Presentation on theme: "Ms. Moore 8/30/12. Plants are: Multicellular Eukaryotes Photosynthesis using chlorophyll Most are autotrophs (some can be parasites or saprobes that."— Presentation transcript:
Plants are: Multicellular Eukaryotes Photosynthesis using chlorophyll Most are autotrophs (some can be parasites or saprobes that live on decaying material) Fossil evidence: 470 million years ago
What do plants need to survive? Sunlight Water and Minerals Gas Exchange (O 2 and CO 2 ) Movement of Water and Nutrients Evolved from an organism much like the multicellular green algae living today.
Botanists group based on 3 features: Water-conducting tissues Seeds Flowers Botanists have 4 groups: Flowering plants: 235,000 species Mosses and relatives: 15,600 species Ferns and their relatives: 11,000 species Cone-bearing plants: 760 species
Bryophytes: non-vascular plants ex.: moss, liverworts, and hornworts Life cycles depend on water for reproduction because they lack vascular tissue (use osmosis)
Mosses Abundant in areas with water: swamps and bogs, near streams, and in rain forests Rhizoids: long, thin cells that anchor them in the ground and absorb water (no roots) Liverworts Look like little green umbrellas Can reproduce asexually with gemmae (smal multicellular reproductive structures; can form a cup) Hornworts Much like liverworts, except their sporophyte looks like a tiny green horn.
Gametophyte is the dominant stage. Dependence on water for fertilization to occur—sperm of bryophyte must swim to egg. Protonema: mass of tangled green filaments that forms rhizoids; from germinated sporophyte Antheridia: produces sperm Archegonia: produces egg
Vascular Tissue: transport system for water and nutrients Have true roots, leaves, and stems 2 types vascular tissue: Xylem: carries water upward from roots Phloem: transports nutrients and carbs produced from photosynthesis Examples: ferns, club moss, horsetails
Have characteristics of vascular plants: Roots Rhizomes Leaves Fronds Life Cycle: Diploid sporophyte is dominant stage. Develop spores on underside of fronds in tiny containers: sporangia or groups called sori.
2 groups: Gymnosperms: bear seeds directly on the surfaces of cones Angiosperms: flowering plants; bear their seeds within a layer of tissue that protects the seed Pollination transfer of pollen(male gametophyte) from male to female reproductive structure
Seed: embryo of a plant that is encased in a protective covering and surrounded by a food supply Embryo: organism in early stage of development Seed Coat: surrounds and protects embryo
Characteristics: Develop flowers: unique reproductive organs; contain ovaries which protect seeds Fruit: wall of tissue surrounding the seed (increases range of habitat)
Monocots: Single cotyledon Parallel veins Floral: multiples of 3 Vascular bundles throughout stem Fibrous roots Dicots: Two cotyledons Branched veins Floral: multiples of 4/5 Vascular bundles in ring Taproot (carrot)
Annuals: complete one life cycle within one growing season Ex: marigolds, petunias, pansies, wheat, cucumbers Biennials: 2 nd year produce flowers and seeds then die! Ex: evening primrose, parsley, celery, foxglove Perennials: live for more than 2 years Herbacious: peonies, asparagus, grasses Woody: palm trees, maple trees, honeysuckle