Sexual Reproduction in Flowering Plants PDF

Reproduction in Plants | flowering ndroeeiwm paynom.nei.m.wn.feu.ieisa.im Embryo Development Apomixis 2- 2 Ofs.  NARO aecium. consist stamen of. I long I slender stalk...

Reproduction in Plants | flowering ndroeeiwm paynom.nei.m.wn.feu.ieisa.im Embryo Development Apomixis 2- 2 Ofs.  NARO aecium. consist stamen of. I long I slender stalk filament - Anther ( biwbed structure) ANTHER. Bilobed - Each lobe dithecous separated by longitudinal groove running lengthwise Microsporangium located at corners , two in each theca.  Structure of Microsporangium Microsporangium surrounded by 4 wall layers.. I. Epidermis 2. Endothecium middle layer }: Tapetum Protective Outer three layers dehiscence : release help in of anther to - Luellen grains. Tapetum provides nourishment to the developing pollen grains. tissue On young anther , sporogenesis forms the centre of each microsporangium. Microsporegeneris Process of formation of microspore from pollen mother cell ( Pmc) As development occurs in anther the , sporogenesis tissue undergoes meiosis to form microspore tetrad. cell tissue has Each of sporogenesis to tetrad capacity to giverise.  Hence , each cell is a potential pollen NCERTMagicwwT on PMC (pollen Mother Cell) Pollen Grain. or Represent gamete spherical Two layered EXINE Outer layer Hard layer Made of sporopollenin resistant Extremely Can withstand high temp , acidic , alkaline enzymes. , I NTI NE Inner layer Continuous layer Made and cellulose of pectin. Mature pollen grain contains two cells : - I. Vegetative cell : - Large with irregular nucleus contains food reserve 2 Generative cell in. : small I floats cell cytoplasm of vegetative.. shed In 60% of angiosperms , pollen grains at a - celled stage. mitosis On rest 40% - generative cell undergo celled to form 3 stage -. Viability pollen Grain 0 of.. Depends on temperature and humidity. * Ranges from 30 minutes to months -  GYNOECIUM. Represents of Reproductive part. be Apocarpous ( pistils free) May : syncarpous (pistils fused) 3 parts - style stigma Ovary Placenta contains megasporangium OVULES. Megasporangium Ovule attached to funicle by placenta HILUM. Junction of funicle and hilum -. Each ovule has 2 or 2 protective layers - INTEGUMENT (cover entire ovule encyst micropyle) chalaza : lies Basal on opposite side of micropyle : part of ovule. Nucellus : Present within integuments '. Contains Reserve food. located Embryo within sac nucellus or. female gametophyte  Megasporegenesis Megaspore mother cell ( MMC) converts into megaspores. Mmc - large contains dense - cytoplasm - prominent nucleus undergoes meiosis to form 4 megaspores. only 2 megaspore is functional other 3 - degenerate That one. develops into f gametophyte  Female Gametophyte I , SPO Ric Development : MONO nucleus of functional megaspore Divides mitotically 2 nuclei move towards opposite ends 2 more mitosis nucleate 8 Embryo sac Cf gametophyte) 6 nucleus : surrounded by cell wall Rem 2 egg apparatus ( polateei ) :. below Egg Apparatus : At micropylar end : 9. egg t synergies 2 synergies : filiform apparatus ( lead pollen tube Antipodal calls : ht chalazal end Typical of gametophyte 7 celled 8 nucleate  Pollination Process transfer of pollen grain from of anther to stigma. Autogamy xenogamy Transfer from anther Anther to to stigma of ' stigma of same flower different Geitonogamy.. vida plant Oxalis kinds Anther to produces 2 stigma of flowers of another - flower of same chasmogamous plant (engrossed) functionally icleistogamous cross pollination ( flowers don't but genetically open only self pollination -. Autogamy)  Pollination Agents of WIND WATER ANIMALS Most common. Rare Butterflies abiotic agent Bees pollen grains wasps used well exposed are like long , ribbon Flowers , stamen , protected. - large , large feathery - from wetting colourful , stigma by mucilaginous sheath. fragrant contain and nectar ovule to attract single. Vallisneria ( Pollen Rewards) flowers packed nydriua in inflorescence zostera. Amorphofphallus provide place to common in Majority of lay eggs. GRASSES. water plants I like -. Yucca plant water hyacinth its math water lily pollinated Insects by. Pollen grains are sticky  Pollen - pistil reaction is DYNAMIC. Prevention both I of autogamy geitonongamy DIOECY Nceepimagcleu is Double fertilisation pollen grains fall on stigma and pollen releases tube 20 enters one of synergies gametes. ( 2 P gamete + egg zygote syngamy) - 2 or gamete t polar - PEN (Triple fusion ) (primary nuclei Nucleus Endosperm ) Double fertilisation Two fusions : Post - fertilisation PEN → Endosperm zygote → Embryo Ovules → seed ovaries → fruit Rest → Degenerate  Embryo Development Embryo develops at micropylar end Pro Zygote → embryo Globyular → Heart - shaped Iv Embryo consists of : Mature Embryo Embryonal Anis cotyledon monocot ( s cotyledon) Dicot (2) Portion of embryonal ranis above level of cotyledons : Epicotyl contains plumule (shoot tip) Below level of cotyledons : HYPOCOTYL contains radicle ( root tip) MONOCOT - Embryo - I cotyledon SCUTELLUM : Root cap I radicle enclosed in COLEORRHIZA Shoot apex enclosed COLEOPTILE by  SEED. - Albuminous Non Albuminous Endosperm present. Endosperm absent WHEAT PEA MAIZE BEANS Black pepper : Remnant of Nucellus (called as PERI SPERM ) Dicot Monocot  f-suit Development Fruits may be fleshy : : mango Groundnut bug Sf fruits develop from ovary : true fruits Of developed from any other part : false Apple Strawberry , (Thalamus forms fruit) → Of fruits develop without fertilisation - Partnenocarpic fruits BANANA APOMIXIS Process seed formation without fertilisation of Form of Asexual Reproduction minuting sexual In Citrus and mango - Nucellus develops into embryo sac ( POLY EMBRYONY) Apomixis important for producing o : hybrid varieties of fruits T crop yield -. Previous yrs Impe.