PLANTS-A brief introduction of chapters 22 thru 25

1. PLANTS-A brief introduction of chapters 22 thru 25

2. What is a plant? • Multicellular eukaryotes • Cell walls made of cellulose • Carry out photosynthesis using chlorophyll a & b • Most are autotrophs

3. Plant Life Cycle • All plants have a life cycle with alternation of generations • Alternate between haploid and diploid phases • Gametophyte and sporophyte

4. Plant Survival • Sunlight • Water and minerals • Gas exchange • Photosynthesis and cellular respiration • Water movement and nutrients

5. Floweringplants Cone-bearingplants Ferns andtheir relatives Flowers; SeedsEnclosed in Fruit Mosses andtheir relatives Seeds Water-Conducting(Vascular) Tissue Green algaeancestor Evolution and classification of Plants * The plant kingdom is divided up into 4 groups based on water conducting tissues, seeds, and flowers.

6. 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

7. Examples of Bryophytes • Mosses • Liverworts • Hornworts

8. 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

9. 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

10. 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

11. 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?

12. 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

13. Single cotyledon Two cotyledons Parallel veins Branched veins Floral parts often in multiples of 3 Floral parts often in multiplesof 4 or 5 Vascularbundlesscattered throughout stem Vascularbundlesarranged ina ring Fibrous roots Taproot Comparison ofMonocots and Dicots Monocots Dicots Seeds Leaves Flowers Stems Roots

14. 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

15. Stamen Carpel Stigma Anther Style Filament Ovary Petal Ovule Sepal  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