1.FLOWER

2. Flowers Function Contain the sexualorgans for the plant. Produces fruit, whichprotects, nourishes andcarries seeds. Attracts insects forpollination. 3. Basic Flower Structure stigma carpel gynoeciumlocule styleFlower is perfectpollenFlower is monoeciousovuleovaryantherfilament stamen androeciumpetal corollareceptaclesepalperianthcalyxPerianth is complete pedicel 4. Parts of the Flower Sepals Outer covering of theflower bud. Protects the stamensand pistils whenflower is in bud stage. Collectively known asthe calyx. 5. Parts of the Flower Petals Brightly colored Protects stamen &pistils. Attracts pollinatinginsects. Collectively called thecorolla. 6. PetalPetals are used to attract insects into the flower, they mayhave guidelines on them and be scented.StigmaIs covered in a sticky substance that the pollen grains willadhere to.StyleThe style raises the stigma away from the Ovary todecrease the likelihood of pollen contamination. It variesin length. 7. OvaryThis protects the ovule and once fertilization has takenplace it will become the fruit.OvuleThe Ovule is like the egg in animals and oncefertilization has taken place will become the seed.ReceptacleThis is the flowers attachment to the stalk and insome cases becomes part of the fruit after fertilizatione.g. strawberry. 8. Flower stalkGives support to the flower and elevates the flower for theinsects.NectaryThis is where a sugary solution called nectar is held toattract insects.SepalSepals protect the flower whilst the flower is developingfrom a bud. 9. FilamentThis is the stalk of the Anther.AntherThe Anthers contain pollen sacs.The sacs release pollen on to the outside of theanthers that brush against insects on entering theflowers.Once the pollen is deposited on the insect..it istransferred to the stigma of another flower.The ovule is then able to be fertilized. 10. Male Parts Female PartsStamenPistil OvaryAntherStigma OvuleFilamentStylePollen 11. Parts of the Flower (Stamen) Male reproductivepart Anther Produces pollen Filament Supports the anther 12. Parts of the Flower (Pistil) Female reproductivepart Ovary Enlarged portion at baseof pistil Produces ovules whichdevelop into seeds Stigma Holds the pollen grains 13. Parts of the Flower (Pistil) Style Connects the stigma with the ovary Supports the stigma so that it can be pollinated 14. Parts of the Flower 15. 2 Types of flowers: Perfect vs. ImperfectImperfect- a flower that has either all male parts or all female partsEX: cucumbers, pumpkin, and melonsPerfect-a flower that has both male and female parts in the same flower EX: roses, lilies, and dandelions 16. Imperfect Flower Male or femalereproductive organsnot, but not both. Example: A male flower has sepals,petals, and stamen, butno pistils. A female flower hassepals, petals, andpistils, but no stamen. 17. Perfect Flowers Contains both maleand femalereproductivestructures. 18. Incomplete Flowers Missing one of thefour major parts ofthe flower. Stamen Pistil Sepal Petal 19. Complete Flowers Contains male andfemale reproductiveorgans along withpetals and sepals. 20. Some Example Stories:Perfect Flowers:Pea exclusively self-pollinatingHibiscus self-pollinating if not crossedCherry self-incompatible only outcrossesImperfect Flowers:Begonia unisexual but monoeciousHolly unisexual and dioeciousVariable: Cucumber male, perfect, female, parthenocarpic 21. Flowers Imperfect flowers are always incomplete but.. Perfect flowers are not always complete and.. Complete flowers are always perfect. 22. Importance of Flowers Important in florist & nursery businesses. Many plants are grown solely for theirflowers. Plants have flowers to attract insects forpollination, but people grow them forbeauty & economic value. 23. Important Flower Crops 24. Basic Flower Structure stigmacarpel Pistil is simplegynoeciumlocule styleFlower is perfect pollen Flower is monoecious ovule ovary anther superiorfilamentstamen Flower is hypogynous androeciumpetal corolla sepalperianthreceptacle calyxPerianth is complete pedicel 25. Ovary Superior Flower HypogynousOvary Half-Superior Flower Perigynous Ovary Half-Inferior Flower Epigynous Ovary Inferior 26. Basic Flower Structure stigmacarpel Pistil is simplegynoeciumlocule styleFlower is perfect pollen Flower is monoecious ovule ovary anther superiorfilamentstamen Flower is hypogynous androeciumpetal corolla sepalperianthreceptacle calyxPerianth is complete pedicel 27. NUMBER OF FLOWER PARTS Dicotyledonous: the flower parts are in multiplesof four or five; rarely are they in 3s Monocotyledonous: the flower parts are in 3sNATURE OF FLOWERS Regular: when members of each set of organs the sepals, petals, stamens and pistils are of thesame size and shape Irregular: when some members of one or moresets of organs are different in size or shape or both 28. Irregular Flowers Papilionaceous: the standard petal or banner,which is usually the largest and mostly showy ofthe petals is the outermost; the wings or alae aretwo lateral petals, the keels or carinae, which areusually the two smallest petals, are innermost. Caesalpinaceous: the standard petal, which isusually the smallest, is innermost; the four otherpetals, which are almost of the same size andshape, are called accessory petals. 29. Irregular Flowers Bilabiate or two-lipped: the petals are partiallyunited; the corolla lobes (the free ends of partiallyunited petals) from distinct upper and lower lips. Orchidaceous: the flower has three petals, one ofwhich is entirely different in size and shape and iscalled lip or labellum. 30. SYMMETRY OF FLOWERS1.Radial/actinomorphic: one that can be divided into two equal halves along any plane passing through the central axis.2. Bilateral/zygomorphic:one that can be divided only intotwo equal parts by a median vertical cut. 31. Ovary SuperiorFlower Hypogynous 1Ovary Half-SuperiorFlower Perigynous1Ovary Half-InferiorFlower EpigynousOvary Inferior1 32. TYPES OF INFLORESCENCETypes DescriptionSpike Axis elongate; floret sessile,becoming progressively youngertowards the apexCatkinInflorescence a spike, and partlycovered by a spatheRacemeAxis elongate; florets pedicellate,florets progressively becomingyounger towards the apexPanicle A branched racemeCymeAxis elongate ; florets in 3s, thecentral floret maturing ahead ofthe other two 33. TYPES OF INFLORESCENCETypes DescriptionCorymbInflorescence flat-topped, theflorets growing to the sameheightUmbel Axis greatly shortened; pedicelsof the same length appearing toradiate from a reduced axisHeadSessile florets gathered on a flatreceptacle; some plants withflorets differentiated into the rayand disc florets 34. LET US EXAMINE THE INTERNALSTRUCTURE OF A LILY OVARY AND ANTHER WITH POLLEN GRAINS 35. INTERNAL STRUCTURE Ovary wallFuniculus Locule 36. Ovule-Embryonic seed consisting ofintegument(s) or the protective cell layersurrounding the ovule and nucellus or(megasporangium) which undergoessporogenesis via meiosis Emrbyo sac-Female gametophyte Ovary wall- The ovary wall is the wall of the ovaryof a flower which eventually develops variouslymodified in the fruit wall or pericarp Funiculus-Stalk by which ovule is attached toplacenta Locule- Ovary cavity Ovary-Ovule-bearing part of pistil 37. plant structure that develops into a seed whenfertilized. In gymnosperms (conifers and allies) theovules lie uncovered on the scales of the cone. In angiosperms (flowering plants), one or more ovulesare enclosed by the ovary (portion of the carpel, orfemale reproductive organ). Each ovule is attached by its base to the stalk(funiculus) that bears it. A mature angiosperm ovule consists of a food tissuecovered by one or two future seed coats. 38. A small opening (the micropyle) in the integuments atthe apex of the ovule permits the pollen tube to enterand discharge its sperm nuclei into the embryo sac, alarge oval cell in which fertilization and developmentoccur. Variations in form and position of the ovule aresignificant in plant classification: orthotropous ovulesstand out straight into the cavity of the ovary;campylotropous ovules are at right angles to thefuniculus; anatropous ovules are directed back towardthe funiculus. Intermediate forms also occur. 39. TapetumPollen Sac 40. Pollen/Pollen grains- formed inside the anthers,which are specialized parts of the stamens Pollen sac- Each anther lobe contains twolongitudinal pollen sacs (or locules) withinwhich the pollen grains are produced. A singlevascular band extends from the filament into thecenter of the connective and continues into theanther. Tapetum-The sporogenous tissue is delineatedfrom the anther wall by a single-layer of cellsdesignated as the tapetum. The cells of thetapetum enlarge and develop a complexultrastructure, which indicates that they becomevery active metabolically 41. The process by which living organismsproduce their offsprings for the continuityof the species One of the most important characteristic ofall living beings. It is the production of onesown kind. The modes of reproduction vary accordingto individual species and availableconditions. 42. How are new plants formed?New plants can grow in several ways:from seeds (sexual reproduction)- offspring is created by fusion of haploid gametes, the egg and sperm cells - new individual differs geneticallyFrom Bulbs, tubers and other vegetative parts (asexual reproduction)- creation of new individuals whose genes all come from one parent without fusion of egg and sperm. - e.g Budding, fission, sporulation and etc 43. Sexual reproduction Flowers contain a plants reproductiveorgans. Most plants contain both male andfemale parts. Some plants have only male sex organs whileothers contain only female sex organs. The organs may even be separate on thesame plant (squash) 44. Sexual reproduction needs special sex cellscalled gametes. The advantage of sexual reproduction isthat it leads to genetic variation. If a species is varied it is more likely to beable to adapt to any changes in itssurroundings. 45. In a flowering plant the flower develops on the receptacle.The buds of the flower are protected by sepals. Sepals are small leaves. The petals of many flowers are brightly colored which attracts insects.These petals are often highly scented. Inside the flower there are pin-like structures called stamens. 46. The top of the stamen produces pollen or pollen grains,male gametophyte (microgametophyte). The club-likestructure is the stigma. Pollen is produced by meiosis of microspore mothercells that are located along the inner edge of the anthersacs (microsporangia). The tube cells (tube nucleus) develop to pollen tube. The germ cells divides by mitosis to produce two spermcells. Division of germ cell can occur before or afterpollination 47. In the base of the stigma is the ovary. The ovary containsovules. Each ovule contains a female sex cell. The carpel is made upof the stigma, style and ovary. When the tip of the stigma is sticky it indicates that thecarpel is ripe and ready to receive grains of pollen. Flowers differ in external colour, sizeand shape. However they all have asimilar internal structure. Some have carpels with oneovule, others have rows of ovules. 48. THANK YOU!!! 49. Cont... It may be simply by division of the parent cell as inunicellular organisms, by fragmentation of the parentbody, by formation of buds and spores,or it may bevery elaborate involving development of male andfemale reproductive organs (stamens and pistils).Irrespective of the mode of reproduction, allorganisms pass on their hereditary material to theiroffspring during the process of reproduction. 50. MODES OF REPRODUCTION The various modes by which plants reproduce are of three types (a) Asexual (b) Vegetative (c) Sexual 51. In Asexual mode of reproduction, offspring arereproduced from a vegetative unit-produced by aparent without any fusion of gametes or sex cells. A single parent is involved Offsprings are genetically identical to the parent.Asexual reproduction may be of the following types Fission : As in unicellular organisms like bacteria andyeast where the content of the parent cell divides into2, 4 or 8 daughter cells and accordingly the fission isknown as binary or multiple fission. Each newlyformed daughter cell grows into a new organism. 52. Binary fission in bacteria 53. Budding : A bud like outgrowth is formed on one side of the parent cell and soon it separates and grows into a new individual e.g. in yeast. 54. Fragmentation : In filamentous algae, an accidental breaking of the filament into many fragments, each fragment may give rise to a new filament of the algae by cell division e.g. Spirogyra. 55. Spore formation :In lower plants including bryophytes and pteridophytes, special reproductive units develop asexually on the parent body. These are called spores. They are microscopic and covered by protective wall. When they reach the suitable environment they develop into a new plant body e.g. in bread moulds, moss, fern. 56. Vegetative reproduction : involves formation ofnew plantlets from vegetative-(somatic) cell, buds or organs of the plant. Here, avegetative part of the plant (Root, stem, leaf or bud)gets detached from the parent body and grows into anindependent daughter plant.-It is similar to a sexual reproduction in that it alsorequires only mitotic division, no gametic fusion anddaughter plants are genetic clones of the parent plant. 57. Stems, roots, leaves and even buds are variouslymodified to suit this requirement. This is callednatural vegetative reproduction. Natural Method : In natural methods, a portion ofthe plant gets detached from the body of the motherplant and grows into an independent plant. The partsmay be stem, root, leaf or even flower. 58. Cont... The underground modification of stem, like rhizome, (in ginger), tuber (potato), bulb (onion) and corm (zamikand) are provided with buds which develop into a new plant Plants with sub-aerial modification such as Pistia (offset) and Chrysanthemum (sucker) are also used for vegetative propagation. 59. -tuberous roots (Asparagus and sweet potato) can alsobe used for propagation as these roots haveadventitious buds which ground into a new plant. 60. leaves contribute to propagation of plants leaves of Bryophyllum and Kalancloe have buds on the margin and these buds grow into small plantlets. When detached from the mother plant they grow into independent plants.Bryophyllum 61. Agave and Oxalis multicellular bodies called bulbils develop near the flower. These are called bulbils which when fall on the ground grow into new plant.Agave bulbilsOxalis 62. ARTIFICIAL METHODS Cuttings : Many plants like rose, Bougainvillea, Croton, Coleus, money plants, sugarcane etc. are grown through their stem cuttings. Cuttings of these plants can be grown even in water where they strike roots and develop adventitious buds. 63. Layering : In this method, a lower branch of a plant isbent down and covered with moist soil leaving thegrowing tip above the soil. A ring of bark is removed fromthe stem before it is bent down In a few weeks time whenenough roots have developed on the underground portionabove the ringed part, it is cut off from the parent plantand grown separately as an independent plant. Example: Jasmine, straw berry, grapevine, Bougainvilleaetc. 64. Aerial layering or Goatee is a similar practice where bending of branches isnt possible because of the height of plant or due to woody nature of stem. In this method a ring of bark is removed from a selected branch, and it is covered with moist moss and enclosed in a polythene sheet when roots appear, the stem is cut below the roots and planted to form a new plant. 65. Grafting : It is especially important for propagation of seedlessvarieties of plants. It consists of inserting a small branch into arooted plant. The rooted plant taken as a stock is resistant to disease and isphysically sturdy. In this stock a branch is inserted which is knownas scion or graft. This scion or graft is the stem cutting from thedesired plant. Usually the grafted end of stock and scion fit wellwith each other and are bound firmly with tape or rubber-banduntil their tissues unite and vascular continuity is established. Grafting is mostly practised in dicot plants. Grafting has beenfound extremely useful in propagating improved varieties ofvarious flowers and fruits like rose, Bougainvillea, Citrus, mango,apple etc. 66. Tissue culture 67. MICROPROPAGATION - The technique of plant tissuesculture is utilised for propagation of plants.-A small piece of tissue, organ or even a single cell is taken from aplant and is transferred to a sterilized container with nutrientmedium in aseptic conditions. The tissue grows very-very fastinto an unorganised mass, called callus.-The callus can be maintained and multiplied for an indefiniteperiod. When small portions of the tissue are transferred toanother specialised medium with hormones, it inducesdifferentiation and plantlets (little plants) are formed.-The plantlets can be transplanted into pots and or soil by agradual process and are grown to mature plants. 68. Advantages of micropropagation By this method an indefinite number of identicalplants can be obtained vegetatively starting from asmall amount of parent tissue. In orchids, carnations, Chrysanthemum andAsparagus, micropropagation is being successfullytried in some parts of our country. 69. ADVANTAGES AND DISADVANTAGESOF VEGETATIVE REPRODUCTION Advantages-Rapid means of reproduction and spread.- Offsprings identical to parent. The desired varietiescan thus be preserved genetically for use.-Food storage organs allow perennation or survival inadverse conditions.-Improved varieties of ornamental plants and fruit treescan be multiplied easily.- Vegetative propagation is a quicker, easier and a lessexpensive method of multiplying plants. 70. Disadvantages-Overcrowding and competition for space unlessseparated artificially.-New varieties cannot be produced by this methodexcept by mutation.- Diseases typical of the species are rapidly transmittedand can decimate a crop. 71. Sexual reproduction involves fusion of male andfemale reproductive cells-(gametes) which are haploid produced by male andfemale reproductive organs.-This fusion is known as fertilization and results inthe production of a zygote (diploid). Furtherdevelopment of zygote gives rise to a newindividual which is diploid. 72. REPRODUCTION IN ANGIOSPERMS(FLOWERING PLANTS) 73. Angiosperms reproduce both by vegetative as well asby sexual methods. In this section we will study thesexual reproduction in angiosperms. As you know sexual reproduction occurs by fusion ofmale and female gametes present in the flower. Thus flower represents the reproductive unit of aplant. Angiosperms can be classified as annuals, biennialsand perennials depending upon the time they take tocomplete the life cycle and flowering.(a) Annuals eg. pea(b) Biennials e.g. radish(c) Perennials e.g. mango, peepal, neem etc.(d) Monocarpic e.g. bamboo 74. Factors Affecting Flowering Flowering in a plant is affected by temperature(vernalisation) and light(photoperiodism).Vernalisation : Low temperature treatment whichstimulates early flower formation is calledvernalisation.Photoperiodism : It is the response in growth andflowering of a plant to the duration of light and darkperiod per day.Sex in flowers : (flower, inflorescence, fruit andfamilies), that flowers may be bisexual (having bothstamens and carpels) or unisexual (staminate orpistillate). 75. Angiosperms: Production of Male GametophyteStamen = filament + antherMeiosis inside anthermale sporesDetails follow 76. Angiosperms: Production of Male Gametophyte Meiosis in lily anther4 haploid daughter cells, also called pollen tetradsHaploiHaploid dHaploiHaploi 77. Angiosperms: Production of Male Gametophyte From the point of view of the plant life cycle, anther = male sporangium Each of the 4 pollen tetrads = spore Because of their small size, they are called microspores. HaploidHaploidPollen tetrads = microspores HaploidHaploid 78. Angiosperms: Production of Male GametophyteHaploiHaploid d As anther matures, 4 microspores of a tetrad separate from each otherHaploidHaploid nucleus of eachHaploimicrospore undergoes a singled mitotic division MitosisThe 2 resulting haploid nucleibecome encased in a thick,resistant wall, forming a pollengrain. Pollen Grain 79. Angiosperms: Production of Male GametophyteHaploiHaploiFrom the point of view of thed dangiosperm life cycle, a pollengrain is an immature malegametophyte, since it has beenproduced by the mitoticdivision of a spore.HaploidHaploid Mitosis Pollen Grain 80. Angiosperms: Production of Female GametophyteThe pistil (femalereproductive portion) iscomposed of the stigma,style, and ovary. 81. Angiosperms: Production of Female GametophyteAn ovary may contain a number of ovules.Meiosis takes place inside the ovules, resulting in the production of femalespores. Details follow 82. Angiosperms: Female GametophyteOnly one of the haploid spores resulting from meiosis in the ovulematures. It undergoes 2 rounds of mitosis to form the embryo sac,which has 8 haploid nuclei. Embryo sac = female gametophyte 83. Alternation of Generations: Angiosperms To complete the life cycle, the gametes produced by the male and female gametophyte must unite, restoring the diploid sporophyte. Female gametophyte = embryo sac Immature male gametophyte = pollen grain 84. Pollination : Transfer of pollen grains from the anther to the stigma of flower. 85. 1. Pollination by wind (Anemophily) : (Anemos : wind, Phile: to love)-example, grasses and some cacti.2. Pollination by insects (Entomophily) : (entomo : insect, phile : to love)-Salvia flowers show special adaptations for pollination by bees.3. Pollination by Water (Hydrophily) (Hydros : water)-e.g. Hydrilla, Vallisneria.4. Pollination by Animals (Zoophily) (Zoon : animal)-example sun bird, pollinates flowers of Canna, gladioli etc., Squirrels pollinate flowers of silk cotton tree. 86. CLEISTOGAMY 87. Fertilization and Embryo Formation Pollen grain landing on stigma of ovary pollen tube growth 88. Fertilization and Embryo Formation 2 haploid cells of pollen grain are called the generative cell and the tube cellPollen tube growing from apollen grain 89. Fertilization and Embryo Formation As pollen tube grows towards ovule, nucleus of generative cell divides by mitosis, producing 2 haploid sperm 90. Fertilization and Embryo Formation The pollen grain, along with the pollen tube containing 2 sperm, is the mature male gametophyte. 91. Fertilization and Embryo FormationPollen tube continues to grow,entering ovule through openingcalled the micropyle 92. Fertilization and Embryo FormationOne of the sperm fertilizes the egg, producing adiploid zygote. This zygote will divide anddifferentiate, forming the sporophyte plant.The angiosperm life cycle has been completed. The other sperm will fuse with the 2 central haploid nuclei in the embryo sac, producing a triploid nucleus.These events are called doublefertilization. 93. Fertilization and Embryo FormationTissue that develops from the triploid nucleus =endosperm. Energy stored in this tissue nourishes thedeveloping embryo. 94. Dont make me read, make me understand THANK YOU!!! 95. Flower Structure - review Ranunculus acris - buttercup 96. Flower Formula: Symbol Sequence to Diagram FlowerSymmetry: *=radial =bilateral* 5, 5, , 5Number of Parts per Whorl: sepals in calyx petals in corolla stamens in androecium carpels in gynoeciumFusion within whorl: curved line over numberFusion between whorls:square bracket below numbersAttachment of flower parts relative to ovary:horizontal line