What Is a Plant? Multicellulareukaryotes 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
GametesArchegonia – Produce eggsAntheridia – Produce spermWhen water is available, sperm swim to the eggs
Features of Vascular PlantsDominate sporophyteSpecialized conducting cellsDistinctive body form – Meristem • Shoots • Roots
Evolution of the SeedThere 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.