Kingdom Plantae
Characteristics of Plants • • • • • •
Eukaryotic Autotrophic Multicellular Cell walls (made of cellulose) Chloroplasts (containing chlorophyll) Store food as starch
Classification of Plants • Kingdom is subdivided into “divisions,” which are the equivalent of “phyla” • Plants vary in several ways: Presence of/absence of “vascular tissue” Dominant reproductive generation Production of pollen, spores, seeds, fruits, flowers o Whether or not water is necessary for reproduction o o o
Vascular vs. Non-vascular
• Vascular tissue consists of vessels, ducts, or tubes of elongated cells that conduct materials throughout the plant • Only vascular plants are considered to have “true” roots, stems, and leaves, the main vegetative organs of advanced plants
Vascular vs. Non-vascular
• “xylem”—tissue that conducts water and dissolved minerals up (from the roots) within a vascular plant
• “phloem”—tissue that conducts food (glucose) down (from the leaves) within a vascular plant
Life Cycle of Plants Alternation of Generation
Plants have a life cycle consisting of 2 phases, one of which is “dominant”:
• Gametophyte generation —produces sex cells “gametes”—sperm and egg cells); during “fertilization” a sperm cell and an egg cell unite to form a “zygote” • Sporophyte generation— produces cells called “spores” within “sporangia”
Major Plant Groups • Division Bryophyta—includes mosses
• Division Tracheophyta—includes ferns and their allies, gymnosperms and angiosperms
Division Bryophyta • Non-vascular plants; no xylem, phloem, or “true” roots, stems, or leaves • “Rhizoids” are root-like structures which anchor mosses in the ground and absorb water and minerals from the soil • Require water for reproduction (produce swimming sperm, not pollen) • Dominant gametophyte generation
Division Bryophyta • Gametophyte generation is leafy and green
Division Tracheophyta • Includes ferns, gymnosperms and the angiosperms. • Vascular plants; have xylem, phloem, and “true” roots, stems, and leaves • Dominant sporophyte generation
Gymnosperms • The word “gymnosperm” means “naked seed” • Mosses and ferns do not produce seeds, but gymnosperms and angiosperms do
• No requirement for water in reproduction; instead, they produce pollen • Produce 2 different types of spores: o
Microspores—male spores; become pollen
o
Megaspores—female spores; become eggs
Angiosperms • The word “angiosperm” means “seeds enclosed” • These plants produce seeds that are inside of fruits • Ex. Grass, oak, maple, iris, rose, buttercup, geranium • Angiosperms are also known as “flowering plants”
Angiosperms • Reproduce sexually by forming flowers, fruits, and seeds
The End