THE PLANT KINGDOM THE PLANT KINGDOM
Jan 12, 2016
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