Presentation on theme: "PLANTS-A brief introduction of chapters 22 thru 25."— Presentation transcript:
PLANTS-A brief introduction of chapters 22 thru 25
What is a plant? Multicellular eukaryotes Cell walls made of cellulose Carry out photosynthesis using chlorophyll a & b Most are autotrophs
Plant Life Cycle All plants have a life cycle with alternation of generations Alternate between haploid and diploid phases Gametophyte and sporophyte
Plant Survival Sunlight Water and minerals Gas exchange Photosynthesis and cellular respiration Water movement and nutrients
Evolution and classification of Plants Flowering plants Cone-bearing plants Ferns and their relatives Mosses and their relatives Green algae ancestor Flowers; Seeds Enclosed in Fruit Seeds Water-Conducting (Vascular) Tissue * The plant kingdom is divided up into 4 groups based on water conducting tissues, seeds, and flowers.
Bryophytes (Non-vascular plants) Do not contain vascular tissue (specialized tissue that conducts water and nutrients) Depend on water for reproduction through osmosis Relatively small Live in areas where there is rainfall or dew
Examples of Bryophytes Mosses Liverworts Hornworts
Seedless Vascular Plants 2 types of tissue Xylem: carries water upward Phloem: transports solutions of nutrients and carbohydrates Can move fluids through the plant against force of gravity
Seedless Vascular Plants cont.… Basic structures Roots: underground organ that absorb water and minerals Leaves: photosynthetic organs that contain bundles of vascular tissue Veins: the vascular tissue is gathered into these structures; made of xylem and phloem Stems: support structures Club mosses, Horsetails, and Ferns
Seed Plants Divided into 2 groups: Gymnosperms and angiosperms Gymnosperms: bear seeds directly on surface of cones Conifers: pines and spruces Angiosperms: also called flowering plants; bear seeds within a layer of tissue that protect the seed Grasses, flowering trees, and shrubs Adapted to a reproductive life without the need for water Transfer sperm by pollination and the protection of embryos in seeds
Angiosperms Develop unique reproductive organs known as flowers Flowers contain ovaries, which surround and protect the seeds Any guess what an ovary is commonly called?
Angiosperms cont. Fruit: a wall of tissue surrounding the seed; developed from a mature ovary Digestion of fruit leads to great success of these plants 2 types of angiosperms; Monocot and Dicot
MonocotsDicots Seeds Leaves Flowers Stems Roots Single cotyledon Parallel veins Floral parts often in multiples of 3 Vascular bundles scattered throughout stem Fibrous roots Two cotyledons Branched veins Floral parts often in multiples of 4 or 5 Vascular bundles arranged in a ring Taproot Comparison of Monocots and Dicots
Structure of a Flower A flower is a reproductive organ that are composed of 4 kinds of specialized leaves Sepal: outermost circle of floral parts Petals: often brightly colored; found just inside sepals Stamens: the male parts of a flower; composed of anther and filament Carpels: the female parts of a flower; composed of stigma, style and ovary
Filament Anther Stigma Style Ovary Carpel Petal Sepal Ovule Stamen The Structure of a Flower Stamen: produces haploid male gametophytes (pollen) Carpel: pollen lands on sticky stigma Most gymnosperm pollinations takes place via wind, and most angiosperms via animals