Overview of the Plant Kingdom • Botanists divide the plant kingdom into four groups based on three important features: • Water conducting tissues • Seeds • Flowers
The Plant Life Cycle • Plants have life cycles that are characterized by alternation of generations • The two generations are the haploid (N) gametophyte, or gamete-producing plant, and the diploid (2N) sporophyte, or spore-producing plant.
Bryophytes • Type of early plant with no vascular tissue that draw water in their cells by osmosis.
In just a few million years, plants grew to a whole new scale on the landscape. Q: What caused this increase in size? A: Vascular Tissue
Vascular tissue • A type of tissue that is specialized to conduct water and nutrients through the body of the plant
Evolution of Vascular Tissue • Both forms of vascular tissue—xylem and phloem—can move fluids throughout the plant body, even against the force of gravity.
Xylem • Carry water upwards from the roots to every part of the plant
Phloem • Transports nutrients and carbohydrates produced by photosynthesis from the leaves down to the roots
Ferns Underground Stem
Over millions of years, plants with a single trait—the ability to form seeds—became the most dominant group of photosynthetic organisms on land. • Seed plants are divided into two groups:
Gymnosperms • Cone plants • Bear their seeds directly on the surfaces of cones Ex.) conifers, pines, spruces, cycads, ancient ginkgoes and gnetophytes
Angiosperms • Flowering plants • Bear their seeds within a layer of tissue that protects the seed Ex.) grasses, flowering trees shrubs, wild flowers
Monocots and Dicots • Monocots and dicots are named for the number of seed leaves, or cotyledons, in the plant embryo. Monocots have one seed leaf, and dicots have two seed leafs
Flowers • Seed bearing structures of angiosperms
Pollen Entire Male Gamtophyte
Pollen grain • Contains the male gamete
Pollination • The transfer of pollen from the male gametophyte to the female gametophyte