Inquiry into Life Twelfth Edition Lecture PowerPoint to accompany Inquiry into Life Twelfth Edition Sylvia S. Mader Chapter 29 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

29.1 Evolutionary History of Plants Plants evolved from algae over 500 million years ago Characteristics plants and algae share Contain chlorophyll a and b and accessory pigments Store excess carbohydrates as starch Have cellulose in their cell walls Biochemical evidence shows plants are most closely related to stonewarts, a type of green algae

29.1 Evolutionary History of Plants Four Major Events in Evolution of Plants Development of embryo protection Development of vascular tissue Development of seeds Development of flowers

Evolutionary History of Plants

29.1 Evolutionary History of Plants Alternation of Generations All plants have a life cycle that included the alternation of generations Sporophyte (2n) Gametophyte (n) Plants differ as to which generation is dominant (most conspicuous)

Alternation of Generations

Reproduction in the Size of the Gametophyte

29.2 Nonvascular Plants Nonvascular plants lack true roots, stems, and leaves By definition, roots, stems, and leaves have vascular tissue The gametophyte generation is dominant Three divisions Hornworts Liverworts Mosses

29.2 Nonvascular Plants Liverworts Two basic types: “leafy” and those with a flat, lobed thallus Marchantia- thallus type Smooth upper surface Lower surface has many rhizoids which extend into soil Reproduce both sexually and asexually Asexual reproduction by gemmae- groups of cells that detach and form new thallus Sexual reproduction by gametophores- structures that produce gametes

Liverwort, Marchantia

29.2 Nonvascular Plants Mosses Found all over the world Mosses become dormant if the environment becomes dry Most mosses can reproduce asexually by fragmentation in addition to sexual reproduction

Moss Life Cycle, Polytrichum sp.

29.2 Nonvascular Plants Adaptations and Uses of Nonvascular Plants Can live on bare rock, fences, cracks of sidewalks Selective advantage to being small and simple Help convert rocks to soil Peat moss Used as fuel Holds water Used in gardens to improve soil

29.3 Seedless Vascular Plants Seedless vascular plants include whisk ferns, club mosses, horsetails, and ferns The sporophyte is the dominant generation Vascular tissue Xylem Conducts water and minerals up from the soil Phloem Transports organic nutrients between parts of the plant Seedless vascular plants formed the swamp forests of Carboniferous period

The Carboniferous Period

29.3 Seedless Vascular Plants Whisk Ferns- Psilophyta Arial stem with many forks Attached to rhizome- underground stem No leaves, photosynthesis occurs in stems Independent gametophyte found underground

29.3 Seedless Vascular Plants Club Mosses Rhizome sends up aerial stems Scale-like leaves Some are epiphytes Live on trees but do not parasitize them

29.3 Seedless Vascular Plants Horsetails Moist habitats world wide Rhizome produces aerial stems In some species, whorls of side-branches come off the main stem at regions called nodes Leaves are scale-like Cones are at tips of stems in most Have silica deposited in cell walls

29.3 Seedless Vascular Plants Ferns Most abundant in warm, moist, tropical regions Leaves are called fronds Immature leaves are called fiddleheads Grow from rhizome Dominant sporophyte stage Produces wind-blown spores Spore germinates and forms small gametophyte Independent from the sporophyte Swimming sperm produced by antheridia Fertilization occurs in archegonia

Fern Life Cycle

Fern Diversity

29.4 Seed Plants Gymnosperms and Angiosperms Seeds contain a sporophyte embryo and stored food within a protective coat This allows an embryo to survive during long periods of dormancy

29.4 Seed Plants Gymnosperms Exhibit heterospory Two types of spores- produce two types of gametophytes, male and female Pollen grains- male gametophyte Pollination-deposition of pollen on a female gametophyte Pollen tube-sperm pass through pollen tube to reach ovule No water required as it is in previous groups Female gametophyte develops within ovule

Pine Life Cycle

29.4 Seed Plants Gymnosperms Adaptations and Uses of Conifers Conifers are the most familiar gymnosperms Pines, spruces, firs, cedars, hemlocks, redwoods, and cypress Adaptations and Uses of Conifers Adapted to cold, dry weather Pollen cones and seed cones are adaptations to land Needle-shaped leaves have small surface area to decrease water loss Also have a thick cuticle and recessed stomata Wood is used in construction and for making paper Resins are used for production of chemicals

Conifers

29.4 Seed Plants Other Gymnosperms Cycads Gingkoes Gnetophytes Resemble palms or ferns Pollen or seed cones grow on top of long vertical stem Plentiful in Mesozoic era at the time of dinosaurs Gingkoes Only one surviving species-Gingko biloba, the maidenhair tree Female trees produce fleshy seeds that give off a foul odor Male trees are preferred for ornamental planting Gnetophytes Ephedra is only species in N. America Adapted to hot temperatures

Other Gymnosperms

29.4 Seed Plants Angiosperms Angio (vessel), sperm (seed) There are more known species of angiosperms than all other types of plants combined Live in all types of habitats Seed develops from an ovule within an ovary Ovary becomes the fruit Two classes: Monocots and Eudicots

Flower Diversity

29.4 Seed Plants The Flower Flower parts Receptacle: tip of stalk that bears flowers Sepals: modified leaves that protect bud Petals: modified leaves, may be colorful Stamens: male reproductive structures Anther: pollen production Filament Carpels: female reproductive structures Stigma: for reception of pollen Style Ovary: ovule production

Generalized Flower

Flowering Plant Life Cycle

29.4 Seed Plants Life cycle, Adaptations, Uses of Flowering Plants Pollination can be by wind, water, insects, and other animals such as bats Fruits, the final product of a flower aids in the dispersal of seeds.

Fruits