Plants(K. Plantae)

Plant Basics

• Multicellular eukaryotes• Cell wall of cellulose• Photosynthetic (photoautotrophic)• Evolved from an organism similar to

today’s green algae• Need to survive

– 1. sunlight 2. water and minerals– 3. gas exchange 4. movement of water

& nutrients

Just how do plants move water and nutrients?

• Diffusion (if there is not a long way to go)

• Capillary action

• Vascular tissue – Xylem (water up from the roots)

• Tracheids

– Phloem (carbs down from the leaves)

Plant Life Cycle

The Nonvascular Plants • Low to the ground

• no vascular tissue

• gametophyte dominant

• antheridia (female parts) and archegonia (male parts)

The Nonvascular Plants • Division Bryophyta

– Mosses– Moist habitats with poor soils– Rhizoids (root like)

The Nonvascular Plants

• Division Hepaticophyta/ Hepatophya– Liverworts– Reproduce via gemmae– Thallus (body)

The Nonvascular Plants

• Division Anthocerophyta– hornworts

Seedless Vascular Plants

• Require water for reproduction

• Sporophyte dominant

• No seeds (spores instead)

• Vascular tissue

Seedless Vascular Plants

• Division Lycophyta– Club mosses (small plants in moist

woodlands)– Many are epiphytes (grow on trees but don’t

harm them)

Seedless Vascular Plants

• Division Arthrophyta– Equisetum (horsetail/ scoring rush)- abrasive

silica in stems, found in marshes

Seedless Vascular Plants

• Division Pterophyta– Ferns– Spores found in sori on the underside of

fronds

Seed Plants- General Info

• Do not require water for fertilization

• Gametophyte dominant

• Produce seeds

• Adaptations for reproduction– Flowers/ cones to protect seeds– Pollination– Protection of embryos in seeds

Seed Plants- Gymnosperms

• “naked seed”

Seed Plants- Gymnosperms

• Division Cycadophyta (cycads like the sago palm and palm trees)– Mycorrizhae

Seed Plants- Gymnosperms

• Division Gingophyta– Gingko biloba – the only extant member of

this division (“a living fossil”)– Male and female trees

Seed Plants- Gymnosperms

• Division Gnetophyta– Ephedra, Welwitschia

Seed Plants- Gymnosperms

• Division Coniferophyta (the conifers)– “cone-bearers”– Evergreens such as pines, firs

Seed Plants- Angiosperms

• Most diverse

• Division Anthophyta (“flowering plants”)

• More on flowers later…

Seed Plants- Angiosperms

• Monocots– Flower parts in 3’s– Examples: Lily, iris, grasses

Seed Plants- Angiosperms

• Dicots– Flower parts in 4’s or 5’s– Examples: rose, daisy, sunflower

Plant StructuresStoma- found on leaf surface; used for gas exchange; opening controlled by guard cells; transpiration can also occur through stomata

Plant Responses

• Tropism- response due to an environmental stimulus; controlled primarily by hormones– Phototropism- light– Gravitropism/ geotropism- gravity– Thigmotropism- touch

Plant Adaptations

• Aquatic Plants– Mangrove trees

• Desert Plants– Succulents– Thick coverings

• Carnivorous Plants– Pitcher plants (shape, color, smell)– Venus fly trap

• Parasitic Plants