing rosette of leaves & tuft of roots are found in aquatic plants. E.g: Pistia & Eichhornia (water hyacinth). The leaf: Lateral, flattened, develops at node, bears bud in axil. Axillary bud develops into branch. Originate from shoot apical meristem as lateral outgrowth, acropetal order. Parts of Leaf: → Lamina/Leaf blade: Green expanded part with vein & veinlets. → Petiole: Hold blade to light, allow leaf blade to flutter, cools leaf, brings fresh air to surface. → Leaf base: Attached to stem, may bear 2 small leaf like structure (Stipules). In legumes, its swollen (Pulvinus). In monocots, it expands into sheath covering stem. Midrib: Middle prominent vein. Veins: Provide rigidity to leaf, transport water, minerals. Venation: Arrangement of veins & veinlets in lamina. 42 Morphology of Flowering Plants 1) Reticulate: Veinlets form network. E.g: Dicots. 2) Parallel: Veinlets run parallel within lamina. E.g: Monocots. Types of Leaves: → Simple: Incisions don't touch the midrib. → Compound: Incisions reach midrib breaking into no. of leaflets. Pinnately - No. of leaflets on common axis (rachis). E.g: Neem. Palmately - leaflets attached to common point (tip of petiole). E.g: Silk cotton. * Bud is present in axil of petiole in both simple & compound leaf but not in axil of leaflets of compound leaf. 43 Morphology of Flowering Plants Phyllotaxy: Pattern of arrangement of leaves on stem. 1) Alternate: Single leaf at each node in alternate manner. E.g: China Rose, mustard, sunflower. 2) Opposite: Pair of leaves at each node & opposite to each other. E.g: Calotropis, guava. 3) Whorled: More than 2 leaves at node, form whorl. E.g: Alstonia. Modification of Leaves: 1) Tendril: Climbing. E.g: Peas. 2) Spines: Defense. E.g: Cacti, Bougainvillea. 3) Bulb: Fleshy leaves of onion & garlic. 4) Insectivorous: Pitcher plant, venus fly trap. * Australian Acacia - small & short lived leaves & petiole is modified into leaf called phyllode. 44 Morphology of Flowering Plants The Inflorescence: Arrangement of flowers on floral axis. * When shoot tip transforms into flower its solitary. 1) Racemose: Main axis continue to grow, flowers in acropetal succession. 2) Cymose: Main axis terminates in flower, limited growth, basipetal order. The flower: Reproductive unit in angiosperms. 4 whorls on swollen end of stalk (pedicel) called thalamus or receptacle. Accessory organ - calyx & corolla. Reproductive organ - Androecium & gynoecium. If calyx & corolla aren't distinct - Perianth. E.g: lily. 1) Sex : Bisexual - Both androecium & gynoecium in 1 flower. Unisexual - Either stamen or only carpel. 2) Symmetry: Actinomorphic - 2 equal half from any plane → through centre. E.g: Mustard, chilli, datura. Zygomorphic - 2 similar half from 1 plane. E.g: Gulmohar, Pea, bean, cassia. Assymmetric - Can't be divided into 2 equal half. E.g: Canna. 3) Floral appendages: Trimerous - multiple of 3 45 Morphology of Flowering Plants Tetramerous - multiple of 4 Pentamerous - multiple of 5 4) Bracts: Reduced leaf at base of pedicel (floral axis). With Bracts - Bracteate, without Bracts – ebracteate. 5) Position of calyx, corolla & androecium with respect to ovary: i) Hypogynous: Highest position of gynoecium, other parts below it, superior ovary. E.g: China rose, brinjal, mustard. ii) Perigynous: Gynoecium in centre & other parts on rim of thalamus, half inferior ovary. E.g: Plum, rose, peach. iii) Epigynous: Thalamus grows upward enclosing ovary, other parts above ovary, inferior ovary. E.g: Guava, cucumber, ray floret of sunflower. Parts of flower A) Calyx - Outermost whorl, members - sepals. Green, leaf like, protect flower in bud stage. Gamosepalous (united) or polysepalous (free). B) Corolla - Petals, bright coloured to attract insects. Gamopetalous (united) polypetalous (free). May be tubular, bell shape, funnel shape, wheel shape. Aestivation - Arrangement of sepals & petals in floral bud with respect to other members of same whorl. 1) Valvate - Sepals and petals just touch each other. E.g: Calotropis. 2) Twisted - One margin of appendage overlaps the next & so on. E.g: China rose, lady finger, cotton. 46 Morphology of Flowering Plants 3) Imbricate - Margins overlap one another but not in particular direction (1 out, 1 in, 3 out in). E.g: Cassia, gulmohar. 4) Vexillary - Large (vexillum or standard) overlaps 2 lateral petals (wings) which overlap 2 smallest petals (Keels). E.g: Peas & bean (Papilionaceous). C) Androecium - Composed of stamen. (Male reproductive organ). Consist of stalk/filament & anther. Anther- bilobed, each with 2 chamber, pollen sacs. Sterile stamen - Staminode. Stamens attached to petals - epipetalous. E.g: Brinjal. Stamens attached to perianth - epiphyllous.E.g: Lily. May be united or free. United into 1 bunch - monoadelphous. E.g: China rose. United into 2 bunch - E.g: Diadelphous, pea. United into more than 2 bunch - Polyadelphous. E.g: Citrus. Variation in length of filament. E.g: Salvia, mustard. D) Gynoecium - Female reproductive part, 1 or more carpels. Stigma - Recepts pollen grain. Style - Connects to ovary, elongated tube. Ovary - Enlarged basal part. Each ovary has 1 or more ovules attached to placenta. Carpels may be free - apocarpous. E.g: Lotus & rose. Carpels may be fused - syncarpous. E.g: Mustard & tomato. Placentation - Arrangement of ovules within ovary. 1) Marginal - Placenta forms ridge along ventral suture of ovary & ovules form 2 rows. E.g: Pea. 2) Axile - Axial placenta & ovules attached to multilocular ovary. E.g: China rose, lemon, tomato. 3) Parietal - Ovules on inner wall of ovary, (1 chambered but becomes 2 due to false septum). E.g: Mustard & Argemone. 4) Free central - Ovules on central axis & septa is absent. E.g: Dianthus & Primrose. 47 Morphology of Flowering Plants 5) Basal - Placenta at base of ovary & single ovule is attached to it. E.g: Sunflower, marigold. The Fruit : Mature ripened ovary developed after fertilisation. Parthenocarpic – Fruit developed without fertilisation. They are seedless fruits. E.g: Banana. Fruit wall/pericarp - Dry or fleshy. → Outer epicarp, middle mesocarp & inner endocarp. Mango & Coconut - Fruit is drupe (develop from monocarpellary superior ovaries & 1 seeded). Mango - thin epicarp & fleshy mesocarp, stony endocarp. Coconut - fibrous mesocarp, hard endocarp. 48 Morphology of Flowering Plants Edible part of mango is fleshy mesocarp. Edible part of coconut is endosperm. The Seed: Ovules after fertilisation, seed coat + embryo. Embryo - Radicle, embryonal axis, 1 or 2 cotyledons. 1) Dicot seed – E.g: Gram, pea, bean. Seed coat - Outer testa, inner tegmen. Hilum - Scar on seed coat through which developing seeds attached to fruit. Small pore above it – micropyle. 2 fleshy, full of reserve food cotyledons. Non - endospermic seed - endosperm absent in mature seed. At 2 ends of embryonal axis are radicle & plumule. 2) Monocot seed - E.g: Wheat, maize, castor. Endospermic, orchid – non - endospermic (Exception). In maize - membranous seat coat fused with fruit wall. Aleurone layer - Proteinaceous layer. Small embryo in a groove at one end. Large, shield shaped cotyledon – scutellum. Short axis with plumule & radicle enclosed in coleoptile & coleorhiza. 49 Morphology of Flowering Plants Semi Technical Description of a typical flowering plant: K - Calyx, C - Corolla, P - Perianth, A - Androecium. G - Gynoecium, G - Superior ovary, Ḡ - Inferior ovary. % - Zygomorphic, (--) - Fusion, Adhesion. * Position of mother axis with respect to flower - dot on top. 1) Fabaceae - Papilionoideae (sub family of Leguminosae) tree, shrubs, herbs, root. Stem - Erect/climber. Leaves - Alternate, pinnately, pulvinate leaf base, reticulate. 50 Morphology of Flowering Plants Inflorescence – Racemose. Flower - Bisexual, zygomorphic. Calyx - 5, gamosepalous, valvate/imbricate. Corolla - 5, polypetalous, vexillary. Androecium - 10, diadelphous, dithecous anther. Gynoecium - Ovary superior, monocapellary, unilocular. Fruit - Legume, seed, non- endospermic. Floral Formula - Economic Importance - Pulses (gram, arhar, sem, moong, soyabean), dye (indigofera), oil (soyabean, groundnut), fibres (sunhemp), medicine (muliathi), fodder (Sesbania, Trifolium), ornamental (lupin, sweet Pea). 2) Solanaceae - Potato family. Herbs, shrubs, small trees. Stem - Aerial, erect, branched, cylindrical, solid/hollow/hairy. Leaves - Alternate, simple, reticulate. Inflorescence - Cymose, solitary. Flower - Bisexual, actinomorphic. Calyx - 5, united, valvate. Corolla - 5, united, valvate. Androecium - 5, epipetalous. Gynoecium - Bicarpellary, ovary superior, axile, bilocular, syncarpous. Fruit - Berry/capsule. Seeds - Many endospermous. Floral formula – Economic Importance - Source of food (tomato, brinjal, potato), spice (chilli), fumigatory (tobacco), ornamental (petunia), medicine (Ashwagandha, Belladonna). 51 Morphology of Flowering Plants 3) Liliaceae- lily family. Herbs with underground bulbs/rhizomes. Leaves - Alternate, parallel. Inflorescence - Solitary, cymose. Flower - Bisexual, actinomorphic. Perianth - 6 tepals (3+3), valvate. Androecium - 6, (3+3), epitepalous/epiphyllous. Gynoecium - Tricarpellary, syncarpous, ovary superior, axile trilocular. Fruit - Capsule, rarely berry. Seed - Endospermous. Floral formula - Economic importance - Ornamentals (tulip, gloriosa), medicine (Aloe), vegetables (Asparagus, bulb of onion and garlic is also edible), colchicine (causes polyploidy). 52 Anatomy of Flowering Plants Anatomy – Study of internal structure. The tissues – Group of cells having common origin performing common function. Meristematic tissues: Meristems - Region of active cell division. A) Apical meristems - Tip of roots & shoots, produce primary tissues. B) Intercalary meristems - Between mature tissues. Occur in grass & regenerate parts removed by grazing herbivores. Apical & intercalary meristem constitute primary meristem as appear in early life. Axillary bud - Cell left behind from shoot apical meristem during formation of leaves & elongation of stem, present in axils of leaves & form branch or flower. C) Lateral meristem - It constitute secondary meristem. Mature regions of roots & shoots. E.g: Woody axis. Cylindrical, produce secondary tissues. E.g: Fascicular vascular cambium, interfascicular Cambium & cork cambium. Permanent tissues: New cells become structurally & functionally specialised & lose ability to divide. All cells similar in structure & function - simple tissues. 1) Simple tissues - One type of cells. Parenchyma - Major, isodiametric, may be spherical, oval, round, polygonal, thin cellulosic walls, small intercellular space, perform photosynthesis, storage, secretion. Collenchyma - Below epidermis either as homogenous layer or patches, thick cornered wall due to cellulose, hemicellulose & pectin, may be oval, spherical or polygonal, mechanical support, spaces absent, assimilate food if contain chloroplast. Sclerenchyma - Long, narrow cells with thick, lignified walls, protoplast absent, dead, mechanical support. i) Fibres - Thick walled, elongated, pointed. ii) Sclereids - Spherical/oval/cylindrical, thickened dead cells, narrow lumen, fruit walls of nuts, pulp of guava, pear & sapota, seed coat of legumes & tea leaves. 53 Anatomy of Flowering Plants 2) Complex tissues - Different types of cells perform single function. i) Xylem - Conduct water & minerals from roots to stem & leaves. Tracheids - Elongated, tube like, thick lignified walls, tapering ends, dead, without protoplasm. Vessels - Absent in gymnosperm, cylindrical tube made of vessel members, lignified walls, central cavity, dead, interconnected through perforation, characteristic feature. 54 Anatomy of Flowering Plants Fibres - Highly thickened walls, may be septate/aseptate. Parenchyma - Thin walled, living, store food in form of starch or fat or tannins, radial conduction of water by ray parenchymatous cells. Tracheids & vessels are main water transporting elements. Protoxylem - First formed primary xylem elements. Metaxylem - Later formed primary xylem. Endarch - Protoxylem towards centre & metaxylem towards periphery. E.g: Stem. Exarch - Protoxylem towards periphery & metaxylem towards centre. E.g: Roots. ii) Phloem - Transport food material from leaves to other parts. Sieve tube elements - Long, tube like, perforated ends to form sieve plate, lacks nucleus when mature, controlled by nucleus of companion cells, absent in gymnosperm. Companion cells - Parenchymatous, maintain pressure gradient in sieve tubes, absent in gymnosperms, connected to sieve tubes by pit field. Parenchyma - Elongated, tapering, cylindrical, dense cytoplasm and nucleus, pits for connection, store food & resin, mucilage, latex, absent in monocots. Fibres - Sclerenchymatous, elongated, unbranched, pointed, thick wall, absent in primary phloem, fibres of jute, flax & hemp for commercial purpose. Protophloem - First formed primary phloem, narrow tubes. Metaphloem - Later formed phloem, bigger sieve tubes. The tissue system - 1) Epidermal tissue system - Outermost covering. Epidermis - Outermost layer, elongated, compact, single layered, parenchymatous, large vacuole, covered with waxy thick layer - cuticle (absent in roots) prevent water loss. Stomata – Regulate transpiration & gaseous exchange, 2 bean shape guard cell (dumbell shape in grasses), outer walls of guard cell are thin & inner are thick, possess chloroplast & regulate opening & closing of stomata. Subsidiary cells - Cells of epidermis close to guard cell become specialised in shape & size. Stomatal apparatus - Stomatal aperture + subsidiary cell + guard cell. Epidermal appendages - Bear no. of hairs. Root hair - Unicellular, absorb water & mineral. Trichomes - Multicellular, branched/unbranched, prevent water loss & helps in protection. 55 Anatomy of Flowering Plants 2) Ground Tissue System - All tissue except epidermis & vascular. Parenchymatous - Cortex, pericycle, pith, medullary rays, primary roots of stems. Collenchyma - Hypodermis of dicot stem. Sclerenchyma - Hypodermis of monocot stem, pericycle. Mesophyll - Thin walled chloroplast containing cells in leaves. 3) Vascular Tissue System - Xylem + Phloem + Cambium (if present). Radial - Vascular tissue in alternate manner along different radii. E.g: Roots. Conjoint - Vascular tissue along same radius of vascular bundle. E.g: Stem & leaves. Close - No cambium, no secondary growth. E.g: Monocots. Open - Have cambium, show secondary growth. E.g: Dicots. Anatomy of Dicot & Monocot Plants – 1) Dicot Root: Epiblema - Outermost layer, root hairs. Cortex - Thin wall parenchymatous cells, innermost layer - endodermis, single layer barrel shaped cell (no space, tangential & radial walls have suberin (water impermeable), waxy in form of casparian strips. Pericycle - Few layer thick walled parenchyma. Pith - Small, undeveloped. Vascular bundle – 2 - 4 xylem & phloem, exarch. Conjuctive tissue - Parenchymatous cells between xylem & phloem. Stele - Tissues on innerside of endodermis. E.g: Pericycle, pith, vascular bundle. 56 Anatomy of Flowering Plants 2) Monocot Root: Similar to dicot but has more than 6 xylem bundles & phloem (polyarch). Pith is large & well developed. 3) Dicot stem: Epidermis - Outermost protective layer, thick cuticle, trichomes. Cortex - Between epidermis & pericycle. Hypodermis - Outer, collenchymatous, mechanical strength. Cortical - Round thin parenchymatous cells, space present. Endodermis - Innermost, rich in starch grain - starch sheath. Pericycle - Inner side of endodermis, sclerenchymatous. Medullary rays - Parenchymatous between vascular bundle. Vascular bundle - Ring arrangement, conjoint open, endarch protoxylem, 8-15 in number. Pith - Round parenchymatous cells in centre. 4) Monocot stem: Similar to dicot stem but scattered vascular bundles. Sclerenchymatous, hypodermis, phloem parenchyma absent. Conjoint closed vascular bundles. 57 Anatomy of Flowering Plants 5) Dorsiventral (Dicotyledonous) leaf: Epidermis - Covers upper (adaxial) & lower (abaxial), cuticle, abaxial has more stomata. Mesophyll - Tissue between upper & lower epidermis, parenchyma. Palisade parenchyma - Adaxial, elongated, parallel, vertical cells. Spongy parenchyma - Oval/round, loose, below palisade. Vascular system - Vascular bundles in veins & midrib, surrounded by thick walled bundle sheath cells. 6) Isobilateral (Monocotyledonous) Leaf: Stomata are equal on both surface. Mesophyll isn't differentiated to spongy & palisade parenchyma. Bulliform cells - Adaxial cells modify into large, empty, colourless, cells, become turgid on absorbing water, become flaccid due to water loss so curl leaf to minimise water loss. E.g: Grasses. 58 Anatomy of Flowering Plants Secondary Growth – Increase in girth. 2 lateral meristem - vascular cambium & cork cambium. 1) Vascular Cambium: Meristematic layer responsible for cutting off vascular tissues. a) Formation of cambial ring: Intrafascicular - Between primary xylem & primary phloem. Interfascicular - By cells of medullary rays adjoining intrafascicular cambium, continuous ring, meristematic. b) Activity of cambial ring: Cambial ring becomes active, cut off new cells. Secondary xylem - Cells cut off towards pith Secondary phloem - Cells cut off towards periphery. Xylem is more as ring is more active on inner side. Primary & secondary phloem crush due to formation of secondary xylem. Secondary medullary rays - Cambium forms narrow band of parenchyma passing through secondary xylem & phloem in radial directions. c) Spring wood & autumn wood: Spring wood - Early wood, in spring, cambium is more active, so more xylem with wider cavities, light, low density. 59 Anatomy of Flowering Plants Autumn wood - Late wood, in autumn, cambium is less active, few xylem with narrow cavities, dark, high density. Annual ring - 2 wood appear as alternate concentric rings, gives age of tree. d) Heartwood & Sapwood: In old trees, secondary xylem is brown due to tannins, oils, resin, gums, these make it hard, durable, resistant to microbial attack. Heartwood - Dead elements with lignified walls, doesn't conduct water, mechanical support, central region of secondary xylem, also called duramen. Sapwood - Peripheral region of secondary xylem, lighter in colour, conduct water & mineral, also called alburnum. 2) Cork cambium: As stem increases in girth, cortical & epidermis layers break, needs to be replaced, so cork cambium develops. Phellogen (cork cambium) - Thick, narrow thin walled rectangular cells, cut off cells on both sides. Phellem (cork) - Outer cells differentiate to phellem. Phelloderm (secondary cortex) - Inner cell differentiate to phelloderm. Periderm - Phellogen + Phellem + Phelloderm. Cells of secondary cortex are parenchymatous & cork is impervious to water. Bark - Due to cork cambium, pressure builds, phellogen die & slough off, tissue exterior to vascular cambium. Formed early in season - early/soft bark. Formed late in season - late/hard bark. Lenticels - Sometimes phellogen cuts closely arranged parenchymatous cells instead of cork cells, which rupture forming lens shaped opening, permit gaseous exchange, occur in woody trees. 60 Anatomy of Flowering Plants 3) Secondary Growth in Roots: Vascular cambium is completely secondary, originate from tissue below phloem, portion of pericycle tissue, above protoxylem forming complete, continuous wavy ring. * Secondary growth also occur in stems and roots of gymnosperms. 61 Structural Organisation In Animals Tissue: Group of similar cells having similar origin and performing specific function. Cells → Tissue → Organ → Organ system: Division of labour. Animal Tissue: 1) Epithelial Tissue - Has free surface either facing fluid or outside environment. Compactly packed with little space. a) Simple: Single layer of cells. Squamous: Single thin layer flattened cells, irregular boundary, walls of blood vessel, air sacs of lungs. Cuboidal: Cube like cells, ducts of glands, secretion & absorption tubular part of nephron. E.g: Proximal convulated tubule. Columnar: Tall & slender cells, basal nuclei, lining of stomach & intestine, secretion & absorption. Ciliated: Bears cilia, move particles/mucus in specific direction, bronchioles & fallopian tubes. Glandular: Secretion. Unicellular: Isolated cell. E.g: Goblet cell. Multicellular: Cluster of cell. E.g: Salivary gland. b) Compound epithelium: 2 or more cell layers, protective, covers dry surface, moist surface of buccal cavity, pharynx, duct of salivary glands, pancreatic ducts. On the basis of mode of pouring of secretion: Exocrine - Secrete mucus, saliva, earwax, oil, milk through ducts. Endocrine - Don't have ducts, secrete hormones directly into fluid, blood. Cell junctions: Tight: Stop substances from leaking. 62 Structural Organisation In Animals Adhering: Cementing to keep cells together. Gap: Communicate with each other, transfer of ions/molecules. 2) Connective Tissues: Most abundant, widely distributed. Link & support other tissues. Secrete fibres of protein – Collegen/elastin except blood which provide strength, elasticity & flexibility. Secrete modified polysacharides, act as matrix. a) Loose connective tissue: Cells & fibres loosely arranged. Areolar: Beneath skin, framework, contain fibroblast (cells that produce & secrete fibres), macrophages & mast cells, lymphocytes, plasma cells. Adipose: Beneath skin, store fats, nutrients which aren't immediately converted to fat. b) Dense connective tissue: Fibres are compactly packed. Dense regular: Collegen fibre in rows between parallel bundles of fibres. Tendons: Attach skeletal muscles to bone. 63 Structural Organisation In Animals Ligaments: Attach one bone to another. Dense irregular: Fibres oriented differently, present in skin. c) Specialised connective tissue: Cartilage: Solid, pliable, resist compression, chondrocytes in small cavity, most of cartilage in vertebrate embryos are replaced by bones in adults, tip of nose, outer ear joint, limbs & hands, between adjacent bones of vertebral column. Bones: Hard, non-pliable, rich in calcium salts & collagen fibres, strength, structural framework of body, osteocytes are present in lacunae (space), bring movement with muscles. E.g: Limb bones - long, weight bearing, bone marrow - RBC production. Blood: Fluid connective tissue, has plasma, RBC, WBC, platelet, transport substances. 3) Muscle Tissue - Long, cylindrical fibres in parallel arrays. Fibres are composed of myofibrils, contract & relax to adjust changes in environment, movement. 64 Structural Organisation In Animals Skeletal - Attached to skeletal bones. E.g: Biceps. Smooth - Taper at both ends (fusiform), no striation, involuntary. E.g: Blood vessel, stomach, intestine. Cardiac - Contractile tissue in heart, communication junction (intercalated disc) allow cell to contract as a unit. 4) Neural Tissue: Body's responsiveness to changing environment. Neurons are exciatable. Neuroglial cells: Protect & support neurons, more than half volume of neural tissue. Neuron stimulated → Electrical disturbance → Swift through plasma membrane → Disturbance at nerve ending → Stimulation/inhibition of adjacent neuron. Earthworm: Pheretima & Lumbricus. Reddish brown terrestrial invertebrate in upper layer of soil. Live in burrows by boring & swallowing. Can be traced by faecal deposits - Worm casting. Morphology: Long cylindrical body with 100 - 120 similar metameres. Dorsal: Dark median mid dorsal line (dorsal blood vessel). Ventral: Genital opening. 65 Structural Organisation In Animals Anterior end: Mouth & prostomium (cover mouth, force open cracks in soil, sensory). Peristomium: First body segment having mouth. Clitellum: Dark band of glandular tissue (14 - 16 segments). Body is divisible into preclitellar, clitellar & postclitellar segement. 4 pair of spermathecal aperture on ventro - lateral side. (5th - 9th segment). Female genital pore - Mid ventral line of 14th segment. Male genital pore – Ventro - lateral side of 18th segment. Nephridiopores open on surface. Setae - S - shaped embedded in epidermal pits made of chitin, locomotion, can be extended/retracted, present in each segment except 1st , last & clitellum. Anatomy: Outermost thin non - cellular cuticle → epidermis 2 muscle layer (circular & longitudinal) → innermost coelomic epithelium. Epidermis → Columnar epithelium (secretory gland cells). a) Alimentary Canal - Straight tube between 1st to last segment. Terminal mouth open to buccal cavity (1 - 3 segments) then to pharynx. Oesophagus (5 - 7 segment) continue to gizzard (8 - 9 segments) which help in grinding soil particles & decaying leaves. Stomach (9 - 14) - neutralise humic acid by calciferous gland. Intestine (15th - last segment) - short conical intestinal caecae on 26th segment. Typhlosole - Internal median fold of dorsal wall, increase absorption area, characteristic feature, from 26th segment to last except 23 – 25th. Open to exterior round aperture - anus. Digestive enzyme break complex food, simple molecules are absorbed. b) Circulatory system – Closed (vessel + capillaries + heart). Blood confined to heart and blood vessel, flow in 1 direction. 66 Structural Organisation In Animals Blood glands – 4th, 5th and 6th segment produce blood cells and haemoglobin. Phagocytic blood cells, smaller blood vessel supply gut, nerve cord etc. c) Respiratory system - Lack breathing devices, through moist surface. d) Excretory system - By coiled tubules (nephridia). 3 types of nephridia - Septal - Both side of intersegmental septa (15th to last segment to intestine). Integumentary - Lining of body wall (segment 3rd to last). Pharyngeal - 3 paired tufts (4th, 5th & 6th segment) Similar in structure, regulate volume & composition of body fluid, starts as funnel collecting fluid from coelomic chamber. e) Nervous system - Represented by ganglia on ventral paired nerve cord. Anterior, bifurcating nerve cord (3rd & 4th segment) encircling pharynx & join ganglia dorsally to form nerve ring. Cerebral ganglia + Nerves - sensory input & muscular response. f) Sensory system - No eyes. Has light & touch sensitive organs on anterior to distinguish intensities & vibrations. Chemoreceptor (taste receptors) to react to chemical stimuli. g) Reproduction system - Hermaphrodite (bisexual). Testes - 2 pairs (10th & 11th segment), vasa deferentia run upto 18th segment to join prostatic duct. 67 Structural Organisation In Animals Accessory glands - 2 pairs (17th & 19th segment). Common prostate & spermatic (vasa deferentia) open to exterior by male genital pore on 18th segment. 4 pair of spermathecae – 6th to 9th segment (receive & store spermatozoa). Ovary - 1 pair at septa of 12th & 13th segment. Ovarian funnel beneath ovary open to oviduct which open on ventral side as single median genital pore on 14th segment. h) Cross fertilisation - Due to large distance between male & female pores. 2 worms mate juxtaposing opposite gonadal opening exchanging spermatophores. Mature sperm, egg cells & nutritive fluid are deposited in cocoons produced by gland cells of clitellum. Ova are fertilised by sperm cell within cocoon which slips off worm & deposited on soil. Cocoon holds embryo & after 3 weeks, each cocoon produce 2 - 20 baby worms (average 4). Direct development (no larva). Friends of farmers – Make burrows in soil & make it porous which help in respiration & penetration of developing plant roots. Process of increasing fertility of soil by earthworm – vermicomposting. Used as bait in fishing. Cockroach – Brown/black, can be yellow, red in other region. 1/4 to 3 inches (0.6 - 7.6 cm) in size, long antennae, serious pests. Flat - extension of upper body conceals head, noctural omnivores. Found in damp place, vectors of several diseases. No economic importance, many species are wild. Morphology – Periplaneta Americana - Adult, 34 - 53 mm, wings extend beyond abdomen tip in males. 68 Structural Organisation In Animals Segmented body divisible into head, thorax & abdomen. Chitinous exoskeleton with hardened plates - sclerites (tergites dorsally & sternites ventrally) joined by thin flexible articular membrane. Head - Triangular, 90° to body axis, fusion of 6 segments, flexible neck, bear compound eyes. Thread like antennae from sockets in front of eyes, which has sensory receptors. Anterior mouth - Biting & chewing. Mouthparts - Labrum (upper lip), pair of mandibles, pair of maxillae, Labium (lower lip), hypopharynx (tongue, median lobe). Thorax - Prothorax, mesothorax & metathorax. Head is connected to thorax by neck (short extension of prothorax). Each thoracic segment bears pair of legs. 1st pair of wings from mesothorax, second from metathorax. Tegmina - Forewings (mesothoracic), opaque, leathery, cover hind wings at rest, also called elytra. Hind wings - Transparent, membranous, for flight. Abdomen in male & female has 10 segments. Females -7th sternum (boat shape) with 8th & 9th sterna form genital pouch (anterior part has gonopore, collateral gland & spermathecal pores). 69 Structural Organisation In Animals Males - Genital pouch at hind end of abdomen, dorsally by 9th & 10th terga & ventrally by 9th sternum, contains dorsal anus, genital pore, gonopophysis, bear short thread like anal style (absent in female). In both sex, 10th segment bear jointed filamentous structure - Anal cerci. Anatomy: a) Alimentary canal: Foregut + Midgut + Hindgut Mouth opens to tubular pharynx, leading to narrow tubular oesophagus, which open into sac like crop (food storing), then gizzard or proventriculus (grinding). Thick circular muscles on outer & thick cuticle on inner forming 6 chitinous plate called teeth. Foregut is lined by cuticle. 6 - 8 blind tubule (hepatic/gastric caeca) at junction of foregut & midgut secrete digestive juice. 100 - 150 yellow colour thin Malpighian tubule at junction of midgut & hindgut to remove waste from haemolymph. Hindgut is broader than midgut & differentiated into ileum, colon, rectum. Rectum opens through anus. b) Circulatory system: Open Poorly developed blood vessel open into haemocoel. Haemolymph - Colourless plasma + Haemocytes. Visceral organs in haemocoel are bathed in haemolymph. 70 Structural Organisation In Animals Heart is elongated tube like along line of thorax & abdomen, differentiated into funnel shaped chambers with ostia on either side. Blood from sinuses enter heart & pumped to sinuses again. c) Respiratory system: Network of trachea open through 10 pairs of holes – spiracles. Thin branching tubes (tracheal tubes) carry oxygen to all parts. Gaseous exchange at tracheoles by diffusion. d) Excretory system: Uricotelic, by malpighian tubules. Lined by glandular & ciliated epithelium. Absorb nitrogenous waste & convert them into uric acid. Fat body, nephrocyte & uricose gland also help in excretion. e) Nervous system: Fused segmentally arranged ganglia joined by connectives. 3 ganglia in thorax, 6 in abdomen. Head holds a bit of nervous system while rest is along ventral part. So, if head is cut off, it may survive for 1 week. Brain - supra oesophageal ganglion which supply nerve to antennae & compound eyes (dorsal surface of head). Each eye 2000 hexagonal ommatidia (several images) -mosaic vision (high sensitivity less resolution), common during night. Sense organs - Antennae, eyes, maxillary palps, labial palp, anal cerci. f) Reproductive system: Dioecious, well developed sex. Male - Pair of testes one on each side in 4 – 6th abdominal segments, from which arise vas deferens, open into ejaculatory duct through seminal vesicle, open into male gonopore to anus, external genitilia - male gonapophysis/phallomere (chitinous), sperms stored in 71 Structural Organisation In Animals seminal vesicle are glued in bundle - Spermatophores, pair of spermatheca (6th segment) open into genital chamber. Accessory gland - Mushroom shaped in 6th -7th abdominal segment. Female - 2 large ovaries (2nd -6th segment), each ovary is group of 8 ovarioles, oviduct of each ovary unite into single median oviduct (vagina) which opens to genital chamber. g) Cross fertilisation: Sperms are transferred through spermatophore. Fertilised eggs are encased in capsule - oothecae (Reddish to blackish, brown, 8mm long), dropped in crack with high humidity. Female produce 9-10 oothecae (14-16 eggs each). P. Americana - Paurometabolous (development through nymphal stage), nymph is similar to adult, moult about 13 times. Next to nymphal stage has wing pads but only adults have wings. Frogs: Amphibian, most common - Rana tigrina, poikilothermous. Ability to hide colour (camouflage), protective colouration - mimicry. Deep burrows in extreme cold or extreme hot. Aestivation - Summer sleep, Hibernation - Winter sleep. Morphology – Smooth & slippery skin due to mucus. Olive green on dorsal side with irregular spots & pale yellow on ventral side. Never drinks water, only absorbs it through skin. Neck & tail absent, body divisible into head & trunk. Nostrils present, bulged eyes with nictitating membrane (protects them in water), tympanum receive sound signals. Fore limbs & hind limbs for leaping, burrowing, swimming. Hind limbs - 5 digits, larger, more muscular. Fore limbs - 4 digits. Webbed feet for swimming, sexual dimorphism. Male are distinguished by sound producing vocal sacs &copulatory pad on 1st digit of fore limb. Anatomy – a) Alimentary canal - Short as they are carnivores, reduced intestine. Mouth opens to buccal cavity which lead to oesophagus through pharynx, which opens to to stomach which constitute intestine, rectum & finally opens outside by cloaca. Liver secrete bile stored in gall bladder, pancreas secrete pancreatic juice. Food is captured by bilobed tongue, digestion of food by HCl & gastric juices, partially digested food - chyme is passed to duodenum. 72 Structural Organisation In Animals Duodenum receive bile from gall bladder & pancreatic juice from pancreas through common bile duct. Bile emulsifies fat & pancreatic juice digest carbohydrate & protein. Digested food is absorbed by finger like folds in intestine - villi & microvilli, undigested waste to rectum & passed by cloaca. b) Respiratory system: Both on land & water. Water - cutaneous, by skin through diffusion. Land - skin & lungs (pulmonary) - pair of elongated, pink coloured sac like lungs in upper part of thorax. During aestivation & hibernation - gaseous exchange by skin. c) Circulatory system: Well developed, closed with lymphatic system. Lymphatic system – lymph, lymph channel, lymph nodes. Involves heart, blood vessels & blood. Heart (3 chamber) is muscular in upper part of body cavity, covered by pericardium. Triangular structure - Sinus venosis join right atrium, receive blood from major veins – vena cava, ventricles open into conus arteriosus. Blood from heart to all body parts is carried by arteries & veins collect - blood from body parts to heart. Special venous connection between liver & intestine (hepatic) as well as kidney & lower parts (renal portal). Blood - Plasma + Cells (RBC +WBC/Leucocyte + Platelets). RBC - nucleated, haemoglobin, carries nutrient, water etc. Lymph lacks proteins & RBCs. d) Excretory system: Well developed, excrete urea – Ureotelic. Pair of kidney, ureters, cloaca, urinary bladder. Kidney - compact, red, bean like structure, has several structural & functional unit - uriniferous tubules (nephrons). In males, 2 ureters emerge from kidney, act as urinogenital duct which opens into cloaca. In females, ureters & oviduct open separately in cloaca. Thin walled urinary bladder to rectum which opens to cloaca. Excretory waste by blood to kidney where its separated & excreted. 73 Structural Organisation In Animals e) Nervous system: Highly evolved. Control & cordination - neural + endocrine. Endocrine glands - pituitary, thyroid, parathyroid, thymus, pineal, pancreatic, adrenal & gonads. Nervous system - Central nervous system (brain + spinal cord), Peripheral nervous system (cranial+ spinal nerve) & autonomic nervous system (sympathetic & parasympathetic). 10 pairs of cranial nerves, brain is enclosed in brain box (cranium). Forebrain - Olfactory lobes, paired cerebral hemisphere, unpaired diencephalon. Midbrain - Paired optic lobes. Hindbrain - Cerebellum & medulla oblongata which passes through foramen magnum & to spinal cord. f) Sensory organs: Cellular aggregates except eyes & internal ears. Organs of touch (sensory papillae), taste (taste buds), smell (nasal epithelium), vision (eyes), hearing (tympanum). Eyes - Spherical, in orbit of skull, simple. Ear - External ear absent, tympanum present, hearing & balancing. g) Reproductive system: Well organised. Male - Pair of yellowish ovoid testes adhered to upper part of kidney by mesorchium, 10 - 12 vasa efferentia from testes enter kidney & open into Bidder's canal, joins urinogential duct & opens into cloaca (small median chamber passing faecal matter, urine & sperms). Female - Pair of ovaries near kidney (no functional connection between two), pair of oviduct from ovary opens to cloaca, mature female lay 2500 - 3000 ova at a time. External fertilisation in water, indirect development. Larval stage - tadpole (metamorphosis to form adult). Beneficial: Eat insects & protect crop. Ecological balance, important link of food chain & food web. Muscular legs are eaten by man. 74 Structural Organisation In Animals 75 Cell: The Unit of Life Cell: Fundamental structural & functional unit of life. Discovery of living cell – Anton von Leuwenhoek Discovery of nucleus – Robert Brown Cell Theory: By German Botanist Matthias Schleiden & british zoologist Theodore Schwann. Schleiden: Plants are composed of different kind of cells. Schwann: Presence of plasma membrane. But it didn't explained how new cells were formed. Rudolf Virchow: Explained that cell divided & new cells are formed from pre-existing cells (omnis cellula-e-cellula). Final theory: All organism are composed of cells & new cells arise from pre-existing cells. Cell: Dense membrane bound structure: Nucleus. Semi fluid matrix: Cytoplasm (main arena of cellular activities). Membrane bound distinct-structures: Organelles. Animals: Centrosome (cell division). Mycoplasma: 0.3 µm (smallest) to 3-5 µm bacteria Largest isolated single cell: Egg of ostrich Human red blood cell: 7µm diameter Longest cell: Nerve cell. Prokaryotic cell: Lack membrance bound nucleus & cell-organelles. Eg: Bacteria, blue green algae, mycoplasma, PPLO (Pleuro Pneunomia like organisms) Small, multiply rapidly, no nuclear membrane. Bacteria can be bacillus (rod), coccus (spherical), vibrio (comma), spirillum (Spiral). Have cell wall except mycoplasma, naked genetic material. 76 Cell: The Unit of Life Genomic DNA + Small circular DNA (Plasmid), ribosomes present. Infoldings of cell membrane – mesosome, resistant to antibiotics. Cell Envelope & Modifications Outermost glycocalyx → cell wall → plasma membrane. Single protective unit. Glycocalyx as loose sheath – slime layer, as thick & tough layer – capsule. Cell wall prevent bursting & collapsing of bacterium, provide shape. Selectively permeable plasma membrane. Gram positive: Can be stained. Gram negative – can not be stained. Mesosomes: Membranous structure formed by extension of plasma membrane into cell, can be in form of vesicles, tubules & lamellae, help in cell wall formation, DNA replication, respiration, secretion, increase surface area. Cyanobacteria: Other membranous extensions into cytoplasm – chromatophore (contain Pigments). Thin filamentous extensions: Flagella if motile. Flagella: Filament, hook & basal body (longest- filament) Besides flagella, pili & fimbrae are surface structure (no motility) Pili: Elongated tubular structure made of protein. Fimbrae: Small bristle like fibres. They attach bacteria to rocks in stream & to host tissues. Ribosme: Protein synthesis. Prokaryotes – 15 nm - 20 nm in size, 2 subunit – 50 S & 30 S, together form 70 S. Eukaryote – 80 S ribosome made up of 60 S and 40 S sub units. Attach to single m RNA & form chain - polyribosome/polysome, which translate mRNA to protein. Inclusion bodies: Store reserve material in cytoplasm. Lie free in cytoplasm, not bounded by any membrane. Eg: Phosphate granules, cyanophycean granule, glycogen granules. Gas vacuoles: Blue green & purple & green photosynthetic bacteria. Eukaryotic cells: Membrane bound nucleus & cell organelles. Eg: Protists, plant, animals & fungi. 77 Cell: The Unit of Life Genetic material is organised into chromosomes. Plant cells: Cell wall, plastid, large vacuole. Animal cells: Centriole (Centrosome). Cell Membrane: Phospholipid + Protein (bilayer) Lipids are arranged within membrane with polar head (hydrophilic) towards outer side & tail (hydrophobic) towards inner side. So, non polar tail is protected from aqueous environment. Membrane also contain cholestrol, phosphoglyceride (main lipid component), carbohydrate & protein. In human RBC: 52% protein 40% lipid, ratio varies in different cells. Peripheral protein: Lie on membrane surface. Integral protein: Partially or totally buried in membrane. Fluid Mosaic Model (1972) – Singer & Nicolson: Quasi fluid nature of lipid enable protein movement across membrane. Protein icebergs in a sea of liquid. Passive transport: Movement of molecules across membrane without energy. Neutral solute: By simple diffusion (high concentration to low concentration) Osmosis: Water movement across membrane by diffusion. 78 Cell: The Unit of Life Active transport: For polar molecules which can't cross non-polar layer, require carrier protein, energy, can be against concentration gradient, ATP utilised. Eg: Na+ - K+ Pump. Cell Wall: Non living, rigid Algae: Cell wall composed of cellulose, galactans, mannans, CaCo3 Plants: Cellulose, hemicellulose, pectin, protein. Provide shape, protection, interaction among cell, barrier to certain molecules. Primary wall: Capable of growth, diminishes as cell matures. Secondary wall: Inner side of cell ie. primary wall. Middle lamellae: Calcium pectate, holds cells together. Cell wall & middle lamellae are traversed by plasmodesmata which connects cytoplasm of cells. Endomembrane system: Golgi complex, vacuoles, endoplasmic reticulum, lysosomes. 1) Endoplasmic Reticulum: Network of tiny tubular structures in cytoplasm. 2 compartments: Luminal (inside ER) & extra Luminal (cytoplasm). RER: Rough endoplasmic reticulum, ribosomes on surface, secretion and synthesis of protein, continuous with outer membrane of nucleus. SER: Smooth endoplasmic reticulum, no ribosomes, smooth, synthesis of lipid, in animal cells synthesise steroidal hormones.