DIVERSITY OF PLANTSDOMAIN – EUKARYA

KINGDOM - PLANTAE

PLANT KINGDOM• Plants are multicellular,

• Primarily terrestrial eukaryotes

• Autotrophic by photosynthesis

• Approximately 265,000 different types of plants exist today. Plants began the transition to land about 425 million years ago.

• Plants play a critical role as producers in the world's food webs; using photosynthesis to produce organic biomass and releasing oxygen as an end-product.

PLANT KINGDOM

• Terrestrial plants carry on gas exchange through pores (stomata) on the surface of leaves.

• Oxygen and water vapor leave thru stomata, and carbon dioxide enters through the stomata. (note: stoma (singular))

• The leaves are covered with a waxy cuticle to prevent desiccation.

PLANT KINGDOM

• Plant chloroplasts contain chlorophyll a, chlorophyll b, and a variety of yellow and orange carotenoids.

• Plant cell walls are composed of cellulose.

• Plants store carbohydrate as starch.

PLANT REPRODUCTION• Nearly all plants reproduce sexually, though many

also are capable of asexual modes of reproduction.

• Alternation of generations occurs in the life cycle of plants, with a haploid, gamete-producing gametophyte stage alternating with a diploid, spore-producing sporophyte stage.

• Bryophytes (true mosses) have a large, obvious gametophyte stage,

• but in other plants the sporophyte stage is larger and the gametophyte stage has been reduced.

ALTERNATION OF GENERATIONS

PLANT EVOLUTION - MARKED BY FOUR MAJOR ADAPTATIONS:

(1) about 400 million years ago - the feature of a protected embryo; also spore production as a means of reproduction;

(2) the evolution of vascular tissue;

(3) the origin of seed producing plants about 360 million years ago; and

(4) the evolution of flowering plants about 130 million years ago.

PLANT EVOLUTION

NONVASCULAR PLANTS – E.G. MOSSES

SEEDLESS VASCULAR – E.G. FERNS

SEEDLESS VASCULAR PLANTS

GYMNOSPERMS – VASCULAR PLANTS WITH SEEDS

ANGIOSPERMS – SEED FLOWERING

PLANTS - BASIC VOCABULARY

• vascular tissue - plant tissues that consist of cells that transport water and nutrients throughout the plant body. The two major types are xylem and phloem.

• xylem - vascular tissue that carries water and minerals from the roots to the rest of the plant.

• phloem - vascular tissue that carries sugar and organic nutrients (sap) throughout the plant.

• gametangium - the gametophyte stage of mosses consisting of a male antheridium (sperm) and a female archegonium (egg)

• gametophyte - multicellular, haploid stage of the life cycle that produces haploid gametes that fuse to form the diploid sporophyte

• sporophyte - multicellular, diploid stage of the life cycle that through meiosis produces haploid gametes that become the gametophyte

VASCULAR TISSUExylem - vascular tissue that carries water and minerals from the roots to the rest of the plant.

phloem - vascular tissue that carries sugar and organic nutrients (sap) throughout the plant.

Plant Kingdom: The Classification of Plants (Four major groups exist):

Bryophytes (mosses) and Relatives

Pteridophyta (Ferns) and Relatives

Gymnosperms and Relatives

Angiosperms and Relatives

Examples Mosses, liverworts, hornworts

Ferns, Psilotum (whisk fern), Lycopodium, Equisetum (horsetails)

Conifers, Gingko, cycads

Flowering plants, grasses, hardwoods

Vascular tissue (xylem and phloem)

Nonvascular Vascular Vascular Vascular

Sporophyte/ Gametophyte

Gametophyte (N) dominant

Sporophyte dominant, small separate Gametophyte

Sporophyte dominant

Sporophyte dominant

Reproduction(spores or seeds)

Spores Spores Seeds Seeds

Reproduction (Fertilization)

Water Water Wind(Pollination)

Wind/ animals (Flowers)

Reproduction (Seed/spore dispersal)

Water/ WindSpores

Water/ WindSpores

WindSeeds

Wind/animals(Fruits)Seeds

REDUCTION IN SIZE OF THE GAMETOPHYTE

NONVASCULAR PLANTS

Mosses and Relatives - – bryophytes

No true roots (rhizoids), stems, or leaves

Probably first land plants

Gametophyte stage dominant, no vascular tissue, spores as a means of reproduction

• For example, mosses, liverworts, hornworts

MOSS LIFE CYCLE

VASCULAR PLANTS: THE TRACHEOPHYTES

• Have vascular system (phloem (transport from upper plant to roots) and xylem (from roots to other plant parts)

• Appeared 350 million years ago (first forests)

• Have rhizomes, no true roots

VASCULAR PLANTS WITHOUT SEEDS

• Pteridophyta (plants without seeds)

• Example: ferns

• No seeds

• Pioneer plants

• Most prefer shaded, moist areas

FERN LIFE CYCLE

VASCULAR PLANTS WITH SEEDS

• New way to disperse – seeds

• Appeared about 280 million years ago (climate change)

• seed contains embryo; provides protection

• Most widely distributed of all plants

• At least 270 000 species known

life cycle of the pine

Phylum Coniferophyta

TWO TYPES OF SPERMATOPHYTES (SEED-

PRODUCING)

Gymnospermae and Angiospermae

Gymnospermae

-produce unprotected seeds in conelike structures (usually conifers)

- Wide rather than deep roots

- Examples: pines, spruces, junipers, cedars

- Alternation of generations producing pollen (vs. Spores in pteridophytes)

- Economic and medicinal value

CLASS: ANGIOSPERMAE• Alternation of generations produces seeds that are

borne in fruits

• More diverse than any all other plant classes combined

• There are monocots (one seed leaf) and dicots (two leaf seeds)

• Monocots – examples include Trillium, water lilies, orchids, onions

• Dicots – examples include asters, maples, peas, cabbage

ANGIOSPERMS AND THEIR RELATIVES

• Angiosperms (flowering plants) - the dominant form of plant life on earth at the present time; 240,000 species.

•monocots Monocotyledons

•dicots Dicotyledons

MONOCOTS MONOCOTYLEDONS•Consists of monocots (lilies, orchids, yuccas, palms, pineapples, grasses, and cereal grains) which have flower parts in threes or multiples of three (3); and

•one cotyledon (seed leaf) in their seeds

MONOCOT FLOWER, A DAYLILY

DICOTS DICOTYLEDONS

• dicots (oak, hickory, asters, roses, maples, strawberries, cactuses, beans) which have flower parts in four or fives, or multiples of four (4) or five (5), and

• two cotyledons (seed leaf) in their seeds

DICOT FLOWER, AN AZALEA

ANGIOSPERM CHARACTERISTICS

• Have well-developed and efficient vascular tissue including xylem (tracheids and vessels) and phloem (sieve tubes and companion cells).

• Four major flower parts may be present: the calyx consisting of sepals that protect the flower; the corolla consisting of petals to attract pollinators; the stamens (male pollen-producing structure consisting of and anther and filament); and the carpel (pistil) (female egg-producing structures consisting of the stigma, style, and ovary).

GENERAL FLOWER STRUCTURE - ANGIOSPERMS

pistil

male pollen-producing structure

female egg-producing structures

FLOWER DIVERSITY – MONOCOTS AND DICOTS

AngiospermFlowering plant life cycle

FOUR TRENDS IN ANGIOSPERM EVOLUTION

• 1. Number of floral parts has been reduced

• 2. Floral parts have become fused

• 3. Symmetry has changed from radial to bilateral

• 4. Ovary has dropped to a position below the petals and sepals (inferior) where the flowers are better protected

• * Flowering plants and land animals have co-evolved to develop many different types of relationships related to pollination and reproduction.

PLANT USES AND BENEFITS

PLANT USES AND BENEFITS

PLANT USES AND BENEFITS

PLANT USES AND BENEFITS

PLANT USES AND BENEFITS

PLANT USES AND BENEFITS

PLANT USES AND BENEFITS