Chapter 18

1. Chapter 18 By: Cody Crawford

2. 18-1 ProtistWhat is a Protist? • All protist are eukaryotes-they contain a nucleus & have organelles • All protists vary in size • Most protists need O2 (aerobic)- others don’t (anaerobic) • Some are autotrophs; other are heterotrophs • Some are sexual; others are asexual

4. Living Protists • Autotrophic protists • Ex)algae are photosynthetic autotrophs • 30,000 species of algae- fresh/marine • 30-40% of all photosynthesis on earth is performed by these protists

5. Single celled algae include • Euglenophyta • Pyrophyta • Chrysophyta

6. Multicellular algae • Chlorophyta • Rhodophyta • Phaeophyta

7. Heterotrophic protists • EX)commonly known as protozoans-can be viewed with a light microscope

8. Reproduction of protists • Euglenophyta reproduce asexually • Gametophytes reproduce sexually

9. 18-2 Fungi • Fungi- heterotrophic eukaryotes that have cell walls • Most fungi are multicellular • The cell walls do not contain cellulose but instead contain chitin

10. Basic structures of a fungi • Threadlike filament called a hypha-grows down into whatever the fungus is feeding on- forms a mass called the mycelium (secretes enzymes that breaks down compounds) when the conditions are right, parts of the mycelium may be organized into the fruiting body of what we call a mushroom

11. Four Phyla of Fungi • Zygomycota • Ascomycota • Basidiomycota • Deuteromycota

12. What They Are • Zygomycetes-often called bread mold EX)black mold • Ascomycetes-often called sac fungi 30,000 species of mildews,molds,& yeast this is the largest phylum of the kingdom fungi • Basidiomycetes-includes the mushrooms EX)puffballs • Deuteromycetes-sometimes called “imperfect fungi” EX) penicillium is good; athletes foot&jock itch –bad

13. More of what they are • Lichens- greenish scalelike patches on tree trunk trunks • They are a symbiotic partnership between a fungus and a photosynthetic algae

14. Reproduction of fungi • Both sexually and asexually

15. 18-3 muticellular plants • Kingdom plantae • All plants are multicellular, photosynthetic eukaryotes who cells are enclosed & supported by a cell wall made up of cellulose • The majority of plants reproduce sexually but not all

16. Bryophytes • Include mosses,liverworts, hornworts, and peat mosses • Survive in wet climates • Grow not more than a few cm tall • Peat mosses grows almost totally under H20

17. Tracheophytes • Contain vascular tissues that transport H20 and nutrients • Grow much larger & have a wider range of habitats than the bryophytes • Other examples gymnosperms & angiosperm • Ferns is a simple tracheophyte

18. Gymnosperms • 1st seed bearing tracheophytes • EX)cycads,ginkgoes,& conifers • They carry their seeds exposed to air in a cone shaped structure • Seeds and reproductive structure that include a developing plant and a food reserve are enclosed in a resistant outer covering • Most common is the conifers which are known for their cones & needle like leaves -Cones produce & carry seeds -Often called evergreens

19. Angiosperms • These are food sources for humans & other animals • Reproduce & mature quicker than gymnosperms • Divided into two groups- monocots & dicots • Cotyledons-structure in seeds that contain food for the developing plant • Monocots-rice,wheat,corn,lilies,orchids,tulips,& palms- containe one cotyledon • Dicots- tomatoes,roses,maples,sunflowers-contain two cotyledons

20. Structures of the Plant • Roots-anchor plants in soil; absorb H20 & nutrients • Leaves-provide the surface area over which the plant can capture sunlight for photosynthesis -Broader & flatter the leaf- the more sunlight it captures -this also allows for more H20 lost to evaporation -to resolve this issue, plants have a waxy H20 proof covering on their leaves called a cuticle • Cuticles are dotted with tiny openings called stomata (which allow for gas exchange)

21. Vascular tissues • Xylem-carries H20 & dissolved in organic nutrients from the roots to the branches & leaves; cell walls are thick with cellulose; major sources of strength in woody plants • Phloem- carries the products of photosynthesis from one part of a plant to another; the transport of these materials may be upward or downward

22. Stems • Stems- hold leaves up to the sun and position leaf surfaces to capture as much light as possible • Also conduct H20, nutrients, products of photosynthesis, & other materials through the plant by means of their vascular tissues

23. How do Plants Reproduce? • All plant life cycles involve alternation of generations between sporophyte and gametophyte • In mosses, the gametophyte is the longest part of the cycle • In flowering plants, the sporophyte part of the cycle is much longer

24. Mosses • Mosses- gametophyte generation consists of male and female structure called sperm and eggs • The sperm must fertilize the egg to produce a zygote • This zygote grows into the sporophyte -a slender stalk with a spore capsule on the end -inside this capsule, meiosis produces spores -the spores are dispersed & produces gametophyte plants

25. Pollen&Seeds • Seed plants are members of the dominant sporopyte generation • The gametophytes have been reduced to small clusters of a few cells that grow inside structures called: cones in gymnosperms and flowers in angiosperm

26. Pollen&Seeds (con’t) • The entire male gametophyte is contained in a tiny structure called pollen • A pollen grain produces sperm & is carried by the wind to eggs • Insects, beetles,birds,& bats also carry pollen to eggs • Once pollen lands on the female egg part, a long tube containing the sperm begins to grow down inside the flower until it reaches the eggs • After fertilization, the egg grows into an embryo • The embryo becomes dormant inside a seed • A seed provides protection and food; waits for germination