Chapter 23: Plant Diversity and Life Cycles

Transcription

1 Chapter 23: Plant Diversity and Life Cycles Section 1: Introduction to Plants Cuticle: a waxy or fatty and watertight layer on the external wall of epidermal cells Spore: a reproductive cell or multicellular structure that is resistant to environmental conditions I. What is a Plant? A. Dominant groups of organisms on land B. Very diverse group C. Characteristics 4. D. Photosynthesis II. Establishment of Plants on Land A. Evolved from multicellular aquatic green algae B. Absorbing Nutrients C. Preventing Water Loss Cuticle D. Dispersal on Land Single cells allowed for plant dispersal Seed plants produce special kind of spore called pollen 1

2 Section 2: Seedless Plants I. Nonvascular Plants A. B. Reproduce by means of spores C. D. Water and nutrients transported by diffusion and osmosis Moves short distances and slowly E. Examples II. Seedless Vascular Plants A. Have vascular tissue but no seeds B. Grow larger C. D. Examples Section 3: Seed Plants Gymnosperm: a vascular seed plant whose seeds are not enclosed by a fruit 2

3 Angiosperm: a flowering plant that produces seeds within a fruit Ovule: a structure of a seed plant that contains a female gametophyte and that develops into a seed after fertilization Seed: a plant embryo that is enclosed in a protective coat Pollen Grain: the structure that contains the male gametophyte of seed plants Pollination: the transfer of pollen from the male reproductive structures (anthers) to the top of the female reproductive structures (pistil) of a flower in angiosperms or to the ovule in gymnosperms I. Kinds of Seed Plants A. First appeared about 380 Million Years Ago B. 2 Groups C. Gymnosperms D. Angiosperms 4. II. Reproduction in Seed Plants A. Ovule (gametophyte) 3

4 B. Pollen Grain (gametophyte) C. After pollination ovule turns into seed D. Pollination and Fertilization Transfer of pollen grains from male reproductive structure of a plant to the female reproductive structure Fusion of egg and sperm E. Seed Formation After pollination seed contains an Outer cell layers harden to form seed coat Contains nutrients to supply embryo with food F. Seed Dispersal Wind a. Conifers have b. Maples have c. Dandelions and Milkweeds have Animals a. b. seed dispersed when pass though animal undigested III. Gymnosperms A. 4 major groups 4. B. Conifers 4

5 Grow in cool dry regions of the world C. Cycads Short stems Found in Tropics 4. D. Ginkgoes Seeds do not develop in a cone E. Gnetophytes Diverse group of trees, shrubs, and vines Produce pollen and seeds in cones Welwitschia desert plant in SW Africa Section 4: Flowering Plants Monocot: an angiosperm that produces seeds that have only one cotyledon Cotyledon: the embryonic leaf of a seed Dicot: an angiosperm that produces seeds that have two cotyledons Stamen: the male reproductive structure of a flower that produces pollen and consists of an anther at the tip of a filament Anther: the tip of a stamen, which contains the pollen where pollen grains form Pistil: the female reproductive part of a flower that produces seeds and consists of an ovary, style and stigma Fruit: a mature plant ovary, the plant organ in which he seeds are enclosed 5

6 I. Kinds of Angiosperms A. Range in size from tiny herbs to giant trees B. Two Subgroups Monocots a. b. Long narrow leaves c. Parallel veins d. Dicots a. b. Leaves with branching veins c. Flowers whose parts are in multiples of 4 or 5 II. Reproduction in Angiosperms A. Flower Specialized reproductive structure of an angiosperm B. Structure of a Flower Sepals Petals Stamen male reproductive structure; 4. Pistil female reproductive structure; C. Kinds of Flowers a. Contains all 4 parts a. Missing 1 or more parts 6

7 III. Pollination A. Self-fertilization B. Cross-fertilization C. Many angiosperms adapted for pollination by wind or animals IV. Fruits A. Ovary of a pistil B. Develops fro an ovary and contains seeds C. V. Vegetative Reproduction A. Asexual reproduction of a plant B. Tubers potatoes Chapter 24: Seed Plant Structure and Growth Section 1: Plant Tissue Systems Dermal Tissue: the outer covering of a plant Vascular Tissue: the specialized conducting tissue that is found in higher plants and that is made up mostly of xylem and phloem Stoma: opening in a leaf or stem of a plant that enables gas exchange to occur Guard Cells: one of a pair of specialized cells that border a stoma and regulate gas exchange Xylem: the type of tissue in a vascular plant that provides support and conducts water and nutrients from the roots Phloem: the tissue that carries organic and inorganic nutrients in any direction, depending on the plant s needs I. Plant Tissues A. Vascular Plants have 3 Types of Tissues 7

8 a. Outer covering a. Conduction tissue a. All other tissue B. Dermal Tissue System Single layer of flat cells Cuticle a. b. c. Stomata (Stoma) a. Pores that open for gas exchange b. Guard cells surround stoma to open and close C. Vascular Tissue System a. Thick walled cells that conduct water and minerals from roots through stems to leaves b. a. Conduct sugars and nutrients though out plant s body 8

9 Section 2: Roots, Stems and Leaves I. Roots A. B. C. Some store organic nutrients D. Root systems fibrous root system taproot system II. Stems A. Support the leaves B. House vascular system C. Nonwoody stems Flexible usually green D. Woody Stems Not green III. Leaves A. Blade Flat portion attached to stem by stalk called petiole Section 2: Plant Responses Chapter 25: Plant Processes Tropism: the movement of all of part of an organism in response to an external stimulus Phototropism: a plant growth movement that occurs in response to the direction of a source of light 9

10 Thigmotropism: a response of an organism or part o an organism to touch, such as the coiling of a vine around an object Gravitropism: the growth of a plant in a particular direction in response to gravity Photoperiodism: the response of plants to seasonal changes in the relative length of nights and days Dormancy: a state in which seeds, spores, bulbs and other reproductive organs stop growth and development and reduce their metabolism especially respiration Nastic Movements: a type of plant response that is independent of the direction of a stimulus I. Tropisms A. Response where a plant grows toward or away from stimulus B. Phototropism Positive Tropism Heliotropism C. Thigmotropism Tendrils or stems of climbing plants bend when touched D. Gravitropism II. Seasonal Response A. Plants time seasonal responses by sensing changes in night length B. Photoperiodism 3 types a. Short-day plant responds when a day becomes shorter 10

11 b. Long-day plant c. Day-neutral plant 11