THE PLANT KINGDOMTHE PLANT KINGDOM

All Plants Evolved from All Plants Evolved from Common Ancestor: Ancient Common Ancestor: Ancient

Green AlgaeGreen Algae Cell walls made of celluloseCell walls made of cellulose Store excess carbohydrates as starchStore excess carbohydrates as starch Form a cell plate during cytokinesisForm a cell plate during cytokinesis Have same photosynthetic pigments:Have same photosynthetic pigments:

Chlorophyll a and bChlorophyll a and b Carotenoid – carotene and xanthophyll Carotenoid – carotene and xanthophyll

Adaptations to life on Adaptations to life on land:land:

Cuticle Cuticle Waxy layer on aerial portion that prevents Waxy layer on aerial portion that prevents

dessicationdessication Thickness depends on how dry the Thickness depends on how dry the

environment isenvironment is

Adaptations to life on Adaptations to life on land:land:

CuticleCuticle Stomata: Stomata:

Pores on the surface of leaves and stemsPores on the surface of leaves and stems

Allows for gas exchangeAllows for gas exchange

Adaptations to life on Adaptations to life on land:land:

CuticleCuticle StomataStomata GametangiaGametangia

Multicellular sex organsMulticellular sex organs Covered by a layer of sterile cells – Covered by a layer of sterile cells –

protectionprotection Embryo develops inside gametangiaEmbryo develops inside gametangia

Plant Life CyclePlant Life Cycle

Alternation of Alternation of generationsgenerations GametophyteGametophyte

Multicellular haploid Multicellular haploid stage stage

Produces gametesProduces gametes

SporophyteSporophyte Multicellular diploid Multicellular diploid

stagestage Produces sporesProduces spores

Gametophyte generationGametophyte generation

Gives rise to haploid Gives rise to haploid gametes by mitosisgametes by mitosis

Sperm cells form in antheridiaSperm cells form in antheridia

Egg cells form in archegoniaEgg cells form in archegonia

Once sperm cell fertilizes an egg cell, a zygote Once sperm cell fertilizes an egg cell, a zygote is formedis formed

Sporophyte generationSporophyte generation

Begins with diploid zygoteBegins with diploid zygote

Zygote divides by mitosis and develops into Zygote divides by mitosis and develops into embryo embryo

Grows into mature sporophyte plantGrows into mature sporophyte plant

Specialized cells called Specialized cells called sporogenous cells sporogenous cells divide by meiosisdivide by meiosis into haploid spores into haploid spores

Four Main Groups of Four Main Groups of Plants Plants

BryophytesBryophytes

Seedless Seedless vascular vascular plantsplants

GymnospermsGymnosperms

AngiospermsAngiosperms

BryophytesBryophytes

Nonvascular plants Nonvascular plants Rely on diffusion and osmosis Rely on diffusion and osmosis Restricted in sizeRestricted in size Generally require moist environmentGenerally require moist environment MOSSES, LIVERWORTS, MOSSES, LIVERWORTS,

HORNWORTSHORNWORTS

Moss Life CycleMoss Life Cycle

Vascular PlantsVascular Plants

Ferns, Gymnosperms, AngiospermsFerns, Gymnosperms, Angiosperms

Contain xylem and phloemContain xylem and phloem

Cell walls contain ligninCell walls contain lignin Strengthening polymerStrengthening polymer SupportSupport ConductionConduction Allows plants to grow tallAllows plants to grow tall

Seedless Vascular PlantsSeedless Vascular Plants

Ferns & club mossesFerns & club mosses

Most important adaptation:Most important adaptation: Xylem – transports waterXylem – transports water Phloem – transports foodPhloem – transports food

Transport allows plants to grow largerTransport allows plants to grow larger

Club MossesClub Mosses Only group of vascular plants with Only group of vascular plants with

microphyllmicrophyll Leaf with single vascular strandLeaf with single vascular strand

True RootsTrue Roots Rhizome & aerial stemsRhizome & aerial stems Reproductive leaves with sporangiaReproductive leaves with sporangia

FernsFerns

Rhizome w/ rootsRhizome w/ roots

FrondsFronds

Sori found on frondsSori found on fronds Clusters of sporangiaClusters of sporangia Sporagenous cells undergo meiosis Sporagenous cells undergo meiosis

sporesspores

Fern Life CycleFern Life CycleProthallus

Homospory vs. Homospory vs. HeterosporyHeterospory

Homospory – sporophyte produces 1 Homospory – sporophyte produces 1 kind of sporekind of spore

Heterospory – microspores & Heterospory – microspores & megasporesmegaspores

Dominant StagesDominant Stages

Bryophyte – Gametophyte Bryophyte – Gametophyte

Seedless Vascular – SporophyteSeedless Vascular – Sporophyte

Gymnosperms – SporophyteGymnosperms – Sporophyte

Angiosperms - SporophyteAngiosperms - Sporophyte