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BRYOPHYTES. MOSSES -well adapted to wet, nutrient poor soil. -can tolerate low temperatures -can grow in harsh conditions where other plants can’t grow -are the most abundant plant in the polar regions. .
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BRYOPHYTES • MOSSES -well adapted to wet, nutrient poor soil. -can tolerate low temperatures -can grow in harsh conditions where other plants can’t grow -are the most abundant plant in the polar regions.
-vary in appearance from miniature evergreen trees to small, filimentous plant together form a thread like carpet. -the moss plants we observe in our environment are clumps of gametophytes growing close together. -each moss plant has a thin upright shoot that looks like a stem with tiny leaves – these are not true stems or leaves b/c they do not contain vascular tissue. -When mosses reproduce the produce thin stalks, each containing a capsule – sporophyte stage.
Leaves – only one cell thick – loss water quickly if the surrounding air is dry. • Rhizoids – not true roots – absorb water and nutrients from the soil -water moves from cell to cell through the rhizoids and into the rest of the plant. -anchor the gametophyte to the soil
BRYOPHYTES • Dependence on water: -for fertilization to occur the sperm must swim to the egg – this requires water. -b/c of this dependence on water bryophytes must live in habitats where water is available.
Asexual or Sexual Reproduction • Sexual Reproduction -gametophyte/ sporophyte life cycle Asexual Reproduction -vegatively – a piece of the plant falls off and falls to the soil and begins to grown
HUMAN USES OF MOSSES ★Most mosses can absorb many times their own weight in water and therefore act as a natural sponge. ★In certain environments the dead remains of sphagnum moss accumulates to form thick deposits of peat. -Peat can be cut from the ground and used as a fuel.
-peat is used by gardeners b/c it improves the soils ability to retain water. • -can be added to soil to • __________the pH. Some plants grow well in ______ soil.
LIVERWORTS • -look like flat leaves attached to the ground. • -some species resemble the shape of a liver • -the gametophytes form broad and thin structures that draw up water directly from the surface of the soil. • Found only in soil that is damp yr round. • A mature plant will produce a structure that looks like a tiny green umbrella – these structures produce the sperm and eggs.
HORNWORTS • -only found in soils that are damp year round • -the gametophyte looks very similar to the gametophyte of a liverwort. • The sporophyte looks like a tiny green horn.
Kingdom Plantae PHYLUMs of Nonvascular plans: -Bryophyta ( Moss) -Hepaticophyta (Liverworts) -Anthcerophta (Hornworts).
BREAK • BREATHE, BREATHE, BREATHE.
22-3 SEEDLESS VASCULAR PLANTS • VASCULAR TISSUE -xylem -phloem -move fluids through the plant body, even against the force of gravity. -study the structure of vascular tissue next class when we study roots, stems and leaves. ★spore bearing vascular plant.
FERNS AND THEIR RELATIVES • -CLUB MOSSES, HORSETAILS AND FERNS. • HAVE TRUE ROOTS, LEAVES AND STEMS
ROOTS • Are underground organs that absorb water and minerals. • Vascular tissue is located in the centre of the root.
Leaves • Are the photosynthetic organs that contain one or more bundles of vascular tissue. • The vascular tissue is bundled into veins.
STEMS • Are supporting structures that connect roots and leaves, carrying water and nutrients btw them.
CLUB MOSSES -produced Earth’s first forests -today club mosses are small plants that live in moist woodlands. -some look like miniature pine trees – common name is ground pine.
HORSETAILS Omit.
FERNS • Large leaves are called ____________. • Creeping underground stems are called _________. • Most abundant in _____habitats or seasonly _____habitats.
Life Cycle of Ferns • Vascular plants – have a life cycle in which the diploid sporophyte is the dominant stage • The plant we recognize as a fern is a diploid sporophyte. Assignment 2 – LIFE CYLCLE OF A FERN due at the beginning of next class
BREAK • BREATHE, BREATHE, BREATHE.
22-4 SEED PLANTS • Acorns, pine nuts, dandelion seeds, kernels of corn, seeds can be found everywhere. • Two types of seed plants i. Gymnosperms ii. Angiosperms
Why have seed plants become so successful? • 1. Fertilization does not require water, therefore • 2. Seed plants can live almost anywhere. • 3. Adaptions that allow seed plants to reproduce w/o water include • i. Flowers or cones • Ii. Transfer of sperm by pollination. • Iii. Protection of embroys in seeds.
i. Flowers and Cones -the gametophyte of seed plants grow and mature w/isporophyte structures called cones which are the seed bearing structure of gymnosperms and flowers which are the seed-bearing structures of angiosperms.
ii. Pollen • In seed plants the entire male gametophyte is contained in a structure called a pollen grain. • Sperm produced by this gametophyte do not swim thru water fertilize the eggs, instead the pollengrain is carried to the female reproductive structure by wind, insects or small animals. • The transfer of pollen from the male reproductive structure to the female reproductive structure is called pollination.
iii. Seeds • A seed is the embryo of a plant that is encased in a protective covering and surrounded by a food supply. • An embryo is an organism in its early stages of development – its diploid. The embryo often stops growing while it is contained within the seed; the embryo can remain like this for weeks, months, or even years. • When the embryo does begin to grow it uses nurtients from the stored food supply – grows into a sporophyte.
The seed coat surrounds and protects the embryo and keeps the contents of the seed from drying out. • Seeds can survive long periods of extreme weather conditions – only to grow when the conditions are right • Seeds may also have special tissues or structures that aid in their dispersal to other habitats • Ex. Some seed coats are textured so they stick to the fur or feathers of animals. • Ex. Some seeds are contained in fleshy tissues that are eaten and dispersed by animals.
Gymnosperms -bear their seeds directly on the surface of cones. -incl conifers, cycads, ancient ginkgoes and gnetophytes.
Gymnosperms continued Gnetophytes p566
Cycads p567 – palm like plant that reproduce with large cones. Found in Mexico, the West Indies, Florida, parts of Asia Africa and Australia
Confers p567 -568 -most common gymnosperm – includes pines, spruces, firs, cedars,sequoias, redwoods, junipers and yews. -giant redwoods grow up to 100 meters in hgt. -some pine trees can live for more than 4000 years.
Ecology of Conifers • Conifers can live in a variety of biomes – on mtns, in sandy soil, in cool, moist areas . • Conifer leaves have specific adaptations to dry conditions. • - scientists believe that historically conifers lived in dry cool conditions.
Conifer leaves are long and thin, this shape reduces the surface area from which water can be lost by evaporation; contain a thick waxy coating; the openings that allow for gas exchange are on the bottom of the leaf also reducing water loss.
Most conifers are evergreens – their leaves stay on the tree all year round and are replaced gradually over 2 – 14 years. • Some conifers are not evergreen – such as larches and baldcypresses – they lose their needles every fall.
BREAK • BREATHE, BREATHE, BREATHE.
ANGIOSPERMS(Enclosed Seed) • Are flowering plants, bear their seeds within a layer of tissue that protects the seed. • Develop unique reproductive organs known as flowers. • Incl grasses, flowering trees and shrubs, all wildflowers and cultivated flowers.
Angiosperms continued • Flowers are an evolutionary advantage to plants b/c they attract animals such as bees, moths, hummingbirds, which then transport pollen from flower to flower. • Animal Pollination is more efficient than wind pollination of most gymnosperms.
Flowers contain ovaries which surround and protect the seeds. • After pollination the ovary develops into a fruit, which protects the seed and aids in its dispersal. • By using fruit to attract animals, flowering plants increase the ranges they inhabit, spreading seeds over 100s of kms.
Categorizing Angiosperms • Monocots/Dicots • Woody and Herbaceous Plants • Annuals, Biennials and Perennials. CONTINUE WITH THIS NEXT CLASS FOR NEXT CLASS:
Assignment 2: LIFE CYCLE OF A FERN: Draw, color code and label the life cycle of a fern. Include the following terms: frond, sori, sporangium, sporophyte, spores, gametophyte, anteridium, archegonium, sperm, egg, sporophyte embryo, meiosis, fertilization, mitosis, haploid, n, diploid, 2n. AND….
Assignment 3 • How do seeds differ from spores?
BREAK • BREATHE, BREATHE, BREATHE.