Kingdom Plantae Kingdom Plantae IntroductionIntroduction

CharacteristicsCharacteristics

There are more than 280,000 plant species on There are more than 280,000 plant species on EarthEarth

PhotosyntheticPhotosynthetic Cell walls made of celluloseCell walls made of cellulose Stems and leaves are coated with a waxy Stems and leaves are coated with a waxy

cuticle that prevents dessication (drying out)cuticle that prevents dessication (drying out) Oxygen and carbon dioxide are exchanged Oxygen and carbon dioxide are exchanged

between plants and their environment and gas between plants and their environment and gas exchange occurs through tiny openings in the exchange occurs through tiny openings in the leaf called stomataleaf called stomata

Stomates and Guard CellsStomates and Guard Cells

What evidence is there that plants What evidence is there that plants evolved from green algae evolved from green algae (Chlorophytes)?(Chlorophytes)? Homologous chloroplasts with chl a, chl b Homologous chloroplasts with chl a, chl b

and caretonoids and caretonoids Biochemical similarities such as cellulose as Biochemical similarities such as cellulose as

the cell wall structurethe cell wall structure Food stored as starch Food stored as starch Similar cell plate formation Similar cell plate formation Similar sperm structure Similar sperm structure Similar genes and rRNA’s Similar genes and rRNA’s

Advantages to LandAdvantages to Land Lots of roomLots of room Lots of light and gasesLots of light and gases Soil rich in nutrientsSoil rich in nutrients Originally no herbivores on landOriginally no herbivores on land

5 Characteristics of All Plants5 Characteristics of All Plants

1. All plants have an 1. All plants have an apical meristem. apical meristem. This is the tip of the This is the tip of the root and the shoot. root and the shoot. All cell division All cell division occurs here.occurs here.

2. All plants have 2. All plants have cuticles, stomata, and cuticles, stomata, and mechanisms to move mechanisms to move water throughout water throughout their bodies.their bodies.

5 Characteristics of all Plants5 Characteristics of all Plants

All plants undergo alternation of generationsAll plants undergo alternation of generations3.3. All plants have a sporophyte (2n) generation All plants have a sporophyte (2n) generation

with cells that undergo meiosis to produce with cells that undergo meiosis to produce haploid spores (n).haploid spores (n).

4.4. These spores grow into multicellular These spores grow into multicellular gametophytes which produce gametes (n). gametophytes which produce gametes (n). The male gametophyte is called the The male gametophyte is called the antheridium, while the female gametophyte is antheridium, while the female gametophyte is called the archegonium.called the archegonium.

5.5. The male and female gametes fuse to form The male and female gametes fuse to form the sporophyte (2n).the sporophyte (2n).

Alternation of Alternation of GenerationsGenerations

Moss generations…Moss generations…

Moss generations…Moss generations…

Sporophyte close up…Sporophyte close up…

Male gametophytes Male gametophytes (antheridia with sperm (antheridia with sperm “gametes”)“gametes”)

Close up of antheridium Close up of antheridium with sperm.with sperm.

Archegonium with egg Archegonium with egg (gamete)…(gamete)…

Fertilization…Fertilization…