Ms. Moore 8/30/12

 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 is unique to a plant cell?

 2 alternating phases Sporophyte: spore-producing plant; occurs in diploid (2N) phase Gametophyte: gamete-producing plant; occurs in haploid (N) phase

 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

 Include: Gnetophytes Cycads Ginkgoes Conifers

 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