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W W W. S A K S H I . C O M / V I D YA / B H AV I T H A

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2

ANALYSIS

WEIGHTAGE

JUNIOR INTER

Frame your own time table

Prepared by

K.VANIMANOHAR

Senior Faculty, Sri Chaitanya Educational Institutions, Hyderabad.

From the academic year 2009, ranks have been given to science students based on their performance in Intermediate optional subjects with a weightage of 25% and EAMCET 75% to get into various professional courses of science stream such as Medical and Engineering. In this method, Biology is the subject that decides the rank in medical stream to some extent in Intermediate level and large extent in EAMCET. As Biology begins with Botany, it is important for the students to write biology well in EAMCET. When compared with Zoology and Chemistry, Botany paper is said to be tough but

not uncrackable. It is felt as tough because it was taking much time to answer the questions. When you look at the Botany section of 2009 EAMCET paper, 22 questions are of 3rd level (Multiple selection, Matching, Item groups, Assertion and Reason and Sequence type) and a three are concept based problems which consume much time to answer them. This was the reason for students feeling it as difficult one and it also reflected in deciding the rank. Keeping this in view, a thorough preparation in Botany is considered inevitable to all aspiring medical stream students of EAMCET 2010. General feelings of the students Can I be able to remember the numericals, names of plants and their characters. Whether this year will be easier or tough. How many will be my competitors. Not finding time to cover the subject in time.

LAST SIX YEARS CHAPTER WISE WEIGHTAGE

Chapter Name 1. Botany ­ Introduction 2. Vegetative Morphology 3. Reproductive Morphology 4. Reproduction in Angiosperms 5. Plant Taxonomy 6. Cell Biology 7. Internal Organization of Plants 8. Plant Ecology 9. Genetics 10. Plant Kingdom 11. Microbiology 12. Plant Physiology 13. Plants and Human Welfare

2004 1 2 1 4 5 2 4 1 5 2 7 4

2005 2006 1 1 3 2 3 2 3 4 3 3 2 1 3 4 1 2 5 4 2 2 6 9 5 4

2007 2008 2009 2 2 1 3 2 2 2 3 2 3 2 2 3 4 3 2 2 3 3 3 3 2 1 2 2 3 3 4 2 2 2 8 9 10 3 3 4

Analysis of types of Questions asked in Previous years of EAMCET Year 2004 2005 2006 2007 2008 2009 Average Direct Problems questions 18 3 18 1 17 5 18 8 2 9 6 14-15 3 A/R type 4 3 4 6 3 5 4 Matching 6 8 8 6 9 7 7-8 Item group 1 1 2 1 2 1 1-2 Sequence type 2 6 2 5 4 7 4-5 Multiple selection 6 3 2 4 12 5 5

Not able to answer the assertion and reason type questions well. Solutions Prepare tables for numericals, names of plants, unique features of plants in various topics in condensed form and look at them, try to recollect them at times. What ever may be the level of paper, it is common to all and you are not exception. With right preparation, you can convert the tough task as easier. This year only around 50,000 students are appearing for EAMCET from medical stream, which is far less than earlier 5 years. So competition is decreased and your chances of getting into medical stream enhanced.

Frame your own time table, giving equal importance to other subjects. Write a model test every day with a minimum of 20 questions with 10 moderate and 10 tough questions in the paper. It is preferable to take test from SAKSHI education website. Most important topics: Plant Physiology, Plant Taxonomy, Internal structure of plants, Plant Kingdom, Plants and Human Welfare. Hard topics: Usually metabolism of Physiology appears tobe difficult. It can be overcome by drawing various metabolic cycles. Memory tips: Prepare the lists of plants and their main features in the form of tables as given in Quick Reference (12th Page) and memorising them by covering one list at a time.

SUBJECT ANALYSIS

EXTERNAL MORPHOLOGY SYNOPSIS It is one of the important chapters. From all types 4-5 questions can be asked. So prepare tables for the topic and practice it. This is useful in solving some of the questions from Plant Ecology. Root It usually arises from Radicle of embryo and has root caps. Aquatic plants have root pockets. Dicots and most of the Gymnosperms have tap root system with acropetally arranged dissimilar lateral roots on the main root and adventitious root system is present in Monocots, Pteridophytes and some Gymnosperms and Dicots which arise as tufts usually at the basal region of stem Hydrilla has poorly developed roots whereas Utricularia and Wolffia lack roots. Stem Stem and its appendages are formed from plumule of Embryo. Tendrils (axillary bud of Passiflora, terminal buds of Cissus, Vitis), Hooks (axilary bud of Hugonia, terminal bud of Artabotrys),Thorns (terminal bud of Carissa, Axillary buds of Bougainvilleae, Punica, Duranta), Phylloclades (Opuntia, Cocoloba, Casuarina), Cladodes (Ruscus, Asparagus), Tuberous stems (Knol-Khol, Bulbophyllum-pseudo bulb) and Bulbils (floral buds of Agave, Globba, root buds of Oxalis, vegetative buds of Dioscorea) are Aerital stem modifications. Runners (Hydrocotyle, Lippia, Oxalis), Stolons (Nerium, Jasminum,Rosa), Suckers (Mentha, Chrysanthemum) and Offsets (Pistia, Eichhornia,Agave) are Sub-aerial stem modifications. Rhizome (Curcuma, Zingiber, Canna, Musa), Corm (Colocasia, Amorphophallus), Stem tuber (Solanum tuberosum, Helianthus tuberosus, Stachys tubifera) and Bulbs (tunicated bulb in Allium cepa, tunicated scaly bulb in Allium sativum, naked bulb in Lilium candidum) are Underground stem modifications. Leaf Leaves may be cauline (Cocos), radical (Allium) and ramal and may have deciduous (Michelia), persistant (Pisum, Lathyrus) or branched (Ipomoea quamoclit) stipules. Reticulate venation is common in Dicots, uncommon in Monocots (Smilax, Dioscorea) and may be Pinnate (Mangifera, Hibiscus), Palmate convergent (Zizyphus) or divergent (Passiflora, Gossypium, Cucurbita). Parallel venation is common in Monocots and uncommon in dicots (Caulophyllum, Eryngium) and can be Pinnate (Musa), Palmate convergent (Oryza sativa) or divergent (Borassus). Leaves types: These are unlobed simple (Annona, Psidium), Pinnately lobed (Brassica), Palmately lobed (Passiflora, Cucurbita, Ricinus), Unipinnate imparipinnate compound (Azadirachta), Paripinnate (Tamarindus), Bipinnate (Acacia, Delonix), Tripinnate (Moringa, Millingtonia), Decompound (Coriandrum), Unifoliate (Citrus), Bifoliate (Hardwickia), Trifoliate (Dolichos), Tetrafoliate (Marsilea), Pentafoliate (Gynandropsis) and Multifoliate (Ceiba pentandra). Phyllotaxy may be normal alternate (Hibiscus, Ficus), Leaf mosaic alternate (Carica, Acalypha), Opposite superposed (Quisqualis), Opposite decussate (Calotropis) and Whorled (Nerium). Leaf modifications (Refer quick review on 12th page) Inflorescence It may be terminal (Crotalaria, Croton), axillary (Dolichos) and Intercalary in position (Callistemon). Various Racemose Inflorescences (Acropetally arranged and centripetally opened flowers, unmodified terminal bud and indefinitely growing branched or unbranched peduncle) are Simple raceme (Crotalaria), Compound raceme (Mangifera, Yucca), Simple corymb (Gynandropsis, Cassia), Compound corymb (Brassica oleracea var. botrytis, Pyrus malus), Simple Umbel (Allium cepa), Compound Umbel (Coriandrum, Daucus), Simple spike (Achyranthes, Amaranthus), Compound Spike (Triticum, Oryza), Catkin (Casuarina, Acalypha), Simple Spadix (Colocasia), Compound Spadix (Cocos), Simple homogamous head with ray florets (Tagetus) or disc florets (Vernonia), Heterogamous head (Helianthus, Tridax) and Compound head (Echinops, Sphaeranthus). Solitary cyme (Axillary in Hibiscus, Terminal in Datura), Simple cyme or Cymule (Jasmine, Bougainvillea), Monochasial helicoid (Hamelia), Monochasial scorpioid (Heliotropium, Solanum), Dichasial cyme (Clerodendron, Ipomoea) and Polychasial cyme (Nerium) are various types of Cymose inflorescences (terminal bud modified as flower, definite growth of peduncle, basipetally arranged and centrifugally opened flowers). Verticillaster (Leucas, Leonotis), Cyathium (Euphorbia, Poinsettia)& Hypanthodium

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3

JUNIOR INTER

FLOWER

POLLINATION

In Angiosperms fertilization is..

(Ficus sp.) are different types of Special inflorescences that show some special modified features. Flower Based on distribution of uni and bisexual flowers, plalnts are classified into Dioecious (Borassus, Vallisneria), Monoecious (Cocos, Acalypha) and Polygamous (Mangifera, Polygonum) species. Floral symmetry on the basis of arrangement of floral parts is described as Acyclic (Magnolia), Hemicyclic (Annona, Polyalthia), Cyclic (Hibiscus, Datura), on basis of number of floral parts as Trimerous (Allium), Tetramerous (Brassica), Pentamerous (Hibiscus) and on basis of form and structure as Actinomorphic (Hibiscus), Zygomorphic (Dolichos, Ocimum) & Asymmetrical (Canna indica). Gynoecium position on the thalamus, classifies flowers into Hypogynous (Hibiscus, Datura), Perigynous (Tephrosia) and Epigynous (Tridax). On basis of Perianth nature and distribution, flowers are described as Achlmydeous (Euphorbia, Poinsettia), Monochlamydeous (Croton, Amaranthus), Homochlamydeous (Allium)&Heterochlamydeous(Datura,Hibiscus) Aestivation (arrangement of perianth lobes in bud condition) is Valvate in calyx of Hibiscus, Twisted in corolla of Datura and Hibiscus, Ascending imbricate in corolla of Caesalpiniaceae, Descending imbricate in corolla of Fabaceae and Quincuncial in the calyx of Ipomoea and Catharanthus. Calyx is Polysepalous in Annona, Gamosepalous in Hibiscus, Ephemeral in Argemone, Persistent Marcescent in Solanum and Persistent Acrescent in Physalis. Corolla may be polypetalous or gamopetalous Anthers of stamens can be described as Dithecous and Introrse as in Datura and Monothecous and Extrorse as in Hibiscus. Attachment of filament to the Anther is Basifixed in Datura, Dorsifixed in Hibiscus, Adnate in Nelumbo and Versatile in Oryza. Based on length of stamens, androecium is Didynamous with 2 short and 2 tall stamens in Ocimum, Tetradynamous with 4 tall inner and 2 short outer stamens in Brassica, Exerted in Acacia arabica and Inserted in Datura and Dolichos. Adhesion of Stamens may be Episepalous (Grevillea), Epipetalous (Datura), Epiphyllous (Asparagus) or Gynandrous (Gynostegium as in Calotropis). Anther dehiscence is Longitudinal in Datura, Transverse in Hibiscus, Valvular in Cassytha and Porous in Solanum. Gynoecium has 1 capel in Dolichos, 2 in Solanum, 3 in Allium, 4 in Oenothera, 5 in Hibiscus and many in Abutilon. Nelumbo and Michelia have Apocarpous gynoecium and Datura and Hibiscus have Syncarpous gynoecium. Junction of margins of same or adjacent carpels is called as Ventral suture and midribs of carpels as Dorsal suture. Ovary has 1 locule in Dolichos, 2 in Solanum, 3 in Allium, 4 in Ipomoea, 5 in Hibiscus and many in Abutilon. Placentation is Marginal in Dolichos, Parietal in Brassica and Cucurbita, Axile in Hibiscus, Free central in Dianthus, Supeficial in Nymphaea & Basal in Tridax and Helianthus. Style is Terminal in Hibiscus, Lateral in Mangifera and Gynobasic in Ocimum. Stigma secretes Sugary substances. Model Questions 1. [A]: All roots are positively geotropic. [R] : Respiratory roots are achlorophyllous. 1) A and R are correct and R is the correct explanation of A 2) A and R are correct but R is not the correct explanation of A 3) A is true but R is false 4) A is false but R is true 2. One of the following plants develops parasitic roots at its earlier stages and later becomes autotrophic 1) Rafflesia 2) Balanophora 3) Santalum album 4) Cuscuta 3. Study the following and identify the correct match Plant Function of its modified stem A. Carissa I) Photosynthesis B. Bougainvillea II) Storage of food C. Hugonia III) Protection D. Opuntia IV) Climbing V) Protection and climbing A B C D 1) III V IV I 2) III V II I 3) V III IV II 4) III IV I II 4. Arrange the following modified stems in a sequence of positively geotropic to negatively geotropic growth patterns i) Modified stem of Curcuma ii) Modified stem of Amorphophallus iii) Modified stem of Stachys tubifera iv) Modified stem of Mentha arvensis 1) ii, iv, i, iii 2) iii, i, iv, ii 3) iii, iv, i, ii 4) i, iii, iv, ii Key: 1) 4 ; 2) 3; 3) 1; 4) 2 Reproduction in Angiosperms From Introduction to Male gametophyte SYNOPSIS In this usually 2 to 3 questions are asked. Some of the questions are in the form of problems or inter topic related application type. or protogyny (Solanum, Scrophularia), Herkogamy (Hibiscus, Gloriosa), Heterostyly (combination of herkogamy and dichogamy) with diheterostyly (Primula, Oldenladia) and triheterostyly (Lythrum, Oxalis sp.), Self sterility (Abutilon, Passiflora, Orchids), Pollen Prepotency (Dolichos) and Sensitive stigmas (Mimulus, Martynia) are different contrivances for Cross Pollination. Homogamy (Caltha, Ranunculus - rain water helps in self pollination), Movement of floral parts (Argemone), Safety mechanism (Bisexual florets of Asteraceae) and Cleistogamy (Commelina, Streptocarpus) are contrivances for self pollination. The agents of cross pollination are wind (Anemophily-Oryza), water (Hydrophily - Epihydrophily in Vallisneria and Hypohydrophily in Zostera) and animals such as Insects (Entomophily in Cestrum), Birds (Ornithophily in Bignonia), Bats (Chiropteriphily in Kigelia pinnata) and Snails (Malacophily in Aroids). Fertilisation, Post fertilization changes, Seed structure and its germination Fusion of male and female gametes is called as Fertilization. Based on entry of pollen tube into the ovule, it is described as Porogamy (Ottelia, Hibiscus), Chalazogamy (Casuarina) and Mesogamy (Cucurbita). Pollen tube enters into the embryosac through one of the synergids and releases the 2 male gametes and vegetative nucleus into it. In Angiosperms fertilization is described as Double fertilization (Nawaschin in Fritillaria and Lilium) because 2 fertilizations are seen in the same embryosac. The 2 fertilizations are Syngamy and Triple fusion. Fusion of a male gamete with egg cell to form zygote is called as true fertilization or Syngamy or Zygotic fertilization (Strasburger in Polygonum). Fusion of 2nd male gamete with secondary nucleus or 2 polar nuclei to form 3n PEN is called as Triple fusion or Vegetative fertilization (Nawaschin in Lilium and Fritillaria). Endosperm formation is supressed in Orchidaceae and Podostemonaceae. Cocos, Datura and Ricinus have endospermic seeds and seeds of Cicer, Dolichos and Capsella are Non-endospermic. Unutilised nucellus present in the seed is called as Perisperm (Piperaceae, Nymphaeceae). Perisperm of coffee is edible. Aril (develops from funicle or Hilum) of Pithecalobium, Myristica (Mace) & Caruncle (develops from integument of micropylar region) of Ricinus communis are seed outgrowths. Formation of seedling from embryo of seed is called as seed germination. It is Epigeal in Dolichos and Cucurbita, Hypogeal in Maize and Pea and Viviparous in Rhizophora.

A dithecous anther has 4 microsporangia and each one has epidermis, endothecium with fibrous cellulosic thickenings, middle layers, nutritive tapetum and sporogenous tissue with Microspore mother cells that divide meiotically to form haploid microspores or pollen grains. A pollen grain has a wall with sporopollenin exine, pectocellulose intine and protoplast with haploid nucleus with dense protoplasm that develops into male gametophyte partially in the microsporangium (2-celled stage with generative and vegetative cells) and partially on the stigma (Pollen tube with vegetative nucleus and 2 male gametes). The male gametes are released into the embryosac. Pollen grains are polysiphonous in Malvaceae and Cucurbitaceae. Ovule to female gametophyte Ovules or megasporangia are present in the ovary which have a stalk (Funiculus) and body with nucellus, integuments (Unitegmic in gamopetalae, Bitegmic in Monocots and Polypetalae and Ategmic in Balanophora and Loranthus), micropyle and chalaza. The different types of ovules are Orthotropous with 0o curvature (Polygonum), Anatropous with 180o curvature (Asteraceae and many angiosperms), Hemitropous with 90o curvature (Primula, Ranunculus), Campylotropous with 90o curvature and micropyle towards funiculus (Brassicaceae, Fabaceae), Amphitropous with 160o curvature and horseshoe shaped embryosac (Alisma and Butomus) and Circinotropous with 360o curvature and elongated coiled funiculus as in Opuntia and Plumbago. During megasporogenesis a cell of Nucellus behaves as Megaspore mother cell, divides meiotically and forms 4 haploid megaspores to form 7-celled 8-nucleated embryosacs of Monosporic (Polygonum-discovered by Strasburgur), Bisporic (Allium sp.) and Tetrasporic (Fritillaria, Peparomia). Polygonum type of embryosac has egg apparatus with an egg cell or female gamete and 2 synergids(have filiform apparatus that guides the pollen tube into embryosac), a central cell with 2 polar nuclei that fuse and form diploid secondary nucleus & 3 haploid anti-podals. Pollination Dicliny (Vallisneria), Dichogamy with protandry (Gossypium, Helianthus, Clerodendron)

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4

JUNIOR INTER

PLANT TAXONOMY

CELL BIOLOGY

Cell wall was discovered by..?

Fruit False fruit is developed from non-ovarian part of the flower and it is seedless (Pedicel of Anacardium and Thalamus of Pyrus malus). True fruits are developed from ovary. They are Simple, Aggregate and Multiple types. Simple fruits are developed from syncarpous ovaries of a flower and may be Fleshy or Dry at maturity. Berry (Solanum, Lycopersicon, Musa, Phoenix), Pepo (Cucurbitaceae), Pome (Pyrus sp.), Hesperidium (Citrus sps.) and Drupe (Cocos, Mangifera) are fleshy fruits. Legume (Dolichos, Pisum of Fabaceae), Capsule (Septicidal in Aristolochia, Loculicidal in Gossypium and Abelmoschus and Septifragal in Datura) are Dry dehiscent fruits. Caryopsis (Oryza, Triticum of Poaceae), Cypsela (Tridax, Tagetus of Asteraceae) and Nut (Anacardium occidentalis) are Dry indehiscent fruits. Lomentum (Acacia, Mimosa) and Schizocarp (Abutilon, Sida or Malvaceae) are Schizocarpic fruits. Model Questions 1. Fibrous thickenings of Endothecium of microsporangium are chemically made of 1) Pectin 2) Lignin 3) Suberin 4) Cellulose 2. All the nuclei of embryosac do not have same genetic constitution in i) Polygonum ii) Allium iii) Peparomia iv) Fritillaria 1) i, ii, iii 2) i, iii, iv 3) ii, iii, iv 4) i, ii, iv 3. Study the following and identify the correct match A. Ovules with I) Brassicaceae 360° curvature B. Ovules with 90° II) Asteraceae curvature C. Ovules with 120° III) Polygonaceae curvature D. Ovules with 180° IV) Plumbaginaceae curvature V) Primulaceae A B C D 1) IV V III II 2) IV III II I 3) III V I II 4) IV V I II Key: 1) 4; 2) 3; 3) 4 Plant Taxonomy SYNOPSIS In this usually 3-5 questions are asked. Some questions are direct. Some are application type. Matching, Assertion & Reason type, Item group and Sequence type questions are asked. Introduction Identification, classification and nomenclature are the 3 aspects of taxonomy. Identification is done with the help of Herbaria, Floras and Computer punch card keys. Plants are named according to the rules of ICBN and Binomial nomenclatural system is followed. Tautonyms are discarded in Plant nomenclature. Artificial systems of classifications are based on one or few easily comparable characters. e.g. Theopharastus classification and Sexual system of classification (24 classes and 87 orders) of Linnaeus. Natural system are based on all morphological characters e.g. de Jussieu, de Candolle and Bentham and Hooker classifications. Phylogenetic systems are based on genetic and evolutionary evidences. e.g. Eichler, Engler and Prantl, Hutchinson, Rendle, Bessey classifications. Multidisciplinary systems are phylogenetic which not only use morphological data but also evidences from other branches. e.g. Takhtajan, Thorne, Goldberg, Cronquist and Shipnov classifications. Kingdom is the largest and Species is the basic unit of classification. Bentham and Hookers system is a natural system of classification of flowering plnts, written in latin as Genera Plantarum with 3 volumes, 3 classes, 3 subclasses, 21 series, 25 orders, 202 families and 97,205 species. Malvaceae Its plants are Abutilon indicum (Tutturu benda - Medicinal), Abelmoschus esculentum (Benda- vegetable), Althaea rosea (Hollyhock - ornamental), Gossypium herbaceum(Cotton - Textile industry), Hibiscus rosa-sinensis (Chinarose - ornamental), H. cannabinus (Madras hemp - leafy vegetable, fibre yielding), Hibiscus micranthus(Nityamalle-ornamental), Malvaviscus arboreus (Mirapamand-ara - ornamental), Thespesia populnea (Gangaravi - ornamental) and Sida cordifolia (medicinal plant). Fabaceae The plants are: 1. Arachis hypogea (Groundnut - Oilseed and fodder crop), 2. Abrus precatorius (Crab's eye - Seeds are used as weights by Goldsmiths), 3. Butea monosperma (Flame of the Forest), 4. Cajanus cajan (Pigeon pea or Red gram - Pulses), 5. Cicer arietinum (Bengal gram or Chick pea - Pulses), 6. Crotalaria juncea (Sun hemp - Fodder and Fibre crop), 7. Dolichos lablab (Bean - fruit vegetable), 8. Dalbergia latifolia (Rose wood - Wood for furniture), 9. Derris indica (Kanuga - seed oil as medicine), 10. Glycine max (Soy bean - Seed oil, fruit vegetable), 11. Indigofera tinctoria (Blue dye plant - fabric whitener), 12. Lathyrus sativus (Wild pea), 13. Phaseolus mungo (Black gram - Pulses), 14. Phaseolus aureus (Green gram - Pulses), 15. Pisum sativum (Peas - Pulses), 16. Pterocarpus santalinus (Red sanders - wood used in making musical instruments), 17. Sesbania sesban (Avisa - Green manure), 18. Tephrosia purpurea (Vempali - Green manure), 19. Trigonella foenum-graecum (Fenugreek, Menthulu - medicinal, Spice and leafy vegetable) and 20. Ulex (Xerophyte). Solanaceae It's plants are: 1. Atropa belladonna (Belladona - Belladona has alkaloid Atropine and used in Belladona plasters), 2. Capsicum fruitescens (Chillies - Vegetable, condiment, spice, Pickle), 3. Cestrum nocturnum (Night queen Ornamental), 4. Cestrum diurnum (Day king - Ornamental), 5. Datura metal (Thorn apple Leaves in Asthama control), 6. Hyoscyamus niger (Kurashani-Vamum - Medicinal), 7. Lycopersicon esculentum (Tomato - Vegetable), 8. Nicotiana tabacum (Tobacco - Nicotine), 9. Petunia alba (ornamental), 10. Physalis minima (Sun berry - fruits are edible), 11. Physalis peruviana (Gooseberry), 12. Solanum melongena (Brinjal), 13. Solanum tuberosum (Potato), 14. Solanum nigrum (Kamanchi - Medicinal), 15. Solanum surattense (Vakudu - Leaves to control asthama), 16. Solanum tuberosum (Potato - Vegetable) and 17. Withania somnifera (Aswagandha - Medicinal). Liliaceae The plants are: 1. Allium cepa (Onion - Vegetable with bactericidal properties), 2. Allium sativum (Garlic - Medicina, Spices), 3. Aloe barbadensis (Kalabanda - Piles treatment), 4. Asparagus racemosus (Sathamuli - Vegetable), 5. Colchicum autumnale (Meadow Saffron - Colchicine a mutagen is obtained) 6. Dracaena angustifolia (Red Dragon - Fibre yielding), 7. Gloriosa superba (Glory lily - Ornamental, Medicinal), 8. Lilium candidum (Lily - ornamental), 9. Ruscus aculeate (Butcher's broom-Medicinal), 10. Scilla hyacinthiana (Squill-Medicinal), 11. Smilax zeylanica (Sarasaparilla - Roots as medicine) and 12.Yucca gloriosa (Spanish dagger- Leaves yield fibre). Model Questions 1. Bentham and Hooker classified series directly into natural orders in i) Gamopetalae ii) Monochlamydae iii) Manocotyledonae 1) i and ii are correct 2) i and iii are correct 3) iii alone is correct 4) ii and iii are correct 2. Assertion:Nicotiana belongs to Solanaceae. Reason: It has straight embryo. 1) A and R are correct, R explains A 2) A and R are correct,R does not explain A 3) A is correct, R is wrong 4) A is wrong, R is correct Key: 1) 4; 2) 2 Cell Biology SYNOPSIS In this 2-3 questions are asked, usually one from cell organelles, one from chromosomes and nucleic acids and one from cell division. Usually a problem is asked from DNA or Chromosomes. Cell wall was discovered and named by Robert Hooke. It has Middle lamellum with Ca, Mg pectate formed from Cell plate. Its Primary wall is thin, elastic and has a cellulose frame work embedded in Pectin, hemicellulose matrix. The thin areas in the wall are called as Primary pit fields which are traversed by Plasmodesmata involved in intercellular transport. It has thick, rigid and impermeable Secondary wall which has cellulose frame work embedded in Lignin, Suberin and Cutin matrix. It has depressions known as Pits. Plasma membrane is lipoproteinaceous, elastic with 7.5nm thick. Danielli and Davsons trilamellar model, Unit membrane concept of Robertson and Fluid Mosaic model of Singer and Nicolson (most acceptable) explain the structure of Plasma membrane. Cytoplasm has 85 to 90% water, 7-10% proteins, cytoskeleton. It shows circulation in staminal hairs of Rheo discolor and Rotation in epidermal cells of hydrophytes like Vallisneria and Hydrilla. It has Cell organelles like Plastids, Mitochondria, E.R., Glogi complex, Ribosomes, Lysosomes, Glyocysomes, Peroxisomes, Nucleus and Ergastic substances. Vacuoles were discovered by Sphalanjani and have tonoplast, and tonoplasm. These are commonly called as Repositories of cell. Chromosomes Chromosomes are up to 30µ in length as in Trillium and attain V, L, J and I shapes in anaphase. The diploid chromosome number of Haplopappus gracilis is 4, Pisum sativum 14, Allium cepa 16, Zea mays 20, Oryza sativa 24, Nicotiana tabacum 48, Gossypium 52, Saccharum 80 and Ophioglossum 1260. A metaphasic chromosome has two chromonemata, a centromere, telomeres, secondary contstriction etc. Electron microscopic studies of Kornberg and Thomas revealed that chromatin has bead like structures called as Nucleosomes (Oudet). Nucleic acids The DNA structure given by Watson and Crick is based on the facts established by Chargaff, Franklin, Wilkins and Pauling. DNA molecule resembles a clockwisely twisted ladder and has two antiparallel strands with 5'3' polarity. The backbone of each strand has alternately arranged Deoxyribose and Phosphate with diester bonds between them. Nitrogen base is attached to the sugar towards the interior of DNA molecule. Purin-

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5

JUNIOR INTER

CELL DIVISION

INTERNAL ORGANISATIONS

Dicot leaf has epidermis with..

es and Pyrimidines exist in 1:1 ratio. A of one strand pairs with T of opposite one and 2 hydrogen bonds are formed between them. Similarly 3 hydrogen bonds are formed between G and C. Length of DNA is variable. Diameter is 20Ao, length of each helix is 34Ao, distance between adjacent nucleotides is 3.4Ao and angle is 36o. Each helix has 10 pairs of nucleotides. These features are for B-DNA. Z-DNA was discovered by Rodley and coiled in clockwise and anticlockwise manner. Replication of DNA is by semiconservative manner in S stage of cell cycle. RNA has 3 types: mRNA, rRNA and tRNA. Cell Division Cell cycle has Interphase and M phase stages. Inter phase has G1 stage with RNA and protein synthesis and enlargement of cell, S stage with DNA synthesis and G2 stage with RNA, protein and energy reserves synthesis and increase in cell organelle number. Mitosis was discovered and named by W. Flemming. Kayokinesis has Prophase with chromosome condensation, disappearance of nucleolus and nuclear membrane, Metaphase with organization of spindle and equatorial plate, Anaphse with division of chromosome and movement of daughter chromosomes towards poles and Telophase with the formation of daughter nuclei at poles. In cytokinesis a fluid plate called Cell Plate is formed by Golgi in the Phragmoplast which develops into Middle lamellum. Model Questions 1. Lysosomes arise from i) Cisternae of E.R., ii) Tubules of E.R. iii) Cisternae of golgi, iv) Tubules of golgi 1) i and iii 2) ii and iii 3) iii and iv 4) i, ii, iii 2. Double membrane bound cell organelles are I. Nucleus II. Mitochondria III. Plastids IV. E.R. 1) I, II, III, IV 2) I and II 3) I, II and III 4) II, III and IV 3. Match the following and identify the correct match A. DNA I) Pseudohelices B. m RNA II) Twisted ladder C. t RNA III) Straight, unfolded, stranded double D. r RNA unfolded IV) Straight, stranded single V) Clover leaf A B C D 1) III II IV I 2) II IV V I 3) IV II III I 4) V IV II I Key:1) 2; 2) 3; 3) 2 Internal Organisation of Plants SYNOPSIS This is the topic that has to be concentrated. Usully 3-4 questions are asked. These are sequence type, multiple answers and matching. A few questions are direct and easy. Tissues Plants have 2 types of tissues i.e. Meristems and Permanent tissues Nageli coined the term meristem. Meristems are primary, secondary, apical, intercalary and lateral meristems. Permanent tissues are differentiated tissues and of 3 types called Simple, Complex and Special tissues. Parenchyma is simple living tissue. It performs photosynthesis (Chlorenchyma as palisade and spongy), Storage (food materials or excretory materials or water as in Aloe, Bryophyllum, Opuntia), Aeration and buoyancy (hydrophytes), protection (epidermis) and meristematic activity fuctions. Collenchyma is simple living mechanical tissue. Majumdar identified it as 1. Angular collenchyma 2. Lacunar collenchyma and 3. Lamellar collenchyma. Sclerenchyma is simple dead mechanical tissue whose cells have pitted lignified secondary walls, narrow lumen and without intercellular spaces. These cells are fibres and sclereids. Fibres are elongated cells with tapering ends. Soft fibres such as Hemp (Cannabis), Sunhemp (Crotalaria), Jute (Corchorus), Flax (Linum) and Ramie (Boehmeria) have less or no lignin and have more commercial value. Hard fibres have more lignin and obtained from the leaves of Musa, Yucca and Agave. Sclerieds are parenchyma like Brachy sclereids (Cocos, Pyrus), Cylindrical Macrosclereids (Fabaceae seed coats), bone like Osteosclereids (Cotyledons of dicots like Mouriria, leaves of Hakea), star like Astrosclereids (Nymphaea), thread like Filiform sclereids (leaves of Olea) and hair like branched Trichosclereids(Olea leaves and Monstera roots). Complex tissues are xylem and phloem and present in tracheophytes. The terms xylem and phloem are given by Nageli and formed from procambium in primary plant body and vascular cambium in secondary plant body. Xylem is mineral water conducting dead tissue also known as Hydrome and consists of tracheary elements tracheids and vessels, xylem parenchyma and xylem fibres. Phloem is organic food materials conducting living complex tissue which has conducting sieve elements, Companian cells, phloem parenchyma and phloem fibres. Secretary tissues are also called as Special tissues. Its cells have protein rich protoplasm and may be polyploidy. It is of various types. They are Digestive glands, Neectaries, Osmophores, Secretary spaces, Hydathodes and Laticifers. Internal structure of Root It has epidermis with root hairs called as Rhizodermis or Epiblema or Piliferous layer, Cortex with 2-3 layered (Dicot) or 1-2 layered (Monocot) Exodermis with suberised walls, many layered parenchymatous general cortex with intercellular spaces, single layered Endodermis with casparian strips made of Lignin and Suberin and some cells lacking it (Passage cells present opposite Protoxylem) and Stele having single layered pericycle that gives rise lateral roots, Radial vascular bundles with Exarch condition. In Monocots, the stele is polyarch and prominent medulla is present. There is no secondary growth. Internal Organisation of Stem The Dicot stem has Epidermis, Cortex and Stele. Epidermis is single layered with stomata, trichomes and surrounded by cuticle. Cortex is demarcated into continuous (Helianthus) or discontinuous (Cucurbita) collenchymatous Hypodermis, Multilayered general cortex with peripheral chlorenchymatous region and inner achlorophyllous region and single layered endodermis that stores starch (Starch sheath) and has casparian strips. Stele has multilayered completely (Cucurbita) or incompletely (Helianthus) sclerenchymatous pericycle, Collateral or bicollateral (Solanaceae), conjoint, open endarch vascular bundles arranged in the form a ring (Eustele) and surround the central prominent Parenchymatous Medulla (Siphono stele) and separated by medullary rays that help in radial conduction. Monocot stem has single layered epidermis without hairs but with stomata and cuticle, Sclerenchymatous continuous hypodermis and ground parenchyma with scattered, many conjoint, collateral, closed, endarch vascular bundles of different sizes (Atactostele). Each vascular bundle is surrounded by sclerenchymatous bundle sheath, has four vessels with 2 belong to Metaxylem and 2 belong to Protoxylem with lacuna arranged in the form of V or Y. Medulla, Medullary rays, Pericycle, Endodermis and general cortex are not organized. Phloem parenchyma is absent. Internal organization of Leaf Dicot leaf has epidermis with barrel shaped cells in the adaxial and abaxial sides surrounded by cuticle, with stomata only on the lower epidermis or more in the abaxial epidermis. Mesophyll is demarcated into adaxial Palisade with larger cylindrical cells having more chloroplasts, abaxial spongy tissue with less chloroplasts primarily behaves has ventilating tissue. The vascular bundles have parenchymatous bundle sheath with conjoint, collateral closed endarch condition and bundle sheath extensions. Monocot leaf has single layered epidermis without hairs but almost equal number of stomata in the upper and lower epidermis, homogenous mesophyll, and vascular bundles with 1 or 2 layered bundle sheath having scerenchymatous extensions and conjoint, collateral and closed nature. In grasses, some of the cells of upper epidermis are larger, thin walled, arranged in the form of fan and help in rolling and unrolling of lamina. These cells are called as Bulliform cells or Motor cells. In some plants the bundle sheath has chloroplasts. Secondary Growth of Dicot stem Increase in thickness of the axis due to the activity of lateral meristems is called as Secondary growth. Medullary ray cells get dedifferentiated into interfascicular cambium and its eventual fusion with the fascicular cambia of vascular bundles to form vascular cambium is the first step in stelar secondary growth. This one divides periclinally and forms more secondary xylem towards the centre and relatively less secondary phloem (Bast) towards the periphery. It has Fusiform initials that give rise bulk of the secondary vascular tissues and ray initials form ray parenchyma of secondary xylem(wood ray) & secondary phloem (Bast ray). Annual rings are formed by secondary xylem of temperate and sub-tropical plants. Dark colored,functionless secondary xylem is heart wood and light colored secondary xylem is sap wood. Extra stelar secondary growth is started with the formation of cork cambium from the cells of cortex. It cuts more dead tissue known as cork towards the periphery and less living green tissue with intercellular spaces towards the centre known as secondary cortex. These three together called as periderm. All tissues of plant present outside vascular cambium together called as Bark. Model questions 1. Monocot stem differs with the Dicot stem in the following internal features I. Epidermis without stomata II. Absence of Trichomes III. Sclerenchymatous hypodermis 1) I, II 2) II, III 3) I, III 4) I, II, III 2. In a 20 years old dicot plant, if an early wood of an annual ring has no contact with late wood towards interior, the early wood belongs to 1) Last annual ring 2) 1st annual ring 3) annual ring of any yea 4) recent annual ring of heart wood Key: 1) 2; 2) 2

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6

JUNIOR INTER

HYDROPHYTES

PLANT GENETICS

Hydrophytes... Plants that grow in...

Plant Ecology SYNOPSIS Only one question or seldom two questions are asked. This topic is morphology based. It is very easy topic which requires a superficial revision of 10 hours before the exam as it has several examples. Model Questions 1. Arrange the following plants in a sequence that depicts gradual increase in drought tolerance. I. Tribulus II. Casuarina III.Cyperus IV. Asparagus 1) III, I, IV, II 2) III, I, II, IV 3) I, III, II, IV 4) I, III, IV, II 2. [A]: All succulent stems of xerophytes are photosynthetic [R]: All phylloclades are succulent 1) Both A and R are true and R is the correct explanation of A 2) Both A and R are true but R is not the correct explanation of A 3) A is true but R is false 4) A is false but R is true Key: 1) 1; 2) 3 Plant Genetics SYNOPSIS This topic has been included only from last year. It requires sound knowledge of cell division, chromosomes and nucleic acids. Probability based questions can be asked. Genetics is the study of heredity and variations. The term was given by Bateson and Mendal laid foundations for genetics. Cross between parents which differ in a pair of characters is called as Monohybrid cross. In the monohybrid cross he crossed homozygous tall (TT) plants with dwarf plants (tt) and obtained only tall plants in F1 generation with Tt as genotype. When he selfed these hybrids, he obtained the tall to dwarf plants in the ratio of 3:1 and the genotypes TT, Tt and tt in the ratio of 1:2:1. From this he concluded that tall as dominant and dwarf as recessive. He observed that though the alleles T and t are present in the hybrid they do not blend and separated during gametogenesis due to meiotic segregation and the gametes of F1 have either T or t allele but not both in the same gamete. Based on this he proposed the Law of Segregation. Cross between two parents differing in two characters is called as dihybrid cross. Mendel homozygous Yellow and Round seeded plants (YYRR) with green wrinkled seeded (yyrr) and obtained heterozygous Yellow Round seeds (YyRr) in F1 generation. When he selfed these He obtained the Yellow Round, Yellow wrinkled, Green Round and Green wrinkled seeds in the phenotypic ratio of 9:3:3:1. He obtained the genotypes YYRR, YyRR, YYRr, YyRr, YYrr, Yyrr, yyRR, yyRr and yyrr in the ratio of 1:2:2:4:1:2:1:2:1. He obtained two new phenotypes as Yellow wrinkled and Green round seeds (Mendelian recombinants). He proposed the Law of Indepen-dent Assortment. Cross between F1 hybrid and one of the parents is called as Back cross. If the parent is homozygous dominant one, only one phenotypic plants are obtained in both Monohybrid and Dihybrid back cross. If the F1 hybrid is crossed with the recessive parent, it is called as test cross. In Monohybrid test cross the phenotypic and genotypic ratio is 1:1 and in dihybrid test cross the phenotypic and genotypic ratio is 1:1:1:1. Probability cocept is applied in Genetics to analyse the results. Bateson and Punnet discovered that in some cases pair of contrasting characters didn't separate and inherited together for several generations linkage was experim-entally demonstrated with proof by Morgan in Drosophila and Maize for which he prepa-red Chromosomal maps and was given Nobel Prize. Bateson and Punnet Crossed the Lathyrus odoratus plants showing difference in flower colour and Pollen grain shape. They crossed the dominant Blue flowers, long pollnegrain female parent (RR R0R0) with Red flowers, spherical pollen grains (rr r0r0) and obtained Blue long plants with heterozygous condition (Rr R0r0). When this hybrid was test crossed they obtained Blue Long, Blue spherical, Red long and Red spherical plants in the ratio of 7:1:1:7 ratio which is quite different from Mendel's dihybrid test cross ratio. This clearly indicated linkege. Sudden inheritable change in an organism is called as Mutation or discontinuous variation. It was discovered by Hugo de Vries in Oenothera lamarkinana and the results were published as 'Die Mutation Theorie'. The organism subjected to mutations is mutant and the agent that causes it is called as mutagen. Mutations are spontaneous, induced, chromosomal and gene mutations. Model Qeustions 1. Study the following table and choose the correct combination Phenotype of F2 individual of dihybrid cross of Pisum sativum I) Green wrinkled seeds II) Green round seeds III) Yellow round seeds IV) Yellow wrinkled seeds Possible genotype yy Rr yy RR Yy RR Yy rr Probability of genotype ¼X½ ¼X¼ ½X½ ½X¼ Plant Kingdom SYNOPSIS About 4-5 questions are asked in various ways. It is one of the diciding chapters. It has to read with concentration. Scoring marks in this is relatively easy. Spirogyra It is commonly called as Pond Scum, Pond silk and Water silk. Thallus is unbranched filamentous, multicellular & uniseriate. It has cylindrical cells with pectocellulosic wall, haploid nucleus suspended in the central large vacuole and parietal 1-16 ribbon shaped chloroplasts having starch storing pyrenoids. It vegetatively reproduces by Fragmentation and asexually by Akinete formation in S. farlowii and Aplanospore formation in S. aplanosporum. It sexually reproduces by Conjugation. It may be Scalariform conjugation (Physiological anisogamous or Isogamous), Indirect lateral conjugation (Physiological anisogamous as in S.affinis) or Direct lateral conjugation (Anisogamous as in S.jogensis, S. mirabilis). Zygospore has triple layered wall, diploid nucleus, proplastids and oil droplets. During its germination it shows meiosis and forms germ tube which later develops into filament. Its life cycle is haplontic. Rhizopus Mycelium is branched filamentous, aseptate, coenocytic and has Rhizoids, Stolons in vegetative stage. Sporangiophores are formed during asexual reproduction. Cell wall is chitinous, reserve food materials are glycogen, oil and has several vacuoles. Asexual reproduction takes place by Sporangiospore formation and Chlamydospore formation. Sporangiophores are formed opposite to rhizoids on the upper surface of stolons. It has terminal sporangium. Sporangium has peripheral nucleated (Sporoplasm) and central vacuolated region (Columelloplasm). These are separated by a layer of dome shaped vacuoles which eventually fuse, form cleft into which a wall is secreted. Sporiferous zone is cleaved into small 2-10 or uninucleated bits which eventually secrete a thin wall to transform into Sporangiospores. Columella enlarges and helps in the dehiscence of sporangial wall. Chlamydospores are thick walled spores formed singly in older hyphae during unfavourable conditions. It sexually reproduces by Gametangial coupulation. Heterothallic species (R. stolonifer) are more common than Homothallic species (R.sexualis).

The term Ecology was given by Reiter. Warming defined it as study of organisms in relation to environment, Odum defined as study of structure and function of nature. A group of individuals of a species living in an area is called as Population, a group of different species in an area is Community. Ecosystem is structural and functional unit of nature which shows interaction between living and non-living organisms and the term was given by Tansley. Biologically inhabited part of the earth is called as Biosphere or Ecosphere. Hydrophytes Plants that grow in water or very wet places Pistia, Eichhornia, Wolffia and Salvinia are free floating, Nymphaea, Nelumbo, Victoria are rooted hydrophytes with floating leaves, Hydrilla, Ceratophyllum and Utricularia are submerged sustpended hydrophytes, Vallisneria and Potamogeton are rooted submerged hydrophytes and Sagittaria, Limnophila, Ranunculus and some others like Typha and Cyperus are Ampnibious hydrophytes. Cuticle is thin, stomata are either present (Epistomatous in Nymphaea) or absent or functionless (Potamogeton). Epidermis is thin walled with chloroplasts, Cortex and mesophyll is aerenchymatous, More spongy tissue, poorely developed mechanical and vascular tissues (Xylem is less developed than Phloem). Xerophytes These plants grow in water deficient conditions. Tribulus is ephemeral, Opuntia is stem succulent, Bryophyllum, Aloe and Agave are leaf succulents, Asparagus is root succulent. Casuarina, Nerium, Zizyphus and Calotropis are true xerophytes. Thick cuticle, thick walled epidermis, hypostomatous condition, sunken stomata, stomata surrounded by hairs (Nerium), multiple epidermis, sclerenchymatous hypodermis, more palisade than spongy, Mesophyll or cortical cells storing water, Epidermal cells with silica crystals, well developed vascular tissues are the anatomical features.

1) I and II 2) III and IV 3) I and IV 4) II and IV 2. If Oryza sativa has 4 copies of 12th chromosome, the ploidy of the plant is best described as 1) Tetraploid 2) Tetrasomic 3) Double Trisomic 4) Double trisomic Key:1) 4; 2) 2

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7

JUNIOR INTER

FUNARIA

MICRO BIOLOGY

Indian wild species of Cycas are..

Trisporic acids regulate it. Zygophores of opposite strains give out copulating branches (Progametangia) at the point of contact which become two celled (Suspensor & Gametangium),upon septum formation. Gametangia fuse, Nuclei of opposite strains pair, fuse and form diploid nuclei and the structure is called as Zygospore. Unpaired nuclei gradually degenerate. Diploid nuclei of zygospore undergo meiosis to form haploid nuclei, exine is ruptured and Promycelium is fomed. Tip of promycelium forms germ sporangium in which germspores are formed and eventully dispersed. Life cycle is haplontic. Funaria Funaria belongs to Division Bryophyta, Class Bryopsida, Order Funariales and family Funariaceae. It has 117 species and known as Cord moss, Fire moss and Mixohydric moss The dominant stage in the life cycle Gametophyte has alga like Protonemal stage and adult Gametophore with multicellular rhizoids having oblique cross walls, cauloid and phylloids. Stem has dead hydroids that conduct mineral water. It vegetatively reproduces by Secondary protonema, Gemmae and Tubers. Gametophore is monoecious, autoicous, protandrous and sexually reproduces by zooidogamous oogamy. Male branch has multicellular stalked antheridia that produces biflagellated chemotactic sickle shaped male gametes, capitate paraphyses and perichaetial leaves. Female branch has stalked archegonia with twisted neck, 6to many NCC, VCC that form sugary mucilage, an egg cell and one (Neck) and Two layered (Venter) jacket, paraphyses and perichaetial leaves. Sporophyte is semi-parasite on the female branch of gametophore, has Foot, Seta and spore producing Capsule with photosynthetic Apophysis, fertile Theca and cap like Operculum with Peristome, Annulus and Rim. Spore sac of theca produces haploid meiospores due to meiotic divisions in spore mother cells that have chloroplasts and oil droplets. Spores germinate and form protonema and buds of protonema form gametophores. Life cycle is haplodiplontic and shows heteromorphic alternation of generations. Pteris It has 280 species and belongs to class Leptosporangiopsida, order Filicales and family Polypodiaceae. Dominant stage is sporophyte which has perennial Rhizome, Imparipinnate leaves with open dichotomous venation in leaflets which show circinate vernation and brown hair ramenta and adventitious roots. Rhizome has epidermis with thick cuticle, sclerenchymatous hypodermis, dictyosetele with mesarch xylem. Sporophyll has 2 sori per leaflet and sorus is mixed, linear and coenosorus type with false indusium, placenta & paraphyses. Sporangium has pedicel, capsule with 1-layered jacket having hygroscopic annulus and stomium with lip cells, 1-2 layered tapetum and 48 spores. Spores are dispersed by Sting/Catapult movement of Annulus. Gametophyte is monoecious, protandrous, dorsiventral, anterior-posterior, cordate, parenchymatous with discoid chloroplasts, has unicellular rhizoids, antheridia at the posterior and archegonia nearer to the notch. Antheridium is globose, has 3-celled jacket & 32 multiciliated, highly coiled male gametes. Archegonium has 16 jacket cells in 4 rows, a binucleate NCC, a VCC and egg. Its mucilage rich in Malic acid attracts the male gametes (Chemotaxy). Fertilization is zooidogamous oogamy. Embryo forms adult sporophyte that respectively forms primary root, leaf, Rhizome and adventitious roots. Life cycle is Diplohaplontic and Alternation of generations is heteromorphic. Cycas Genus Cycas has 20 species . Indian wild species of Cycas are C. circinalis (Crozier Cycas), C. beddomei (Madras Cycas), C. pectinata (Nepal Cycas) and C. rumphii (Rumphious Cycas). Its plant has caudex stem with persistent leaf bases, paripinnate foliage leaves with circinate vernation, ramenta and some spinous leaflets, scale leaves and normal and coralloid (with BGA Nostoc or Anabaena) adventitious roots. Coralloid roots have periderm with lenticels (for gaseous exchange), cortex with drusses and BGA, 2-3 layered pericycle and Triarch xylem. Pinnule is hypostomatous with sclerenchymatous hypodermis, differentiated mesophyll, Primary and secondary transfusion tissue for lateral conduction and diploxylic pseudomesarch open vascular bundle. Cuticle is thick It is dioecious. Male cone has few sterile and many fertile Triangular, spirally arranged microsporophylls with apical sterile apophysis and many microsori (2-6 sporangia) surrounded by indusial 1 or 2 celled hairs on abaxial side. Microsporangium has 5-6 layered wall with exothecium having thickened radial and tangential walls and haploid pollen grains released at 3-celled stage. Pollination is direct and anemophilous. Adult male gametophyte has prothaliial, vegetative, stalk cells and 2 multiciliated top shaped largest male gametes. Pollen tube is haustorial in nature. Megasporophyll has 2-12 largest ovules in two rows in the notches of margins of the middle region. Ovules are vascularised, orthotropous, unitegmic (Tripartite), crassinucellate, with archegonial chamber and pollen chamber formed by the degeneration of nucellus and forms multicellular female gametophyte (Endosperm) with 2-8 archegonia after megasporogenesis. Archegonia have 2 neck cells,VC nucleus and egg but lack NCC and venter. Fertilization is siphonogamous and zooidogamous Embryo respectively has haustorium, coiled suspensor, coleorhiza, radicle, hypocotyle, 2 cotyledons and plumule. Seeds are haploid endospermic, perispermic, polyembryonic and ornithochorous and show hypogeal germination. Model Questions 1. Choose the incorrect statement 1) All leaflets of Pteris are similar in shape 2) All leaflets of Pteris leaf are arranged in pairs 3) Leaflets of Pteris are dissimilar in size 4) Basal most leaflets of Pteris leaf are the smallest 2. Arrange the following structures of Cycas leaf let from adaxial side to abaxial side. I. Phloem II. Metaxylem of Centripetal xylem III. Metaxylem of Centrifugal xylem IV. Protoxylem of Centrifugal xylem 1) I, III, IV, II 2) II, III, IV, I 3) II, IV, III, I 4) IV, II, III, I Key: 1) 2; 2) 3 Microbiology - Bacteria SYNOPSIS Weitage of this topic is 2 marks. One from bacteria and another one from viruses. It has several examples which have to memorized with caution and time and again. Matching, A/R and item group questions are asked. Roger Stanier opined for considering culture methods along with size of the organisms for defining bacteria. Bacteria were discovered by Leeuwenhoek, named by Ehrenberg and extensively studied by Louis Pasteur and Robert Koch. Structurally they have peptidoglycan cell wall, Glycocalyx with polysaccharides, variously distributed flagella made of flagellin, adhering appendages pili made of pilin, cell membrane with respiratory functions, chlorosomes vesicles or photosynthetic cell membrane invaginations, some with gas vacuoles (Halobacterium), nucleoid having only one circular chromosome made of DNA, some with extrachromosomal DNA rings (plasmids) and reserve foods in the form of Glycogen or PBH. Nutritionally bacteria are recognized as Photoautotrophs (Chlorobium, Chromatium), Photoheterotrophs (Rhodo bacteria), Chemoautotrophs (Hydrogen, Nitrifying, Sulphur and Iron bacteria) and Chemoheterotrophs (Saprophytes, Parasites and Symbionts). They asexually reproduce by Binary Fission in favourable conditions. Though true sexual reproduction is absent they show genetic recombination by ways of Transformation (Griffith in Streptococcus pneumoniae), Conjugation (Lederberg and Tatum in E.coli) and Transduction (Zinder and Lederberg in Salmonella typhimurium). For economic importance see quick review (page no. 12.) Viruses Viruses are infectious, ultramicroscopic, acellular, nucleoprotein particles Vaccinia virus is the largest and smallest is f2 bacteriophage. Viruses may be rod like (TMV), rectangular (Vaccinia virus),-Polyhedral(Adenovirus), Spheroidal (Polio virus), Tadpole shaped (Bacteriophage) and Bullet shaped (Rhabdo virus). Chemically all viruses have protein coat Capsid made of capsomers and one of the nucleic acids which may be ssRNA (TMV, Polio virus, Influenza virus), dsRNA (Reo virus, Wound Tumour virus, Rice dwarf virus, Maize rough dwarf virus, Blue tongue virus, Bacteriophage 6), ssDNA (Bacteriophages M13 & x174) & dsDNA (Most animal viruses, Bacteriophages, Cyanophages, CMV, DMV). Most of the animal viruses have an additional carbohydro-lipoproteinaceous covering Peplos or Envelope made of units Peplomers (HIV, Influenza virus). Viral symmetry is based on arrangement of capsomers and can be Helical (TMV), Cubical (Adeno virus) and Binal (Bacteriophage). Infectious nucleic acid particles are called as Viroids (Potato spindle tuber virus, Citrus exocortosis virus). Infectious protein particles are called as Prions. They cause diseases such as Scrapie in Sheep and Mad cow disease. TMV is 300 X 18-19 nm, its central hole is 4nm, 39 X 106 daltons mol.wt., capsid with helically arranged capsomers, each capsomer with 158 amino acids and ssRNA having 6500 nucleotides. Bacteriophage was discovered by Twort and named by Herelle. T4 Phage has a head with dsDNA (1000 times longer than Phage) and

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8

SENIOR INTER

TRANSPIRATION

NUTRITION

Potassium is required for..

semipermeable capsid, a tail with core surrounded by sheath having 144 helically arranged capsomers and sealed by hexagonal end plate with 6 spikes and 6 jointed tail fibres, a collar between Head and Tail. Bacteriophages replicate by Lytic and Lysogenic cycle. Lytic cycle is shown by T even phages and has 1. Adsorption stage (Virus attaches to bacterium with tail fibres), 2. Penetration stage (Viral DNA is sent into the bacterium after the action of lysozyme and contraction of tail sheath), 3.Latent stage (Viral DNA takes over the functions of bacterium and destroys the bacterial DNA {Eclipse} and forms viral particles by synthesizing capsid proteins and viral DNA {Maturation stage} and 4.Lytic stage in which the bacterial cell wall is broken and viruses are released. Lysogenic cycle is shown by bacteriophages in which the viral DNA is integrated into bacterial DNA and carried to successive generations of bacteria. Viral plant diseases are Chlorosis, Mosaic, Vein cle-aring, Vein banding, Ring spots, Dwarfing, Malfor-mation and Floral break. Viral diseases are transmitted through vegetative parts, Mechanical methods, Seeds, Pollen grains, Insects, Nematodes like Xephenema and Longidorus, Fungi and parasitic angiosperms like Cuscuta. Exclusion of source of Infection, Isolation of source of infection, Eradiacation of Vectors, Chemotherapy,and Breeding disease resistant varieties are the control measures to prevent viral diseases. Model Questions 1. [A] : All spirochaetes are spirillae. [R] : All spirillae are spirochaetes. 1) A and R are correct and R is the correct explanation of A 2) A and R are correct but R is not the correct explanation of A 3) A is true but R is false 4) A is false but R is true 2. Study the following and identify the correct match Disease Transmitting agent A. Bean mosaic I) Nematode disease B. Papaya mosaic II) Seeds disease C. Tobacco necrosis III) Pollen grains D. Cherry ring spot IV) Fungus V) Insects A B C D 1) V II I III 2) II V IV I 3) II IV V I 4) II V IV III Key: 1) 3; 2) 4 Plant Physiology Absorption of Water and Ascent of Sap SYNOPSIS This is the very very important Chapter from which 7 to 11 questions are asked. The questions are of all the types. The biochemical pathways have to drawn and memorized again and again. Problem based questios are asked from metabolism. cell is zero. Hence the = . Absorbed water mostly moves from root hair to endodermis through cell walls. It is called as Apoplastic pathway. From endodermis it move into xylem via pericycle through protoplasm and cell membrane. It is called as Symplastic pathway. Out of all theories, Dixon's Cohesion and Tension theory best explains Ascent of sap. It is based on 3 principles i.e. Transpiration Pull, Cohesive force of Water (-30MPa) and Adhesive force of water. The main force is Transpiration pull or tension developed in the xylem due to transpiration. The 2 drawbacks of the theory are 1. Fail to explain ascent of sap when there is embolism due to cavitation and 2. Stating tracheids as more efficient than vessels. Transpiration Levitt and Bowlings K+ pump hypothesis best explains stomatal movement. In light, Malic acid formation from starch, expulsion of H+ of Malic acid into subsidiary cells by using ATP, influx of K+ and Cl- in to guard cells decreases of guard cells and stomata are opened - Active process. In absence of light K+, Cl-, malate- move passively into subsidiary cells and H+ into guard cells. Malic acid is oxidized in respiration. It results in increased , water moves into subsidiary cells and stomata are closed- Passive process. In the presence of light, increase in temperature, availability of more water, gentle wind velocity and less atmospheric humidity, transpiration rates increase. With increase in leaf area,stomatal frequency, root-shoot ratio, transpiration rates increase. Transpiration has several advantages and few disadvantages to plant. Hence it is described as necessary evil by Curtis and as unavoidal evil by Barnes. PMA, ABA, Asprin decrease transpiration by acting as metabolic inhibitors. Waxes, Silicon oils and Plastic emulsions are film forming antitranspirants. High CO2 concentration also acts as anti-transpirant. Nutrition in Plants A given plant has about 30-40 elements and Plant Kingdom as a whole has 70 elements. Sachs and Knops discovered some of the essential elements by water culture or Hydroponis experiments. To know the essentiality of mineral elements, Arnon and Stout proposed 3 critaria. They are 1. An essential element must be involved in growth and reproduction of plant. 2. Its functions should not be carried out by some other element. 3. The element must be involved in metabolism. By following these criteria, 17 elements were found as essential. They are C, H, O, N, P, K, Ca, Mg, S, Fe, Mn, B, Cu, Zn, Mo, Cl and Ni. The first 9 are Macro elements and the rest Microelements. C, H and O are frame work elements and nonmineral elements. They are absorbed as CO2 and H2O. without these there is no formation of organic substances. Nitrogen is absorbed mainly as NO2, and it is integral part of Porphyrin structure of Chlorophyll and Cytochromes and one of the major components of cell membranes, proteins, and nucleic acids. Phosphorus is a structural component of cell membranes, some proteins, nucleic acids and ATP. Potassium is required for ionic balance in the cell and helps in stomatal movement. Calcium is part of Middle lamellum and helps in cell division. Mg is activator of several respiratory and Photosynthetic enzymes and part of Middle lamellum and Chlorophyll. Sulphur is a component of amino acids methionine, Cystein and Cystine and Vitamins such as Biotin, Thiamine and Co.A. It stabilizes the structure of proteins. Fe is a part of cytochromes and needed for chlorophyll formation. Mn helps in photolysis of water and activator of IAA oxidase. Zn is activator of Carbonic anhydrase and needed for IAA synthesis. Cu is a part of Plastocyanin and cytochrome oxidase. Boran is required for pollen germination and helps in transport of photosynthates. Mo is a part of Nitrogenase and activator of Nitrate reductase. Chlorine is needed for photolysis of water and helps in maintaining the cationic and anionic balance in the cells. Entry of ions into the cytoplasm against concentration gradient by using ATP or energy is called as Active absorption. It was shown by using respiratory inhibitors such as Azide and Cyanide. In Active absorption ions are carried by carrier proteins of membrane known as Porter. They are uniporters which carry a single ion at a time (H+ ATPase, Na+ ATPase). Cotransporter carry 2 ions either in same direction (Symporters) or in opposite directions (Antiporters). Movement of ions against concentration gradient by direct usage of ATP is called as Primary Active Transport. In H+ ATPase pump it generates Proton Motive Force which is responsible for the movement of other ion against concentration gradient and it is known as Secondary Active Transport. The carriere such as Symporter is subjected to 3 conformational changes during secondary active transport. Rhizobium is used as biofertiliser in Legume crops, Azospirillum in cereal other than Paddy, Cyanobacteria like Nostoc and Anabaena and Pteridophyte Azolla in Paddy fields. Mycorrhizal fungi like Glomus are used as fert-

Amount of energy available in a substance is called as free energy. The amount of free energy present in a substance is called as Chemical potential. Water potential of a system is the difference between chemical potential of pure water (set as zero) and chemical potential of water of the system. This term was given by Slatyer and Taylor and measured in Bars or Mega Pascals. It is indicated with the symbol . It usually has negative value. Water moves from a region of higher to a region of lower . Its components are Osmotic potential, Pressure potential and Matric potential. The change in the of a system due to addition of solute is called as Osmotic or Solute potential ( or s). It always has negative value. The change in due to positive hydrostatic pressure is called as Pressure potential or Por P. It has positive value. It is zero in flaccid and plasmolysed cells. It is negative in open systems under tension. The change in due to adsorption of water to hydrophilic substances is called as Matric potential (m or T). It has negative value. The water potential of a system or solution is algebraic sum of pressure potential, osmotic potential and matric potential. = + P + T. In a normal living cell the influence of matric potential on the water potential is negligible. Hence the of a cell is + P. Diffusion of a solvent from a region of low concentrated solution to a region of high concentrated solution through semipermeable membrane is called as Osmosis. It is demonstrated by Thistle Funnel and Potato Osmoscope experiments. The pressure developed in a system due to entry of water is called as Hydrostatic pressure. Shrinkage of protoplast of a plant cell when kept in hypertonic solution due to exosmosis is called as Plasmolysis. In this state the P of

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9

SENIOR INTER

PHOTOSYNTHESIS

RESPIRATION

Enzymes are named on basis of..

ilizers in crops like Potato, Red gram, Soybeans, Wheat, Maize etc. which not only improve mineral uptake but also make the crops tolerant to water stress and pests. Mycorhiza increase Phosphorus uptake. Enzymes Enzymes are named on the basis of substrate name, type of reaction and both (Succinate dehydrogenase). IUB system of enzyme classificatioin has 6 classes with sub classes, sub-sub classes and numbering in the sub-sub class. The classes are 1. Oxidoreductases (dehydrogenases, reductases, oxidases), Transferases (Transaminases, Kinases), Hydrolases (Phosphatases, Peptidases), Lyases, Isomerases and Ligases. Lock and Key model of Fisher, Paul Fields and Woods and Induced fit theory of Koshland best explains the mechanism of enzyme action. Enzyme activity is either reduced or totally hampered by agents or substances named as Competitive inhibitors (Malonic acid of Succinate dehydrogenase), Non-competitive inhibitors (Cyanide, Salts of heavy metals) and Allosteric inhibitors (end products of biochemical pathways or reactions. Photosynthesis Chloroplast of green cells is involved in this process. Thylakoids carry out light reaction & stroma dark reaction of photosynthesis. Thylakoid membranes have photosynthetic pigments, e-carriers. Pigments are organized as Photosystems which have a reaction centre with specialized chlorophyll a molecule as P700 (PSI) or P680 (PSII) and surrounding it the LHC with different photosynthetic pigments. LHC absorbs photons and transfers them to RC by inductive resonance where it is converted as excitation energy used for the transfer of electrons among various electron carriers. Chlorophylls (Chl.a-C55H72O5N4Mg, Chl.bC55H70O6N4Mg), Carotenes (C40H56), Xanthophylls (C40H56O2) and Phycobilins are the photosynthetic pigments. Only visible light is absorbed in photosynthesis. Red light is absorbed more and least absorbed one is Green light. A pigment molecule (P700 or P680) is in excited state for 10-9 S. Robert Hill showed the liberation of O2 from isolated illuminated chloroplasts in the presence of Potassium Ferric oxalate (Hill reagent). Liberation of O2 from water was shown by Ruben et.al by using O18 isotope. Decrease in photosynthetic rate when a green organism is exposed to longer wavelength of red light (>680nm) is called as Red drop. Increase in Photosynthetic rate when the organism is subjected to both longer and shorter (<680) wavelengths of red light is called as Emersons enhancement effect. From this Emerson concluded that two Photosystems (PSI and PSII) are operated in Photosynthetic light reaction. PSI is present in non-appressed regions of grana thylakoids and stroma thylakoids, has P700 as reaction centre, LHC has 100 chlorophylls with chl a and chl b in 4:1 ratio, has more carotenes and absorgs longer wavelength of red light. PSII is mainly present in appressed regions of grana thylakoids and a little in non-appressed regions, has P680 as its reaction centre, LHC has 250 chlorophyll molecules with Chl a and Chl b in 1:1 ratio, rich in xanthophylls and absorbs shorter wavelength of red light. Light reaction has both Cyclic and Non-cyclic electron transport. Non-cyclic electron transport was given as Z scheme by Hill and Bendal which involves both PSI and PSII. Absorption of light is first step in photosynthesis. PSII reduces the Cytochrome b/f complex and PSI oxidizes it. During Non-cyclic electron transport, by absorbing 2 photons by PSII and 2 by PSI, the 2 electrons or a water molecule are carried to NADP+ via Oxygen evolving complex, P680, Pheo, Plastoquinone, Cytochromeb/f complex, PC, P700, Fe-S protein, Fd to form NADPH + H+. During this 2 H+ of water and 4 H+ of stroma (through PQ cycle)are accumulated in lumen of thylakoid. This e- transport is inhibited by DCMU. In Cyclic e- transport discovered by Frankel in Rhodospirillum rubrum, only PSI is involved. The e- liberated from P700 reach the same P700 after passing through Fd, Cytochrome b6, PQ, Cytochrome f, and PC during which 2H+ of stroma are carried into lumen by PQ cycle operation. Photophosphorylation was discovered by Arnon. It is best explained by P. Mitchel's Chemiosmotic hypothesis. This theory states that formation of ATP in CF1 of CF is due to establishment of proton gradient across thylakoid membrane between stroma and Lumen during electron transport. For each 3 H+ carried through CF0 of CF there is formation 1 ATP in CF1. If 6 molecules of water is involved in non-cyclic electron transport, there is accumulation of 72 H+ in lumen which results in the formation of 24 ATP. NADPH + H+ and ATP formed in light reaction are used for the assimilation of CO2 into carbohydrates (Sucrose or Starch) in dark reaction. Hence the chemical energy is called as Assimilatory Power. CO2 is fixed during dark reaction through C3, C4 and CAM pathways by using ATP and NADPH formed in light reaction. It takes place in the stroma of chloroplast. The intermediates of C3 cycle in a swquence are 1. PGA (Rubisco), 2. BPGA (Kinase), 3. GAP (Dehydrogenase), 4. DHAP (Isomerase), 5. FBP (Aldolase), 6. FMP (Phosphatase), 7. EMP and XMP (Transketolase), 8. SBP (Transaldolase), 9. SMP (Phosphatase), 10. RMP and XMP (Transketolase), 11. RuMP (Epimerase) and 12. RuBP (Kinase) and has 13 reactions. Sucrose is formed in Cytosol and Starch in Chloroplast stroma. For the fixation each CO2, 2 NADPH and 3 ATP are used. Though Malate formation in C4 cycle was first noticed by Kortschak, Hartt and Burr, the reactions of this cycle were described in detail by Hatch and Slack in Sugarcane. It is also known as carboxylaton pathway and Hatch Slack cycle. C4 plants show Kranz (Garland) Anatomy with chloroplasts in both mesophyll and bundle sheath cells of its leaves. Primary carboxylation takes place in Mesophyll cell cytosol and Malic acid and PEP are formed in the chloroplast stroma. Calvin cycle and Pyruvate formation take place in Bundle sheath cell chloroplast. For formation of 1 Hexose, 12 NADPH and 30 ATP are used. C4 plants are more efficient than C3 plants. Light induced CO2 liberation in green cells of C3 plants is called as Photorespiration. It is also known as C2 cycle and Glycolate pathway. Chloroplast, Peroxisomes (usage of O2) and Mitochondria (liberation of CO2) are involved in this metabolism. NADH and ATP are used. 10% of the fixed carbon is lost as CO2. 75% of carbon of Glycolate is recovered as PGA. The various intermediates formed are PGA, Phospho Glycolic acid, Glycolic acid (Chloroplast), Glyoxylate, Glycine, Hydroxy Pyruvic acid, Glyceric acid (Peroxisome) and Serine (Mitochondria). Respiration Each ATP, upon hydrolysis,releases 7.6 K.cal. of energy. Cellular respiration is of 2 types known as Aerobic respiration & Anaerobic respiration. The overall aerobic respiration can be represented in the form of a simple equation as C6H12O6 + 6H2O + 6O2 6CO2 + 12H2O + 686 K.cal. Both cytosol and mitochondria are involved in this process and has 4 stages, 6 oxidation reactions, 3 decarboxylation reactions and 3 substrate level phosphorylation reactions Glycolysis is conversion of a molecule of Glucose into 2 molecules of Pyruvic acid through 10 biochemical reactions. It was discovered by Embden, Maherhof and Paranas. O2 is not required for this process. Net energy gain of this process is 2NADH2 and 2ATP. The formed pyruvic acid is transported to mitochondrial matrix by Pyruvate translocator. 2 PA is oxidatively decarboxylated to 2 Acetyl Co.A by dehydrogenase complex. In this 2 NADH2 and 2 CO2 are formed. It requires NAD,TPP, FAD, Lipoic acid, Co.A and Mg+2. Krebs cycle is oxidation of Acetyl Co.A into CO2 and release of more energy by using water in mitochondrial matrix through 10 reactions. It is also known as Amphibolic pathway, citric acid cycle, Oragnic acid cycle and Tricarboxylic acid cycle. It has 4 oxidation, 2 decarboxylation and 1 substrate level phosphorylation reactions. When 2 Acetyl Co.A are oxidized through Krebs cycle, there is formation of 6 NADH2, 2 FADH2 and 2 ATP. ETS is the 4th stage in aerobic respiration operated in the inner membrane of mitochondrion and coupled to ATP generation in Oxysomes by consuming oxygen (Oxidative phosphorylation). In this Complex I, II, III, IV, UQ, cytochrome C and Oxygen are involved When 1 Glucose is oxidized, there is removal of 128 H+ from matrix and transport of 104 H+ into perimitochondrial space. The above transported protons are energy rich and energy present in them is used for ATP generation in Oxysomes during Oxidative Phosphorylation. This ATP generation occurs as per Chemiosmotic theory of P.Mitchel. 3H+ are transported for generation one ATP. 3ATP are formed during oxidation of each matrix NADH and 2 ATP during oxidation of glycolytic NADH and Succinate to Fumarate conversion. In this way during oxidation of a molecule of Glucose in aerobic respiration, there is formation of 32 ATP in Oxysomes, 4 ATP in Cytosol and 2 ATP in matrix. The net gain of ATP is 36 because 2 ATP are consumed in Glycolysis Only about 40% of energy present in a molecule of Glucose is trapped as ATP and the remainder is lost as heat. It is partial oxidation of glucose into CO2 and Ethyl alcohol and liberation of 56 K.Cal of energy without using oxygen. It is operated in the cytosol and has Glycolysis and Fermentaion stages. Fermentation has 2 reactions. 1) Pyruvic acid is decarboxylated to Acetaldehyde by decarboxylase and 2) Acetaldehyde is reduced to Ethyl alcohol by dehydrogenase by using the 2 glycolytic NADH. The net gain of ATP in anaerobic respiration is 2. It is ratio between the volume of CO2 liberated to volume of O2 consumed in respiration. It is measured with Ganong's respirometer and indicates the type of substrate oxidized in respiration. R.Q for fats is around 0.7 (0.7 for Triolein and

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10

SENIOR INTER

NITROGEN METABOLISM

GIBBERELLINS

Chain termination takes place when..

Tripalmitic acid and 0.71 for Oleic acid). For Proteins it is 0.8 to 0.9. For organic acids it is more than 1 (1.33 for Malic acid, 1.6 for Tartaric acid and 4 for Oxalic acid) it is 1 for carbohydrates. Nitrogen Metabolism Transport of N2 from atmosphere to soil and from soil to atmosphere through plants, animals and microorganisms is called Nitrogen cycle. It has 1. Nitrogen fixation, 2. Nitrogen assimilation, 3. Ammonification, 4. Nitrification and 5. Denitrification stages Nitrogen fixation is conversion of N2 into NH3, NO2 and NO3. It has two types 1. Physical nitrogen fixation and 2. Biological Nitrogen fixation. In BNF, Nitrogenase converts N2 to 2NH4- by using 8H+, 6e- and 16ATP. In this Pyruvic acid supplies e- and H+ and Ferridoxin acts as electron carrier. During root nodulation in Legumes, Rhizobia chemotactically (Sugars, Aminoacids, Falvanoids) move towards roots, multiply, cause Shepherds crooke of root hair, dissolve cell wall of root hair, enter into root hair by the invagination of plasma membrane of root hair as infection thread, harbor in root cortical cells, become bacteroids, promote leg haemoglobin formation and ultimately hyper growth of root cortex that externally appears as root nodule. Usage of absorbed NO3- to form organic nitrogenous compounds such as proteins by plants is called as Nitrogen assimilation. Liberation of NH3 from organic nitrogenous substances of plant and animal dead bodies and their excreta by the action of Bacillus species is called as Ammonification. Conversion of NH3 into NO2- by Nitrosomonas and later to NO3- by Nitrobacter is called as Nitrification. Liberation of N2 from NO3- by species of Thiobacillus, Pseudomonas and Micrococcus is called as Denitrification. The chemical language on mRNA in the form of Nucleotide sequence to indicate amino acids to form proteins is called as Genetic code. It has 64 codons (61 sense codons and 3 Nonsense codons). It is triplet code, degenerate, continuous, non-overlapping, non-ambiguous, universal, has Start codons as AUG or GUG and Stop codons as UAA, UAG and UGA. Proteins synthesis is an integral part of Nitrogen assimilation and has 2 stages Transcription and Translation. Transcription is formation of mRNA on DNA strand by the action of RNA polymerase. It takes place by copying process in the nucleus. In Eukaryotes the formed mRNA (hnRNA) is subjected to processing by spliceosomes and later released into cytoplasm. Translation is arrangement of amino acids by tRNA in a sequence on ribosomal surface according to information on mRNA and formation of peptide bonds between them to form proteins. It has stages known as 1. Activation of Amino acid and its transfer to tRNA, 2. Chain initiation, 3. Chain elongation and 4. Chain termination. Aminoacids are activated and attached to tRNA by using 1ATP for each amino acid in the presence of Aminoacyl RNA synthetase. Chain initiation requires Ribosme, Factors IF3, IF1, IF2, GTP, mRNA, tRNAfmet. In this, IF3 attaches to smaller subunit of ribosme. Later IF1 attaches to it. In the mean time GTP and IF2 are associated which in turn attached to earlier formed complex to form s.subunitIF3-IF1-IF2-GTP comlex. To this mRNA is attached and later tRNAfmet is attached. Now the larger subunit of ribosme is attached during which GTP is hydrolysed to detach the IF factors. In this way initiation complex is formed. tRNAfmet occupies P site of Ribosomal large subunit. In Chain elongation, for the addition of each amino acid to the first amino acid 2GTP are used and there is role of EFT, EFG and Peptidyl transferase. By using 1 ATP, EFT brings the 2nd Aminoacyl tRNA to the A-site of ribosme and attaches to it. Peptidyl transferase breaks the bond between f.met and tRNA of Psite and establishes peptide bond between the carboxylic group of formyl met. and amino group of second aminoacid at A-site. As a result aminoacyl tRNA of A-site becomes Peptidyl tRNA. Now the Peptidy tRNA is shifted from A-site to P-site of Ribosome by EFG by using GTP due to movement of Ribosome a codon distance towards 5' end of mRNA. In this way the remaining amino acids are attached one after the other till a non-sense codon is exposed at A-site. Chain termination takes place when a nonsense codon such as UAA or UAG or UGA is exposed at A-site. These non-sense codons are recognized by R1 or R2 factors. These factors in turn recognized by R3 factor. In the process Peptidyl transferase detaches the Polypeptide chain from last tRNA at P-site and eventually the ribosomal subunits. mRNA and tRNA too are detached. Plant Growth and its regulators - Auxins Darwin confirmed the ideas of Sachs by demonstrating downward movement of organ forming substances from coleoptile in Canary grass in his book 'The Power of Movements in Plants'. Boysen-Jensen and Paal's experiments supported it. Went gave Bioassays for Auxins as Avena curvature test. Auxins are formed from Tryptophan. Zn is essential for auxin synthesis. Shoot apices are main centres of Auxin synthesis. Its transport on to promote fruit ripening and uniform senescence with decrease Nicotine content in Tobacco leaves. Photoperiodism Influence of day length on flowering is called as Photoperiodism. It was discovered by Garnar and Allard in Maryland mammoth variety of tobacco. Minimum photoperiod required to induce flowering is called as Critical day length. It is usually 10-14 hrs. Nicotiana, Soybean, Chrysanthemum are SDP, Spinach, Beet root are LDP and Cucumber, Maize are DNP. Vernalisation Induction of early flowering in certain plants by giving cold treatment to seeds or young shoots is called as Vernalisation (Lysenko). In annuals it is secondary for flowering and in biennials it is primary. Biennials are made to flower in the first year itself by cold treatment which reduces the vegetative growth of the plant. Model Questions 1. If in a unit area of leaf there are 500 epidermal cells, 1500 mesophyll cells and 20 stomata, the stomatal index of the leaf is 1) 0.04 2) 0.004 3) 0.03 4) 0.05 2. The phenomenon of inductive resonance is involved in the transfer of energy from 1) PS II to PS I 2) P680 to Pheo 3) PC to P700 4) -carotene to P700 3. The total number of matrix protons transport through complex I during aerobic breakdown of a molecule of glucose is 1) 32 2) 40 3) 16 4) 24 4. [A]: Genetic code is degenerate. [R]: Methionine has more than one codons. 1) Both A and R are true and R is the correct explanation of A 2) Both A and R are true but R is not the correct explanation of A 3) A is true but R is false 4) A is false but R is true 5. Choose the correct statement 1) All flowering plants require certain photoperiod exposure for flowering 2) All seed plants require cold treatment for preparing the plant for flowering 3) Vernalin is activated after cold treatment 4) Vernalin is formed after cold treatment Key: 1) 1; 2) 4; 3) 1; 4) 3; 5) 4 Plants and Human Welfare Crop Improvement SYNOPSIS 3 to 5 questions can be asked from this. This is also one of the important chapters with lot of applications. Much attention is required

is polar in both Acropetal and Basipetal manner in 1: 3 ratio. IAA, PAA and 4-chloro IAA are natural Auxins. NAA, IBA, 2,4-D and 2,4,5-T are synthetic auxins. Auxins promote Cell elongation, Xylem differentiation, Root initiation, Tropic movements (Phototropism and Geotropism), Apical dominance, Parthenocarpy and Female flower formation in Cucurbits. In Agriculture and Horticulture auxins (IBA, IAA, NAA) are used for root initiation and dicot weed control (2,4-D and 2,4,5-T). Gibberellins GA is diterpene and formed from Acetyl co.A. GA12 and GA22 are C-20 GAs and GA3 and GA20 are C-19 Gibberellins. Its transport is non-polar. GAs remove genetic dwarfism, promote seed germination, bolting, flowering, parthenocarpy and male flower formation. GAs are used in Grape gardesn to increase productivity and quality of grapes. They increase flower formation in Roses, Rhododendrons and Poinsettias. Cytokinins CKs are formed from AMP and Isopentyl pyrophosphate. These are mainly formed in roots and their transport is polar. CKs promote Cell division, Cell elongation in leaves, Morphogenesis, delay in senescence and stomatal opening. These are used in Agriculture and Horticulture to increase the shelf life of Spinach, Asparagus and Vase life of flowers. Abscissic acid ABA is sesquiterpene and formed anabolically from Acetyl co.A and catabolically from carotenoids. It is rich in dormant seeds and senescent leaves and mainly synthesized in mature leaves. Its movement is non-polar. It is absent in bacteria. ABA promotes dormacy in buds and seeds, closure of stomata, formation of perennating buds and leaf senescence. It prevents sprouting of potatoes during storage and minimizes transpiration. Ethylene It promotes fruit ripening, Triple response growth (Stem elongation prevention, Lateral growth stimulation, induction of transverse geotropism), delays or prevents flowering but promotes flowering in Pine apple. In Agriculture it is used in the form of Eheph-

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11

SENIOR INTER

GENETIC ENGINEERING

TISSUE CULTURE

Mutations were discovered by..

while reading this topic It is also known as plant breeding. The various methods that are commonly used are 1. Introduction, 2. Selection, 3. Hybridization, 4. Mutational breeding and 5. Polyploidy breeding. Introducing a plant into a new locality from its growing locality is called as Introduction. It is fastest, simplest and easiest method which doesn't require scientific knowledge and skill. Introduced plant serves as Germplasm bank and can be used directly in Agriculture Selection is the oldest plant breeding method and basis for crop improvement. It is of 3 types called Mass selection, Pureline selection and Clonal selection. Choosing the plants with desirable characters from a mixed population and collecting the seed from them to raise the crop in the next year is called Mass selection. It has been practiced by farmers. It improves the yield and quality of the crop. It is applicable to cross pollinated crops and the variety is in heterozygous condition. It takes 8 years for the development of a variety. It is the easiest of all selection methods which does not require Scientific knowledge. Dharwar American, Dodahatti local and Cambodias varieties of cotton and Pusa Moti of Bajra are developed by this method. Developing and choosing the purelines with desirable characters for cultivation is called as Pure line selection. It was first developed by Johannsen in Phaseolus vulgaris. It is applicable to self pollinated crops. All individuals are phenotypically and genotypically same and homozygous. It takes 10 years time for the development of a variety. Ground nut varieties TMV-3, RSB-17 and Paddy varieties CO-4,6,10, 14 are developed by this method. Developing and choosing desirable clones for cultivation is called as Clonal selection. It is applicable to vegetatively propagated crops. Individuals of a clone are heterozygous and phenotypically and genotypically same. It takes about 9 years time for development of a clone. Kufri Red, Kufri Safed varieties of Potato and Mundapa Peddaneelam Mango variety are developed by this method. Hybridization is cross between genetically unlike parents with desirable characters. It is the most important method which causes much genetic variability. Hybridization method has a series of steps that include Selection of Parents, Emasculation, Bagging, Artificial cross pollination, raising F2 generation plants, Improving and multiplication of F2 generation and distributing the seed to farmers. By this method several desirable characters can be incorporated into a single variety and usually the hybrids show vigour which is exploited for the improvement of Crops. Hybrid vigour is superiority of the hybrid over its parents in having desirable characters. It was first discovered by Kolreuter and the term Heterosis for this was given by Shull. Presence of more dominant genes and Heterozygosity are the two main reasons for Hybrid vigour. Mutations were discovered by Hugo de Vriese in Oenothera lamarkiana. Exploiting desirable mutations for the improvement of crops is called as Mutationla breeding. Experiments on Drosophila by Muller and on Barley by Stadler by using X- rays laid foundations for mutational breeding. It is the quickest method to bring genetic variability in the crop variety. UV, X, , and rays are physical mutagens. The chemical mutagens are Colchicine, Formaldehyde, EMS and Maleic hydrazide. Disease resisance in IR-8, Winter hardiness in Sweedish variety of Barley and Aruna variety of Castor are developed by Mutational breeding. Utilisatiion of Polyploidy for the improvement of crops is called as polyploidy breeding. Genetic Engineering Genetic engineering is a laboratory technique of gene manipulation. This method has various steps such as Isolation of gene from donor organism (treating the cells with cell wall degrading enzymes, protoplasts subjecting to detergents, treating protoplasm with proteases, phenols and RNAases, gradient centrifugation of such treated protoplasm to separate genomic DNA by precipitation, Cutting the DNA into fragments by restriction endonucleases such as EcoRI, subjecgting DNA fragments to Gel electrophoresis to separate them and later identifying the desired gene by Southern blotting in which gene specific probes are used), Inserting the gene into vectors such as Plsmids (pBR 322, pUC 19, pUC 101) by using Restriction endonucleases and Ligases to form recombinant DNA, inserting the rDNA into host cell by transformation to get several copies of the desired gene (Gene cloning), and ultimately selecting the desired transformed cells by methods using probes (colony hybridization) or without using probes. In Plant transgenics Ti plasmid of Agrobacterium tumifasciens is used as Vector. Papaya resistant to ring spot, Bt cotton resistant to insects, Roundup soybean resistant to herbicide, Tomato resistant to Pseudomonas infection, Potato resistant to Phytophthora fungal pathogen, Bruise resistant tomato Flavr Savr, Golden rice with Vitamin A, male sterile Brassica napus and Basumati rice resistant to abiotic and biotic streses are developed due to Plant genetic engineering. Transgenic plants are used as bioreactors in molecular farming. Tissue Culture It is obtaining plants from cells or tissues or organs by growing them on artificial nutrient media in controlled conditions. It is based on the principle of cellular totipotency which was demonstrated by Steward in Carrot. The various steps are preparation of nutrient medium, Sterilisation of nutrient medium, Preparation of Explant, Inoculation of explant on to the nutrient medium, Incubation and acclimatization and transfer to normal conditions. Organic and inorganic nutrients, vitamins are dissolved in distilled water and pH is adjusted to 5.6-7 and if required Agar is added to make it solid or semisolid. Such medium is minimal medium. To this Auxins and Cytokinins are added for organogenesis. Such medium is filled into the flasks or tubes and plugged with non-absorbent cotton. The Explant is prepared by surface sterilization with detergent and later with sodium or calcium hypochlorite solution or aseptic seedlings can be obtained from seeds in minimal medium upon surface sterilization with 0.1% Mercuric chloride. Explant is inoculated on to culture vials in laminar air flow chamber and later transferred to culture room for incubation for 3-4 weeks. During incubation, plantlets from explat or plantlets via callus formation, or plantlets via embryoid formation or plantlets via callus and embryoid formation are obtained due to organogenesis by using Auxins and Cytokinins. The embryoids can be encapsulated by sodium alginate to form synthetic seed for storage and transport. Mushroom cultivation Mushrooms belong to order Agaricales of Basidiomycotina of fungi and can live as symbionts, saprophytes and parasites (Armillariella mellea which causes root rot in Apple and other forest trees, bioluminescent shows FoxFire phenomena and used in mines for light). Agaricus bisporous (white button mushroom), Vovariella volvacea (Paddy straw mushroom), Pleurotus sojar-caju (Oyster mushroom) and Lentinus edodes (Shiitake mushroom) are commonly cultivated mushrooms. Amanita phalloides (Death cap), A. muscaria (Fly Agaric) and A.virosa (Destroying angel) are poisonous mushrooms commonly called as Toad stools. Mushrooms have low carbohydrate and Fat content (diet to diabetics and people with high blood cholesterol), high protein content, amino acids Lysine and Tryptophan, vitamins Ascorbic acid, pantothenic acid, Vitamin B12, minerals P, K, Cu, Fe, high K to Na ratio and fibre content. Compost is prepared by using Paddy straw, cotton seed, Rice bran, urea, Gypsum. Good compost is dark brown, non-greasy, has 7-7.5 pH, 2.2% nitrogen content, 65-70% moisture and subjected to pasteurization for 2 days. In Spawning the spawn is spread over the compost beds and allowed for spawn running for 15-20 days at 70-80% humidity and 23270C temperature. In Casing, spawn run beds are covered with pasteurized soil and incubation is continued for 8-10 days. When the mushrooms appear from the beds, temperature is brought down to 16 ± 2oC and moisture is increased to 95%. The first mushroom crop appears in the third week after casing and crop production is continued for 10-12 weeks. Every crop comes in a span of 7-10 days. Mushroomsare harvested when they are in Button stage and each crop is called as Flush. Good growers obtain 10-15 kg of mushrooms per 100 kg of compost. Mushrooms can be eaten fresh or stored for a week at 5oC. They can be cleaned, washed, kept in cans with salt solution, cans are kept in boiled water, cans are sealed and dipped in cold water during processing for storage upto 6 months. Model Questions 1. By emasculation one can make 1) Monoclinous flower into diclinous flower 2) Diclinous flower to monoclinous flower 3) Monoclinous flower as pistillate flower 4) Monoclinous flower as staminate flower 2. Choose the correct match List - I List - II A) Interferon I) Insecticide B) Probe DNA II) Taipei C) Golden Rice III) Sensitive biological detector D) Baculo virus IV) Viral vaccine V) Host protein A B C D 1) V IV III I 2) IV III II V 3) V III I II 4) V III II I 3. The first plant developed through tissue culture has following morphological characters I. Involucel II. Storage roots III. Pedicellate flowers IV. Didynamous androecium 1) I, II, III 2) II, III, IV 3) I, II, IV 4) I, II, III, IV 4. Arrange the following components of SCP Methylophilous methylotropous in a sequence of their gradual increase in the amount. I. Lipids II. RNA III. -carotene IV. Carbohydrates 1) III, IV, I, II 2) III, II, IV, I 3) IV, III, I, II 4) III, I, IV, II Key: 1) 3; 2) 4; 3) 1; 4) 1

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JR. & SR. INTER

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QUICK REVIEW

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FINAL STRATEGY

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Morphology

Plants Root Morphological Character Fusiform storage roots Conical storage roots Napiform storage roots Fasciculated roots Single storage adventitious roots Epiphytic roots Photosynthetic roots Respiratory roots Parasitic roots. Root nodules Tendrils Thorns Hooks Phylloclades Cladode Bulbils Tuberous stem Runners Stolons Suckers Off-sets Rhizome Corm Stem tuber Bulb Tendrils Spines Phyllodes Scale leaves Reproductive leaves Trap leaves Terminal inflorescence Axillary inflorescence Intercalary inflorescence Simple raceme Compound raceme Simple Corymb Compound Corymb Simple Umbel Compound umbel Simple Spike Compound Spike Catkin Simple Spadix Compound spadix Heterogamous Head Homogamous head - ray florets Homogamous head - Disc florets Compound head Solitary cyme Simple cyme Helicoid cyme Scorpioid cyme Dichasial cyme

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Bacteria Economic Importance

Economic Importance Largest bacterium Ammonifying bacteria Nitrifying bacteria Nitrogen fixing bacteria Bioinsecticide Sunhemp retting Flax retting Tobacco curing Tea curing Gobar gas Acetone, Butanol Vinegar Lactic acid Propionic acid Ethanol Lysine Streptomycin, Cycloheximide Chloramphenicol Neomycin Kanamycin Amphoterican Oxytetracyclin Polymyxin B Bacitracin SCP Vector in genetic engineering. Crown gall of angiosperms Botulism Blight or Rice Angular leaf spot of cotton Citrus canker Wilt of Solanaceae plants Fire blight of apple Anthrax of Sheep Tuberculosis of man, dog and cattle Actinomycosis of cattle Vibriosis Dysentry in man Diphtheria Cholera Typhoid Pneumonia Leprosy Plague Gonorrhoea Tetanus Syphilis

Raphanus sativus Daucus carota Beta vulgaris Asparagus, Ruiellia, Dahlia Ipomoea batatus Vanda Tinospora, Trapa, Taeniophyllum Avicellina, Rhizophora, Jussiaea Viscum, Loranthus, Cuscuta, Rafflesia, Balanophora, Orobanche, Striga, Santalum album Fabaceae Stem Vitis, Cissus, Passiflora Bougainvillea, Duranta, Punica, Carissa Hugonia, Artabotrys Opuntia, Casuarina, Cocoloba Asparagus, Ruscus Dioscorea, Oxalis, Globba, Agave Bulbophyllum, Knol-Khol Oxalis, Hydrocotyle, Lippia Jasminnum, Nerium Mentha, Chrysanthemum Pistia, Eichhornia, Agave Zingiber, Canna Curcuma, Musa Colocasia, Amorphophallus Solanum tuberosum, Stachys tubifera, Helianthus tuberosus Allium, Lilium Leaf Pisum, Lathyrus, Gloriosa, Smilax, Nepenthes, Clematis Opuntia, Argemone, Euphorbia, Zizyphus, Acacia, Parkinsonia Acacia melanoxylon, Parkinsonia Casuarina, Zingiber, Allium, Ruscus, Asparagus Bryophyllum, Scilla, Begonia Nepenthes, Drosera, Dionaea, Utricularia Inflorescence Crotalaria, Croton Dolichos, Hibiscus Callistemon Crotalaria, Asparagus, Althaea Mangifera, Yucca Cassia, Gynandropsis Brassica oleracea var. botrytis, Pyrus malus Allium, Smilax Coriadrum sativum, Daucus carotus Achyranthes, Amaranthus Oryza Casuarina, Acalypha, Morus Colocasia, Amorphophallus, Lemna Cocos, Musa Tridax, Helianthus Chrysanthemum Vernonia Sphaeranthus, Echinops Hibiscus, Datura Bougainvilleae, Jasmine Hamelia Heliotropium, Solanum Ipomoea, Clerodendron Nerium

Bacteria Thiomargarita namibiensis Bacillus species Nitrosomonas, Nitrobacter Rhizobium, Rhodospirillum, Chlorobacterium, Clostridium Bacillus thuringiensis Clostridium butyricum Clostridium felcinium Bacillus megatherium Micrococcus Methanococcus, Methanobacillus Clostridium acetobutylicum Acetobacter species Lactobacillus delbruckii Propionibacterium Zymomonas mobilis, Thermoanaerobacter ethanolicus Corynebacterium glutamicum Streptomyces griseus Streptomyces venezuelae Streptomyces fradiae Streptomyces kanamyceticus Streptomyces nodosus Streptomyces rimosus Bacillus polymyxa Bacillus licheniformis Brevibacterium Agrobacterium tumifaciens Clostridium botulinum Xanthomonas oryzae Xanthomonas malvacearum Xanthomonas axonopodis pv.citri Pseudomonas solanacearum Erwinia amylovora Bacillus anthracis Mycobacterium tuberculosis Mycobacterium bovis Vibrio tetus Bacillus dysentriae Corynebacterium diphtheriae Vibrio cholerae Solmonella typhii Diplococcus pneumoniae Mycobacterium leprae Pasteurella pestis Neisseria gonorrhoea Clostridium tetani Treponema pallidum

SEVEN STEPS TOWARDS SUCCESS

Be strong in fundamentals.. Develop the techniques of application. On Penultimate day of Your Exam: Prepare a topic from first year and another one from second year and have a test from them with a minimum of 20 questions with a feeling that you are writing the final exam. Recollect the names of plants, numericals, characters of plants, biochemical reactions. On 29th May: Look at the condensed and short listed tables and points. Do not try to read the topic from the beginning from the text book. Look at only the highlighted ones. Do not be panic, if you are not able to recollect some of the points you read. On Examination Day: Look at the easily forgetting short-listed names and numericals.

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