Kingdom: Plantae

Characteristics of Plants

• Eukaryotic• Multicellular• Carry out photosynthesis• Cells have a cell wall made of cellulose• Mostly land dwelling • Develop from embryos that are protected by

tissues of parent plant

Life cycles

• Plants go through alternation of generations• One generation is haploid called gametophyte• One generation is diploid called sporophyte• Haploid spores produce plants which

eventually produce gametes which fuse to produce diploid zygote that grows into a sporophyte plant

• These generations can look quite different from one another

Five Major Groups of Plants

Green Algae

• Green algae has recently been reclassified as belonging to the Kindom Plantae

• Green algae has cell walls and photosynthetic pigments that are identical to plants

• Other algae remain in the Kingdom Protista

Five Major Groups of Plants

Seedless Non-Vascular PlantsMosses and Relatives

• These plants are known as Bryophytes• Grow close to the ground in damp locations• Do not have seeds or stems• Do not have any rigid support structures such

as lignin-reinforced cell walls • Do not have any vascular tissue to transport

water through the plant

Seedless Non-Vascular PlantsMosses and Relatives

• Bryophytes comprise nearly 10% of all plant species

• The gametophyte generation is the dominant generation

• Male and female gametes are produced in separate reproductive structures

• Sperm are flagellated and must swim through water to the eggs

Five Major Groups of Plants

Seedless Vascular Plants:Ferns and Relatives

• Contain conducting tissues called xylem and phloem which transport materials throughout the plant

• This development allowed the ferns to become tall and successful on dry land

• The dominant generation is sporophyte

Reproduction in Ferns

• Ferns produce gametes in structures on the underside of the gametophyte

• Ferns need water to complete their life cycle because sperm have to swim through a film of water to fertilize the eggs

• The brown “dots” on the underside of the mature (sporophyte) fronds are spore capsules containing many haploid spores that will produce gametophytes

Five Major Groups of Plants

Seed-producing Vascular plantsGymnosperms

• Conifers such as pine, fir, spruce, redwood and cedar trees – cone bearing plants

• Plants that bear “naked” seeds – seeds not enclosed in an ovary (fruit)

• Seeds are plant embryos covered in a protective coat along with food

• The gametophyte is smaller than in ferns and mosses

Gymnosperm

Reproduction in Gymnosperms

Five Major Groups of Plants

Flowering Plants Angiosperms

• The reproductive structures are the flowers• Angiosperm means “enclosed seed”• The gametophytes develop within the flowers

of angiosperms• Flowers have many adaptations that attract

organisms to help transfer pollen• Once pollination occurs, the ovary develops

into a fruit

Angiosperm fruit

Life cycle of an Angiosperm

Parts of a FlowerStigma

Style

Ovary

Carpel/Pistil

(female) Anther

Filament

Stamen (male)

petals

ovule

sepal

Five Major Groups of Plants