Kingdom Plantae An Evolutionary History of Plants

Life on Earth: The First Forests Complete the information on the next two slides (also shown on the handout provided in class) as you view the film.

From the film, list the order of development of the members of the plant kingdom. _______________________________ _______________________________ _______________________________ _______________________________ _______________________________ _______________________________

Circle the group(s) that exhibit each of the properties listed below. Require water for swimming gametes mosses club mosses ferns cycads conifers angiosperms Possess a vascular system mosses club mosses ferns cycads conifers angiosperms Produce spores mosses club mosses ferns cycads conifers angiosperms Produce seeds mosses club mosses ferns cycads conifers angiosperms

Algae are the Ancestors of Plants Liverworts Nonvascular plants (bryophytes) Origin of land plants (about 475 mya) Land plants Ancestral green alga 1 Hornworts Mosses Lycophytes (club mosses, spike mosses, quillworts) plants vascular Seedless Origin of vascular plants (about 425 mya) 2 Vascular plants Pterophytes (ferns, horsetails, whisk ferns) Gymnosperms Origin of seed plants (about 360 mya) 3 Seed plants Angiosperms 500 450 400 350 300 Millions of years ago (mya)

Characteristics of Plants Eukaryotic Multicellular Autotrophic: photosynthetic Sexual and asexual reproduction Cell wall made of cellulose Usually non-motile except for gametes Adapted to life on land

Adaptations to Life on Land Roots and root-like structures Conduction vessels Structural support Water-proof covering Pores for gas and water exchange Mechanisms for dispersal of reproductive products

Evolutionary Tree of Major Plant Groups Vascular Plants Evolutionary Tree of Major Plant Groups Non-vascular Plants Seed Plants Liver- worts Gymno- sperms Angio- sperms Mosses Ferns Evolutionary tree of some major plant groups Flowers & Fruits appear Shows increasing adaptations for land dwelling True vascular tissue and lignin appear Seeds and pollen appear Ancestral Algae

Plant Life Cycle: Alternation of Generations Gametes form by mitosis Gametophyte n Spores form by meiosis Haploid n Sperm Gametes meet & fuse to form zygote n Spores Egg n n n n Diploid 2n 2n Zygote Spore Mother Cell 2n Sporophyte 2n Embryo Evolutionary trend: reduction of gametophyte

Bryophytes: Mosses No fluid-conducting vascular system Enclosed reproductive structures Require moist environments Sporophyte (stalk) Female Gametophyte (leafy)

Vascular Plants Specialized groups of conducting cells organized into vessels Functions of vessels conduct water and nutrients provide support to plant body with lignin Largest group of plants

Vascular Plants: Ferns Seedless vascular plants Tall leafy Sporophyte Gametophyte requires moist environment Gametophyte Archegonia produce eggs Antheridia produce sperm

Fern Life Cycle Mature Sporophyte meiosis Spore Case mitosis, differentiation, growth mitosis, differentiation, growth Young Sporophyte Egg growth mitosis, differentiation, growth Fern Life Cycle Mature Gametophyte Zygote Diploid 2n fusion to form zygote Haploid 1n Sperm

Vascular Plants: Gymnosperms Seed-producing vascular plants Pollinated by wind Conifers adapted to cold, dry climate cones to protect seeds evergreen waterproof needle-like leaves sap does not freeze

Vascular Plants: Gymnosperms Coastal Redwood (Tallest Trees) Giant Sequoia (Largest Living Thing)

Two Uncommon Gymnosperms Cycad These plants have separate sexes, ie. male and female plants. Gingko

Vascular Plants: Angiosperms Seed and fruit-producing vascular plants Broad, waterproof leaves Modified leaves = Flower = reproductive structure Many have animal pollinators; some use wind Greatly reduced gametophyte (pollen grain and embryo sac with egg) Largest number of species (250,000)

Applying Your Knowledge Mosses Ferns Gymnosperms Angiosperms Which group of plants Encloses seeds within fruit? Does not have a vascular system? Protects seeds within a cone? Has a vascular system but does not produce seeds?