2 Why are they relevant? Photosynthesis provides Oxygen Plants are the basis of all food chainsClothing, medicine, textiles, etc.Interlocking roots prevent erosion
3 Where did they come from? Fossil record is sketchy (no hard parts to fossilize)Most scientists believe they came from green algae (protists) and moved to land to get closer to the sun…
4 Plant Characteristics All are Multicellular EukaryotesAll contain chloroplastsMost are non-motile
5 Groups of plants: Seedless Bryophytes: Mosses, liverworts and hornworts.One cell thick, very primitive, must remain wet.No veins to carry food and water, they use osmosis insteadNeed water for sperm to swim to egg in reproduction (no seeds)
6 Groups of Seedless Plants Continued… FernsLeaf is called a frondStill no seeds, sperm swim to eggHave vascular tissue, so they can grow tallerTypes of vascular tissue:Xylem carries water up from rootsPhloem carries sugar down from leaves
7 Groups of plants continued… SEED plants Vascular SEED Plants:Gymnosperms: “naked seed” evergreens like pine and spruce. Seed does not have any protection and develops on a cone.Angiosperms: “seed in a vessel” or a fruit. Flowering plants that use fruits to protect the seeds
8 Angiosperms Annual v. Perennial Anything that has seeds is a FRUIT!! Peppers? YES!Pumpkins? YES!Tomatoes? YES!Corn? YES!
9 Two divisions of angiosperms: Monocots: have ONE seed leaf (Cotyledon) and leaves have PARALLEL veins.Example: grass or palm treesDicots: have TWO seed leaves and leaves have branched veins.Example: oak tree (deciduous) or rose
10 Plant Organs: Roots, stems, leaves and flowers Roots: Collect waterTap roots or fibrousRoot hairs increase surface area and absorption of roots
11 Plant OrgansStems: Transport food down the stem in the phloem and water up the stem from the roots to the leaves in the xylem.
12 Plant OrgansLeaves: Covered with waxy cuticle, filled with chloroplasts, get held broad to the sun so they can easily photosynthesize, have veins of xylem and phloem.Contain stomata (a pore) surrounded by 2 guard cells which let CO2 in depending on whether or not the plant has enough water (turgidity)Wilted = closed full = turgid and open
28 Question 1 A. cellulose B. proteins C. glucose D. chlorophyll Most plants produce their own food in the form of _______.A. celluloseB. proteinsC. glucoseD. chlorophyllThe answer is C.
29 Question 2 Answer Why are most plant roots not covered in a cuticle? The waxy cuticle would prevent the plant’s roots from absorbing water and nutrients.
30 Question 3 A. absorbing water and nutrients Which of the following is NOT a function of most plant roots?A. absorbing water and nutrientsB. conducting photosynthesisC. store starchD. anchoring the plantThe answer is B.