Plant Diversity

What are Plants? Multicellular (made of many cells) Eukaryotes (cells have nucleus & organelles) Cell Walls made of Cellulose Autotrophs –Photosynthetic using chlorophyll a & b

Survival Plants need 4 things: 1)Sunlight: without light they cannot get energy 2)Water & Mineral: needed for photosynthesis 3)Gas Exchange: take in CO 2 & let out O 2 4)Movement of Water & Nutrients: food made by plant needs to get to all parts of the plant

First Plants What organism have we covered that looks like a plant? –Multicellular GREEN ALGAE –Thought to have started in the ocean

Mosses & Bryophytes Non-vascular Plants –Don’t have tissues transporting water through them Dependent on Water –Take in water through osmosis Bryophytes Include: –Mosses, Liverworts, & Hornworts

1)Mosses 2) Liverworts 3) Hornworts

Seedless Vascular Plants Include: –Club Mosses –Horsetails –Ferns Most numerous Have true roots, leaves, & stems

Vascular Tissue Vascular Tissue: –transfers water & nutrients through the plant Traicheids: cells specialized to move water Xylem: cells that move water up the plant Phloem: cells that move nutrients and carbohydrates made by photosynthesis

True Integral Parts These are the 1 st plants to show: –True Roots: underground organs that absorb water and minerals –True Leaves: photosynthetic organs that contain vascular tissues –True Stems: supporting structures that connect roots and leaves; carry water

Seed Plants Can reproduce without water! Why? –They have flowers or cones –Transfer sperm by pollination –Embryo is protected in seed

Types of Seed Plants Two Types: –Gymnosperms have seeds directly on surface of cones –Angiosperms (Flowering Plants) have seeds that are protected by a layer of tissue (i.e. Fruit: has tissue around seed)

Angiosperms 2 Types: Dicots & Monocots

Life Span Three Categories: –Annual: flowering plants that complete life cycle in one growing season –Biennial: complete their life cycle in two years –Perrenial: flowering plants that live more than 2 years