Introduction to Plants Mr. Hamer’s Hooligans

Earliest Plants Algae Phytoplankton Lived in the sea

Problems with life on land Drying Out Making Food Reproduction Gravity & support Obtaining water & nutrients Solution ☺ Waxy cuticle, stomata Formed leaves Develop spores/seeds Bark & vascular tissue Roots & vascular tissue

Types of Plants Non-vascular plants Vascular Bryophytes (mosses) Contain vessels for transporting nutrients and support

The Bryophytes - Mosses First land plants NON VASCULAR (and so very small) Developed 500 m.y.a. Required moist environments Used for fuel (peat)

Pterophytes - Ferns Developed 400 m.y.a. Structure Rhizome = underground stem Fronds = leaves

Tracheophytes Vessels Spores or seeds for reproduction XYLEM = transports water & dissolved minerals from roots to leaves PHLOEM = transports sugars from leaves to rest of plant Spores or seeds for reproduction

Gymnosperms Gymno = “naked” Sperm = “seed” a.k.a “Cone-bearing” plants First plants to produce seeds No flowers No fruit

Why Make Seeds? Has own food supply Protective coat against harsh conditions Some are designed for travel to new areas

Coniferophyta Needle or scale-like leaves Bear seeds in woody cones Can live in very cold climates Most are evergreens Have wood Made of thick-walled vessels (tracheids) Tracheids are xylem and phloem

Angiosperms Angio – “flower” Sperm – “seed” Extremely diverse All have seeds enclosed in fruit

Overall Structures (see ch. 23) Roots Stems Leaves Flowers

Roots Absorb water & nutrients Hold plant in place Root types: Fibrous Tap

Stems Support leaves & flowers Sometimes photosynthesis Transport (contain xylem & phloem) Types herbaceous – green & flexible woody – stiff, have cork layer, brown

Leaves Cuticle = protection Stomata = gas exchange, water loss Epidermis = protection, color Mesophyll = PHOTOSYNTHETIC LAYER