Biol 2280 Lecture Notes - Anthophyta PDF

Biol 2280 Lecture Notes Introduction to Anthophyta 10-1 Most diverse phylum-350k species...

Biol 2280 Lecture Notes Introduction to Anthophyta 10-1 Most diverse phylum-350k species ANTHOPHYTA I. Basic description of Anthophyta 1. Vegetative form -varies widely , from tiny aquatic plants to trees - includes annuals , biennials , perennials - leaf shape varies widely : simple , lobed , compound - monopodial branching - e basal dicots not monophyletic group - ~ Comparing Monocots and Eudicots: stem and leaves (and flower parts) Plant Feature Monocots Eudicots Number of Cotyledons ↳ "seed leaf" 1 2 ↳ cot short for Leaf Venation parallel branched # - Type of Stele in Shoot atactostele eustele Arrangement of xylem and phloem in vascular bundle "monkey face" arranged in root Type of Stele in Root eustele protostele Cactinostele) Number of Flower Parts in 35 in 45 , 55 20 growth N/A common Biol 2280 Lecture Notes Introduction to Anthophyta 10-2 2. Secondary Growth in Stems alSyste. 2 late wood entibres a vessel elements 5. fibres 3. early wood. 6 vessel elements · wood heterogeneous (variation cambial derivatives). 4 vascular cambium in ray. 7 be 1 transverse o can parenchyma vessels often in · vary size/distribution across growth ring · diffuse - porus T * · ring porus Ray System be extensive · can quite vol · 17-20 % of wood by. * Engentia , radial In than in conifers general , parenchyma more numerous to 50 % wood vol. VS. 8-10 % in conifers - up. Chard ↑ fibres Anthophyta wood) - 20 xylem , t fibres Coniterophyta (soft wood) - 20 xylem ,  Biol 2280 Lecture Notes Introduction to Anthophyta 10-3 3. The flower : determinante Shoot (modified for sex. reproduction) that bears sporophylls (modified leaves that bear sporangium) Sepals (calyx) leaflike typically green , e 20ecium candro is Petals (corolla) often coloured (visual attractant) amen a >sepacn perianth - calyx corolla + - both modified leaves pedicel ( > 1f) Stamen (androecium) filament + anther - modified microsporophylls - anthers contain multiple microsporangia Carpel (gynoecium) contains ovules ovary + style + stigma that bears ovules - modified megasporophyll Extensive diversification of floral forms through co-evolution w/ animal symbionts ↳ provide both pollen & nectar animals also facilitate seed dispersal may land plant life cycles evolutionary gradient across Angiosperms represent 1 end of an reduction ↳ reduction of gametophitic Biol 2280 Lecture Notes Introduction to Anthophyta 10-4 4. The Reproductive Cycle in the Angiosperms * how has reduction of the gametophyte generations occurred? ↑ gametophyte = embryo sac (7 cells , nuclei of 2 (3) cells when released from (anther gametophyte stamen = * where are antheridia and archegonia? (Development of megaspore - megagametophyte a. Megasporogenesis and megagametogenesis endicot mitosis ~ megasporangium mitos is there are (nucleus) 11 common - T types of development, the Polygonum 3 will degenerate 2 integuments > - megagametophyte type being the most common mitosis 7 cells - 8 nuclei + nucellus/ megasporangium mitosis fusion & mitosis > , 8 - 7 cells nuclei , polar nuclei 1 = 1N 1 = 3N  Biol 2280 Lecture Notes Introduction to Anthophyta 10-5 b. microsporogenesis and microgametogenesis microsporangia (pollen sacs) ⑳ ↑ % - each anther contains - microsporangiates w/in pollen sac - meiosis = microspores - 1 mitotic division = 2-cell structure (pollen) outer layer covered in sporopollenin burst - microsporangia open Pollen microgametophyte - immature - typically 3-pored synapomorphy - for eudicots - wall of: exine - of sporopollenin, cavities filled with proteins/ (enzymes), glycoproteins and lipids intine – made of cellulose and pectin Pollenation - transfer of pollen from anther to stigma · : Fertilization pollen tube grows - down thru into style into 1 ovule ovary > - tube thru micropyle > cell elongates generative cell 2 sperm nuclei ⑳inte a DOUBLE FERTILIZATION Polygonum type 1 : sperm nuclei + ↑ egg cell = In embryo - mutant twin > packed lunch - ↑ sperm nuclei + 2 polar nuclei = In endosperm Lilium : type sperm nuclei + 1 egg cell In embryo = ↑ sperm nuclei + 3n polar nucleus + In polar nucleus = In endosperm Biol 2280 Lecture Notes Introduction to Anthophyta 10-6 5. Modification of flower a. Symmetry ↑ plane of symmetry I I I - I S - I & & 1 - I I I - 12 S I - S I - I I I I derived basal Bilateral Radial = zygomorphic = actinomorphic Significance symmetry + fusion limits/control/filter pollenator access coevolution b/w flower a pollenator righter - Biol 2280 Lecture Notes Introduction to Anthophyta 10-7 F b. Fusion between whorls -connation - fusion b/w parts of the same whorl fusion ↑ structural integrity Fusion of gynoecium By 3-lobed Stigma NTY 3 stigmaat Il "style ( ⑳ ---hamber 3-lobed ovary 'receptacleIl P A B C carpel versus pistil A = no fusion - 1 carpel = 1 pistil B/C fused w/3 carpels = carpels - ↑ compound pistil How to determine ? transverse section of ovary - locules chambers ovary - = carpel fusion ↑ protection of ovules ovules - Biol 2280 Lecture Notes Introduction to Anthophyta 10-8 -adnation - fusion b/w floral whorls stamen/petal fusion common sepals/pedals/ filament fusion also common &. creates distinct floral tube hypanthium = - protects ovary If can shift apparent position of ovary - relative to other whorls located above other superior ovary - ovary hypanthium many whorls or - fixed to ovary inferior ovary - hypanthium to be located ovary appears below other whorls c. position of the ovary relative to other floral parts superior superior half inferior inferior complete adnation/fusion - of ovary to hypanthium hypanthium (presence off Biol 2280 Lecture Notes Introduction to Anthophyta 10-9 d. Ovary: ovule position and development into fruits where ovules placenta = attach to wall ovaries Parts of fruits of ovary endocarp - inner layer mesocarp - middle layer ovary walls [ swell + into develop fruit exocarp - outer layer e. Fruits - seed bearing structure that forms from the ovary sometimes also tissue accessory fruits - simple from 1 pistil (some w/ tissue accessory Eleshy drupe (peach) - hard pit (endocarp) berry (blueberry) - usually soft all way through specialized - hesperidium (Citrus) pepo (squash) try #ehiscent - legume (bean) - 1 carpel , opens along 2 sutures folicle 1 carpel 1 suture along - opens Andehiscent - acheue - seed attachment at 1 point Multiple fruits - multiple flowers i.. e pineapple Aggregate fruits - multiple pistils from same flower raspberry blackberry strawberry i.. e , , Accessoryfruits - Creceptacle hypantin is frompistt tissue accessory , strawberry - receptacle pineapple - receptacle  Biol 2280 Lecture Notes Introduction to Anthophyta 10-10 Fruit Classification The structure known as a "fruit" is found only in the members of the Angiosperms. A fruit developed solely from the ovary and its contents is known as a true fruit. A fruit developed from the ovary and its contents plus additional parts of the flower such as the receptacle, petals, and sepals is known as an accessory fruit (e.g. pineapple). The following is a common classification of fruit types. (see pp. 489-493 in Plant Systematics, 2nd ed., for additional information). I. Simple Fruits - Fruits formed from 1 pistil. They may be either true or accessory fruits. A. Dry Fruits: - Fruits in which the coat becomes dry at maturity. 1. Dehiscent Fruits - Dry fruits which at maturity open by definite natural means to shed the contained seeds. i. Legume A dry dehiscent fruit developed from 1 carpel and at maturity splitting along both the dorsal and ventral sutures. (beans, peas). ii. Follicle A dry dehiscent fruit developed from 1 carpel and at maturity splitting along only one suture. (larkspur, columbine) iii. Capsule A dry dehiscent fruit developed from several carpels. (a) Loculicidal capsule - one which splits along the outer median line. (lilies). (b) Septicidal capsule - one which splits along the septa and opens at the top. (yucca, agave). (c) Silique - a special long slender capsule of 2 carpels. (mustards). (d) Silicle - a special short broad capsule of 2 carpels. (mustards). (e) Pyxis - a capsule which has circumscissle dehiscence. (plantain, amaranths, purslane). (f) Poricidal capsule - one which opens with round holes. (poppies). Biol 2280 Lecture Notes Introduction to Anthophyta 10-11 2. Indehiscent fruits - Dry fruits which do not open when mature to shed their seeds. Many of this group are one seeded fruits. i. Achene - A one-seeded, dry, indehiscent fruit; the one seed is attached to the fruit wall at a single point. (buttercups, dandelion, sunflower). ii. Nut - A dry, indehiscent, one seeded fruit similar to an achene but with the wall greatly thickened and hardened. (beech, chestnut, oak, hazel; walnut and hickory - note: because of extrafloral bracts, or "husk", the latter two fruits are sometimes called "drupes"). iii. Samara - A one- or two-seeded dry, indehiscent fruit in which part of the fruit wall grows out into a wing. (elm, maple, ash). iv. Grain - A one-seeded dry, indehiscent fruit in which the fruit wall and the seed coat are fused. (wheat, corn, grasses). v. Schizocarp - A fruit formed from several carpels, each carpel of this pistil enclosing a single ovule, at maturity the carpels separate as separate indehiscent fruits. (mallow, wild carrot, dill). B. Fleshy Fruits - A fruit in which the wall becomes soft and fleshy as it matures. 1. Drupe - A one-seeded simple fruit developed from a superior ovary in which the innermost portion of the wall (endocarp) becomes hard and stony, the outermost part (exocarp) becomes a relatively thin skin, and the middle portion between the skin and the stone (mesocarp) becomes either fleshy or fibrous. (cherry, coconut, walnut and hickory - note: because of extrafloral bracts, or "husk", the latter two fruits are sometimes called "drupes", but best called "nuts"). 2. Berry - A simple fruit in which the ovary wall or at least its inner portions become enlarged and usually juicy. (grape, banana, gooseberry). Two special types of berry-like fruits may be singled out for special consideration. (a) Hesperidium - This is a special type of berry in which a leathery rind forms; the interior of the fruit divided by septa, indicating the number of carpels. (citrus). Biol 2280 Lecture Notes Introduction to Anthophyta 10-12 (b) Pepo - This is a special type of berry in which a relatively hard rind is formed; the interior of fruit not divided by septa. (watermelon, gourds, squash). 3. Pome - An accessory fleshy fruit formed by a group of carpels more or less firmly united with each other and surrounded by and united to the floral tube or receptacle. (apple, pear, mountain ash). II. Aggregate Fruit - A fruit formed by the development of a number of pistils from the same flower. The individual units may be berries or other specific types. (raspberry, strawberry). III. Multiple Fruit - A fruit formed by the development of a number of pistils often with accessory parts, the pistils being from a number of flowers. (mulberry, fig). Biol 2280 Lecture Notes Introduction to Anthophyta 10-13 Soybean life cycle · -: · 6 - · ! - - & ↑ · · W r o · J r · E n ↳ = + T ↳