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INTRODUCTION TO PLANTS Kingdom Plantae 28 Jan. 2013 Intro-Plants.ppt 1 Plants are different from animals! Be prepared to Journal… 28 Jan. 2013 Intro-Plants.ppt 2 Plants are different • Cell walls of cellulose – complex carbohydrate • Acquire energy by photosynthesis – Chloroplasts with chlorophyll a, b – Chlorophyll reflects green part of visual spectrum 28 Jan. 2013 Intro-Plants.ppt 3 Journal the following: • Different structural adaptations of plants? • Different life cycles in a plant: sporophyte vs. gametophyte 28 Jan. 2013 • How Plant life cycle is different than animal life cycles? • What is the good and bad about asexual propagation? Intro-Plants.ppt 4 Plants are different • Plant body – Shoot: stem (nodes, internodes), leaves, reproductive structures (flowers, cones, etc.);usually above ground – Root: usually below ground, in soil • Variations 28 Jan. 2013 Intro-Plants.ppt 5 Plant Body • Shoot system – – – – Stem & branches Leaves Nodes & internodes Reproductive structures • Root system – Primary roots – Branch roots 28 Jan. 2013 Intro-Plants.ppt 6 Plants are different • Plant body: Shoot & Root with vascular tissues Xylem • water & minerals UP Phloem • sap DOWN Cambium • cell division for xylem & phloem 28 Jan. 2013 Intro-Plants.ppt 7 Plants are different • Growth at meristems • Apical meristem • ”primary” growth (length) • Lateral meristem = vascular cambium • “secondary” growth (girth) 28 Jan. 2013 Intro-Plants.ppt 8 Plant Life Cycles are different Alternation of generations 28 Jan. 2013 Intro-Plants.ppt 9 Plants are different • Life Cycle = Alternation of generations. Sporophyte generation (diploid, 2n) Gametophyte generation (haploid, 1n) 28 Jan. 2013 Intro-Plants.ppt 10 Sexual Life Cycle • Generalized life cycle of sexually reproducing species. Fertilization Meiosis 28 Jan. 2013 Intro-Plants.ppt 11 Animal Life Cycle • Multicellular diploid Zygote, embryo, young (larva), adult • Unicellular haploid sperm or egg 28 Jan. 2013 Intro-Plants.ppt 12 Plant life cycle • Alternation of generations: • Diploid sporophyte • Haploid gametophyte multicellular sperm or egg 28 Jan. 2013 Intro-Plants.ppt 13 Plant life cycle Example: fern 28 Jan. 2013 Intro-Plants.ppt 14 Plant life cycle Example: flowering plant 28 Jan. 2013 Intro-Plants.ppt 15 Asexual propagation • Plants often reproduce asexually – – – – – runners, rhizomes, tubers roots form new shoots fragmentation (willow, privet, Forsythia) • Used by nurseries to propagate varieties – ornamental plants (roses, crepe myrtle) – fruit trees (apple, etc.) 28 Jan. 2013 Intro-Plants.ppt 16 Asexual propagation • Advantages: • One individual can reproduce • Copies a successful genome exactly! • offspring are clones of parent; • offspring expected to be as successful as parent • May be faster • no time for courtship, pollination, etc. 28 Jan. 2013 Intro-Plants.ppt 17 Asexual propagation • Disadvantages: • All offspring are genetically identical. • If environment changes, all are equally disadvantaged. • (Sexual reproduction produces variation in offspring. Mixes genes from two parents.) 28 Jan. 2013 Intro-Plants.ppt 18