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Plant Kingdom

Plants are multicellular,

Primarily terrestrial eukaryotes

Autotrophic by photosynthesis

Approximately 265,000 different types of

plants exist today. Plants began the transitionto land about 425 million years ago.

Plants play a critical role as producers in the

world's food webs; using photosynthesis toproduce organic biomass and releasingoxygen as an end-product.

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Plant Kingdom

Terrestrial plants carry on gas exchangethrough pores (stomata) on the surface ofleaves.

Oxygen and water vapor leave thru stomata,and carbon dioxide enters through thestomata. (note: stoma (singular))

The leaves are covered with a waxy cuticle toprevent desiccation.

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Plant Kingdom

Plant chloroplasts contain chlorophyll a,chlorophyll b, and a variety of yellow andorange carotenoids.

Plant cell walls are composed of cellulose.

Plants store carbohydrate as starch.

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Plant reproduction Nearly all plants reproduce sexually, though many

also are capable of asexual modes of reproduction.

Alternation of generations occurs in the life cycle ofplants, with a haploid, gamete-producing gametophyte

stage alternating with a diploid, spore-producingsporophyte stage.

Bryophytes (true mosses) have a large, obvious

gametophyte stage, but in other plants the sporophyte stage is larger

and the gametophyte stage has been reduced.

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Alternation of generations

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Plant Evolution - marked by four major

adaptations:

(1) about 400 million years ago - the featureof a protected embryo; also spore productionas a means of reproduction;

(2) the evolution of vascular tissue;

(3) the origin of seed producing plants about360 million years ago; and

(4) the evolution of flowering plants about 130million years ago.

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Plant

Evolution

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Seedless vasculare.g. ferns

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Gymnospermsseed cones

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Angiospermsseed flowering

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Plants - Basic Vocabulary

vascular tissue - plant tissues that consist of cells that transport waterand nutrients throughout the plant body. The two major types are xylemand phloem. xylem - vascular tissue that carries water and minerals from the roots to the

rest of the plant. phloem - vascular tissue that carries sugar and organic nutrients (sap)

throughout the plant.

gametangium - the gametophyte stage of mosses consisting of a maleantheridium (sperm) and a female archegonium (egg)

gametophyte - multicellular, haploid stage of the life cycle that produceshaploid gametes that fuse to form the diploid sporophyte sporophyte - multicellular, diploid stage of the life cycle that through

meiosis produces haploid gametes that become the gametophyte

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Vascular tissue

xylem - vascular tissue that carries water andminerals from the roots to the rest of the plant.

phloem - vascular tissue that carries sugar andorganic nutrients (sap) throughout the plant.

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Plant Kingdom: The Classification of Plants (Four major groups exist):

Bryophytes(mosses) andRelatives

Pteridophyta(Ferns) andRelatives

Gymnospermsand Relatives

Angiosperms andRelatives

Examples Mosses,liverworts,hornworts

Ferns,Psilotum(whisk fern),Lycopodium,Equisetum(horsetails)

Conifers,Gingko, cycads

Flowering plants,grasses,hardwoods

Vascular tissue(xylem and

phloem)

Nonvascular Vascular Vascular Vascular

Sporophyte/Gametophyte

Gametophyte(N) dominant

Sporophytedominant,small separateGametophyte

Sporophytedominant

Sporophytedominant

Reproduction(spores orseeds)

Spores Spores Seeds Seeds

Reproduction(Fertilization)

Water Water Wind(Pollination)

Wind/ animals(Flowers)

Reproduction(Seed/sporedispersal)

Water/ WindSpores

Water/ WindSpores

WindSeeds

Wind/animals(Fruits)Seeds

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Reduction in size of the gametophyte

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Nonvascular PlantsMosses and Relatives -

bryophytes

No true roots (rhizoids), stems, or leaves

Gametophyte stage dominant, no vascular tissue,spores as a means of reproduction

Phylum Bryophyta - (true mosses)

(10,000 species)

Phylum Hepatophyta (liverworts)(6500 species)

Phylum Anthocerophyta (hornworts)

(100 species)

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1. Bryophytes and their relatives Phylum Bryophyta (mosses) - lack vascular tissue but have

certain adaptations that made a terrestrial existence possibleincluding having a waxy cuticle, and female gametes thatdevelop and are fertilized within a protective gametangia. Themale gametangium is the antheridium and the femalegametangium is the archegonium. The egg is fertilized withinthe archegonium and the sporophyte stage grows out of the

body of the gametophyte stage. Because mosses lack vascular tissue they must absorb water

by diffusion and capillary action which limits them to shady,moist habitats and a relatively small body size.

1. antheridium

2. archegonium 3. sporophyte

4. gametophyte

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Moss

life cycle

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Bryophytes and their relatives, contd.

* Phylum Hepatophyta (liverworts) -diminutive plants with lobed bodies ("lobedherbs"), liverworts have a life cycle similar to

mosses. They can also reproduce asexuallyby gemmae (groups of cells) which aredispersed when raindrops fall into theirprotective cups.

* Phylum Antherocerophyta (hornworts) -resemble liverworts but have horn-shapedsporophyte stage

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Vascular Plants Seedless

sporophyte stage dominant; small gametophytepresent; vascular tissue present; spores as ameans of reproduction

Phylum Psilophyta (whiskferns)

(13 species) Phylum Lycophyta (club mosses)

(1,000 species)

Phylum Sphenophyta (horsetails)

(15 species) Phylum Pterophyta (ferns)

(12,000 species)

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2. Ferns and their relatives:

Phylum Psilophyta (whiskferns) - Psilotum,lacks true roots and leaves, have rhizomeswhich are underground stems covered with

rhizoid hairs. The body plan of the whiskfernsprobably is similar to the earliest vascularplants.

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Ferns and their relatives, contd.

Phylum Lycophyta (lycopods, club mosses,ground pines) - Lycopodium and Sellaginella,the sporangia of Lycopodium are borne on

sporophylls, leaves specialized forreproduction. Gametophyte stage isinconspicuous and develops underground.Heterosporous, the megaspores develop into

female gametophytes bearing archegoniaand the microspores develop into malegametophytes bearing antheridia.

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Ferns and their relatives, contd.

Phylum Sphenophyta (horsetails):Equisetum, conspicuous sporophyte, silica inthe epidermal cells give these plants a glassy

texture. Equisetum was also formerly called"scouring rush" because the glassy texturemade them useful for scrubbing pots andpans. Gametophyte stage is small butphotosynthetic and free-living.

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Ferns and their relatives, contd.

Phylum Pterophyta (ferns): large sporophyte stage,ferns are widely distributed in the tropics andrelatively common in temperate regions. Some ofthe leaves (fronds) of ferns are specialized

sporophylls with clusters of spores called sori on theunderside of the frond. The airborne spores arecatapulted from the sorus.

frond leaves of ferns

sorus

on underside of leaves/ hold spores rhizome branching underground stem w/ rootlike

hairs

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Fern life cycle

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Vascular Plants - Seed Producers

sporophyte stage dominant; vascular tissue, seeds as ameans of reproduction

3. Gymnosperms

Division Coniferophyta (conifers)(550 species)

Division Cycadophyta (cycads)

(100 species)

Division Ginkgophyta (ginkgo)

(1 species) Division Gnetophyta (gnetae)

(70 species)

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3. Gymnosperms and their relatives:

Phylum Coniferophyta (pines, spruce, firs, larches,

cedars, cypresses, redwoods): produce a cone which supports and protects the

seed.

Most conifers are evergreen and their needle-

shaped leaves adapt them to dry habitats. Important source of most of our lumber and pulp

paper.

The bristlecone pine is one of the oldest organisms

(4600 years old), while the redwoods are the largestorganisms alive (the "General Sherman" tree has atrunk circumference of 26 m.

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Phylum Coniferophyta, contd.

In the life cycle of the pine, the sporophytegeneration would be represented by the pinetree itself, while the gametophyte generation

has been reduced to female (ovulate) andmale (pistillate) cones. These plantsproduce true seeds which consist of adeveloping embryo, a nutrient supply, and a

protective seed coat. Conifers aremonoecious since trees produce both pollenand seed cones.

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life cycle of the pine

Phylum Coniferophyta

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Pollen grains

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4. Angiosperms

sporophyte dominant, vasculat plants, seeds,fruits and flowers

Phylum Anthophyta (flowering plants)

(240,000 species)

The angiosperms are extremely importantproviding all of our fruits and vegetables, and

providing medicines, fiber, perfumes, anddecorations.

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4. Angiosperms and their relatives

Angiosperms (flowering plants) - thedominant form of plant life on earth at thepresent time; 240,000 species.

monocots Monocotyledons

dicots Dicotyledons

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monocots Monocotyledons

Consists of monocots (lilies,orchids, yuccas, palms, pineapples,grasses, and cereal grains) which

have flower parts in threes ormultiples of three (3); and

one cotyledon (seed leaf) in theirseeds

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Monocot flower, a daylily

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dicots Dicotyledons

dicots (oak, hickory, asters, roses, maples,strawberries, cactuses, beans) which have flowerparts in four or fives, or multiples of four (4) or five(5), and

two cotyledons (seed leaf) in their seeds

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Dicot flower, an azalea

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Angiosperm characteristics

Have well-developed and efficient vascular tissueincluding xylem (tracheids and vessels) and phloem(sieve tubes and companion cells).

Four major flower parts may be present: the calyxconsisting of sepals that protect the flower; thecorolla consisting of petals to attract pollinators; thestamens (male pollen-producing structure consisting

of and anther and filament); and the carpel (pistil)(female egg-producing structures consisting of thestigma, style, and ovary).

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General Flower Structure - Angiosperms

pistil

male pollen-producingstructure

female egg-producingstructures

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Flower diversitymonocots and dicots

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Angiosperm Vocabulary

ovule - holds the megasporangium and femalegametophyte which produces an egg; the ovule laterbecomes the seed

ovary - the enlarged base of the pistil, which forms

the fruit fruit - a ripened, thickened ovary of a flower, which

protects the seeds and assists their dispersal

pollination - transfer of pollen from microsporangium

to female gametophyte fertilization - fusion of sperm nucleus with egg

nucleus

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AngiospermFlowering plant life cycle

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Four Trends in Angiosperm Evolution

1. Number of floral parts has been reduced

2. Floral parts have become fused

3. Symmetry has changed from radial to bilateral

4. Ovary has dropped to a position below the petalsand sepals (inferior) where the flowers are betterprotected

* Flowering plants and land animals have co-

evolved to develop many different types ofrelationships related to pollination and reproduction.

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Plant uses and benefits

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Plant uses and benefits

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Plant uses and benefits

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Plant uses and benefits

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Plant uses and benefits

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Plant uses and benefits

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Plant uses and benefits