Kingdom_Plantae[1]

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