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 minerals

Leaves: photosynthetic organs that contain bundles of vascular tissue

Veins: the vascular tissue is gathered into these structures; made of xylem and phloem

Stems: support structures

Club mosses, Horsetails, and Ferns

Seed Plants Divided into 2 groups: Gymnosperms and

angiosperms

Gymnosperms: bear seeds directly on surface of cones

Conifers: pines and spruces

Angiosperms: also called flowering plants; bear seeds within a layer of tissue that protect the seed

Grasses, flowering trees, and shrubs

Adapted to a reproductive life without the need for water

Transfer 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 parts

Petals: often brightly colored; found just inside sepals

Stamens: the male parts of a flower; composed of anther and filament

Carpels: the female parts of a flower; composed of stigma, style and ovary

Filament

AntherStigma

Style

Ovary

Carpel

PetalSepalOvule

Stamen

 The Structure of a Flower

Stamen: produces haploid male gametophytes (pollen)

Carpel: pollen lands on sticky stigma

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