What Is a Plant? • Multicellular eukaryotes that are photosynthetic autotrophs • Cell walls made of cellulose • Store surplus carbohydrates as starch • Mostly terrestrial
Obstacles Plants Overcome • Absorb Minerals • Conserve Water • Cuticle • Stomata • Guard Cells • Reproduce on Land
A Vascular System Enables Plants to Thrive on Land • Most plants need a “plumbing” system to transport water, minerals and nutrients. This system is known as the VASCULAR SYSTEM.
Divisions of Living Plants Are Divided into Nonvascular and Vascular • There are 3 divisions of nonvascular plants • Hepatophyta – the Liverworts • Simplest of plants (gametophytes are dominate • Flat leafy body lacking cuticle, stomata, roots, stems or leaves • Anthocerophyta – the Hornworts • Dominate gametophyte and have stomata • Bryophyta – the mosses • Small, most have simple vascular tissue • Sporophyte with slender stalk and spore capsule • “leafy” green gametophyte that lacks roots, stems and leaves
Alternation Of Generations • Occurs in life cycle of all plants • One generation is a multicellular haploid condition and the next is a multicellular diploid condition
Gametes • Archegonia • Produce eggs • Antheridia • Produce sperm • When water is available, sperm swim to the eggs
Features of Vascular Plants • Dominate sporophyte • Specialized conducting cells • Distinctive body form • Meristem • Shoots • Roots
Evolution of the Seed • There are 5 phyla of living seed plants. Four of these phyla are collectively known as GYMNOSPERM. • The other phyla is ANGIOSPERMS.
Seed plants produce two kinds of gametophytes. • Microgametophyte – produce male • Megagametophyte – produce female – These develop from a megaspore within the ovule. • A pollen grain consists of only a few haploid cells surrounded by a thick protective wall.
Pollination • Wind • Insects • animals