Ch 22- Plant Diversity What is a plant? Multicellular eukaryotes, have cell walls made of cellulose Carry out photosynthesis using pigments-chlorophyll a and b Welcome to Discovery Education Player Plant Life Cycle Sporophyte- diploid phase produces spores Gametophyte- haploid phase produces gametes What do plants need to survive? Sunlight, water and minerals, gas exchange, and transport of water and nutrients

First plants evolved from organism similar to modern multicellular green algae 4 groups in plant kingdom based on water-conducting tissues, seeds and flowers Mosses and their relatives Ferns and their relatives Cone-bearing plants Flowering plants

Sec 2- Bryophytes Bryophytes- nonvascular plant Depend on water for reproduction Mosses What adaptations of bryophytes enable them to live on land? Can draw up water by osmosis a few cm above ground Three main groups of bryophytes Mosses, liverworts, and hornworts

Life cycle of bryophytes 3 phyla of non-vascular called Bryophytes Mosses belong to Phylum Bryophyta Others include liverworts and hornworts Characteristics include Usually grow on land near streams and rivers Most primitive type of plant and abundant in polar regions Closely related to algae and most terrestrial Need water to reproduce sexually Contain rhizoids-false roots-root like structure that anchors moss and absorbs nutrients Life cycle of bryophytes Gametophyte is dominant stage Antheridia- male reproductive structure Archegonia- female reproductive structure

Sec 3- Seedless Vascular Plants Vascular tissue- type of tissue that transports water and dissolved substances from roots to leaves Types include xylem and phloem Xylem transports water made up of tracheids- hollow cells with thick cell walls that resist pressure Phloem transports organic compounds Can move fluids against gravity Seedless vascular plants- club mosses, horsetails, and ferns Ferns have underground stems called rhizomes and fronds which are large leaves What are the characteristics of three phyla of seedless vascular plants? Roots, leaves, veins, stems Roots- underground organs that absorb water and minerals Leaves- photosynthetic organs, contain one or more bundles of vascular tissue Veins- vascular tissue in leaves made of xylem and phloem Stems- supporting structures, connect roots and leaves, carry water and nutrients

Life Cycle of Ferns Diploid sporophyte is dominant stage in ferns and other vascular plants Sporangia- structure in ferns that contains spores, diploid Sori- cluster of sporangia on underside of a fern frond

Sec 4- Seed Plants Gymnosperms- seed plants that bear seeds directly on surface of cones Gymnosperm means “naked seed” Conifers such as pines and spruces, cycads, ancient ginkgoes Angiosperms- flowering plants that bear their seeds within layer of tissue that protects seed What adaptations allow seed plants to reproduce without standing water? Flowers or cones- allow transfer of sperm by pollination and protection of embryos in seeds

Cones- seed bearing structure Flowers- seed bearing structure of angiosperm Pollen grain- male gametophyte in seed plants Pollination- transfer of pollen from male reproductive structure to female reproductive structure Seed- embryo of living plant that is encased in protective covering Embryo- organism in its early stage of development Seed coat- structure that surrounds and protects a plant embryo and keeps it from drying out What are the four groups of gymnosperms? Gnetophytes, cycads, ginkgoes, and conifers All reproduce with seeds Conifers- most common Includes pines, cedars, spruces, redwoods, sequoias, junipers

Sec 5- Angiosperms Angiosperms- members of phylum Anthophyta, originated on land What are the characteristics of angiosperms? Flowers- reproductive organs Flowers contain ovaries- surround and protect the seeds Fruit- wall of tissue surrounding the seed

Diversity of Angiosperms What are monocots and dicots? Named for # of seed leaves, or cotyledon- first leaf or first pair of leaves produced by embryo of seed plant Monocots- single cotyledon, parallel veins, flowers in multiples of 3’s, vascular bundles scattered throughout stem, fibrous roots Corn, wheat, lilies Dicots- two cotyledon, branched veins, flowers in multiples of 4 or 5, vascular bundles in ring, taproot Roses, tomatoes, oaks

Woody plants- thick cell walls Herbaceous- smooth and nonwoody stems Trees, shrubs, vines Herbaceous- smooth and nonwoody stems Dandelions, sunflowers What are the three categories of plant life spans? Annuals- flowering plants that complete a life cycle within one growing season Wheat Biennials- flowering plants that complete life cycle in 2 yrs Celery Perennials- flowering plants that live for more than 2 yrs Asparagus, palm and maple trees