PLANTS-A brief introduction of chapters 22 thru 25

What is a plant?

Multicellular eukaryotes Cell walls made of celluloseCarry out photosynthesis using

chlorophyll a & bMost are autotrophs

Plant Life Cycle

All plants have a life cycle with alternation of generations

Alternate between haploid and diploid phases

Gametophyte and sporophyte

Plant Survival

SunlightWater and mineralsGas exchange

Photosynthesis and cellular respiration

Water movement and nutrients

Evolution and classification of Plants

Floweringplants

Cone-bearingplants

Ferns andtheir relatives

Mosses andtheir relatives

Green algaeancestor

Flowers; SeedsEnclosed in Fruit

Seeds

Water-Conducting(Vascular) Tissue

* The plant kingdom is divided up into 4 groups based on water conducting tissues, seeds, and flowers.

Bryophytes (Non-vascular plants)

Do not contain vascular tissue (specialized tissue that conducts water and nutrients)

Depend on water for reproduction through osmosis

Relatively small Live in areas where there is rainfall or dew

Examples of Bryophytes

Mosses Liverworts Hornworts

Seedless Vascular Plants

2 types of tissue• Xylem: carries water upward

• Phloem: transports solutions of nutrients and carbohydrates

• Can move fluids through the plant against force of gravity

Seedless Vascular Plants cont.…

Basic structuresRoots: underground organ that absorb water

and mineralsLeaves: photosynthetic organs that contain

bundles of vascular tissueVeins: the vascular tissue is gathered into

these structures; made of xylem and phloemStems: support structures

Club mosses, Horsetails, and Ferns

Seed Plants Divided into 2 groups: Gymnosperms and

angiosperms Gymnosperms: bear seeds directly on

surface of conesConifers: pines and spruces

Angiosperms: also called flowering plants; bear seeds within a layer of tissue that protect the seedGrasses, flowering trees, and shrubsAdapted to a reproductive life without

the need for waterTransfer sperm by pollination and the

protection of embryos in seeds

Angiosperms

Develop unique reproductive organs known as flowers

Flowers contain ovaries, which surround and protect the seeds

Any guess what an ovary is commonly called?

Angiosperms cont.

Fruit: a wall of tissue surrounding the seed; developed from a mature ovary

Digestion of fruit leads to great success of these plants

2 types of angiosperms; Monocot and Dicot

Monocots Dicots

Seeds

Leaves

Flowers

Stems

Roots

Single cotyledon

Parallel veins

Floral parts often in multiples of 3Vascularbundlesscattered throughout stem

Fibrous roots

Two cotyledons

Branched veins

Floral parts often in multiplesof 4 or 5 Vascular bundles arranged in a ring

Taproot

Comparison ofMonocots and Dicots

Structure of a FlowerA flower is a reproductive organ

that are composed of 4 kinds of specialized leavesSepal: outermost circle of floral partsPetals: often brightly colored; found

just inside sepalsStamens: the male parts of a flower;

composed of anther and filamentCarpels: the female parts of a flower;

composed of stigma, style and ovary

FilamentAnther

StigmaStyle

Ovary

Carpel

PetalSepalOvule

Stamen

 The Structure of a FlowerStamen: produces haploid male gametophytes (pollen)

Carpel: pollen lands on sticky stigma

• Most gymnosperm pollinations takes place via wind, and most angiosperms via animals