 Science Starter  Life as we know it today could not exist without plants. Plants provide us with many essential items other than food.  1.With your partner, list five items you use daily that are byproducts of plants. Section 22-1 Go to Section:

 22–1Introduction to Plants A.What Is a Plant? B.The Plant Life Cycle C.What Plants Need to Survive 1.Sunlight 2.Water and Minerals 3.Gas Exchange 4.Movement of Water and Nutrients D.Early Plants 1.Origins in the Water 2.The First Plants E.Overview of the Plant Kingdom Section 22-1 Go to Section:

 What do we already know about plants? How many cells? Eukaryote or prokaryote? How do they get food? Special structures in cells?

 Plants are multicellular eukaryotes that have cell walls, made of cellulose.  They develop from multicellular embryos  Carry out photosynthesis using green pigment called chlorophyll.  They are autotrophs  Examples:

 “Stationary animals that eat sunlight!”  Differences between plants and animals:

 Two generations: The haploid (N) gametophyte, or gamete- producing plant The diploid (2N) sporophyte, or spore- producing plant  Spores are reproductive cells that produce a new individual by mitosis.  This may differ dramatically from phylum to phylum!

Haploid Diploid MEIOSIS Spores (N) Sporophyte Plant (2N) Gametophyte Plant (N) FERTILIZATION Sperm (N) Eggs (N) Section 22-1 Go to Section:

 Sunlight To carry out photosynthesis Typically photosynthetic organs such as leaves are broad and flat to maximize light absorption.  Water and Minerals Water also needed for photosynthesis Minerals can only be taken in through water Adaptations to limit water loss

 Gas Exchange Oxygen needed to support respiration Carbon dioxide needed for photosynthesis The problem: Exchange these gasses without losing a lot of water  Movement of Water and Nutrients Absorption happens at roots, but must move throughout entire plant Specialized tissues OR Diffusion

 Read p. 553 first two paragraphs!  Origins in the Water: The first plants evolved from an organism much like the multicellular green algae living today  The First Plants: Read paragraph 2 on page 554

Flowering plants Cone-bearing plants Ferns and their relatives Mosses and their relatives Green algae ancestor Flowers; Seeds Enclosed in Fruit Seeds Water-Conducting (Vascular) Tissue Section 22-1 Go to Section:

 Divided into FOUR groups, based on three important features: fig water-conduction tissues 2. seeds 3. flowers 

Cone-bearing plants 760 species Ferns and their relatives 11,000 species Mosses and their relatives 15,600 species Flowering plants 235,000 species Section 22-1 Go to Section:

 22–2 Bryophytes A.Groups of Bryophytes 1.Mosses 2.Liverworts 3.Hornworts B.Life Cycle of Bryophytes 1.Dependence on Water 2.Life Cycle of a Moss C.Human Use of Mosses Section 22-2 Go to Section:

 Byrophytes AKA nonvascular plants Do not have vascular tissues (tissue that are responsible for conducting water and nutrients)  Have a life cycle that depend on water for reproduction.  Draw up water by osmosis Can only be a few centimeters off the ground Example: Mosses

 Characteristics: Must be low growing Usually found in shaded or moist areas  Include: Mosses Liverwarts Hornwarts

 Most common bryophyte  Belong to phylum Bryophyta  Grow near water  Do not have true roots, instead they have: Rhizoids: long thin cells that anchor plant into the ground, helps to absorb water and minerals from surrounding soil

Rhizoid Capsule Stalk Sporophyte Gametophyte Stemlike structure Leaflike structure Section 22-2 Go to Section:

 Looks like a flat leaf, attached to the ground (shaped like a liver)  Phylum: hepaticophyta  Reproduce asexually by gemmae Small multicellular spheres that contain haploid cells. These cells are washed off the parent plant, and they then begin a new plant

 The gametophyte is the dominane, recognazible stage of the life cycle, and it’s the stage that carries out most of the plant’s photosynthesis  For fertilization to occur, there must be WATER!

 Read page #558  Protonema: after a BRYO reporduces, it germinates and begins a tangles mass of green filimants  Antheridia: part of BRYO where sperm are produced  Archegonia: part of BRYO where the egg is produced

Haploid (N) Diploid (2N) MEIOSIS FERTILIZATION Mature sporophyte (2N) Gametophyte (N) Young sporophyte (2N) Zygote (2N) Sperm (N) Egg (N) Spores (N) Capsule (sporangium) Protonema (young gametophyte) (N) Male gametophyte Female gametophyte Antheridia Archegonia Go to Section:

 22–3Seedless Vascular Plants A.Evolution of Vascular Tissue B.Ferns and Their Relatives 1.Club Mosses 2.Horsetails 3.Ferns C.Life Cycle of Ferns Section 22-3 Go to Section:

 Vascular tissues: specialized tissue used to conduct water and nutrients through the body of the plant. These types of plants can grow taller  Were byrophytes vascular or nonvascular plants?

 Two types of Vascular Tissue: Xylem: conducts water upwards from roots to every part of thee plant Phloem: transports nutrient solutions  Both of these can work against the force of gravity.  Vascular plants produce lignin the substance that make cell wall rigid. Lignin allows vascular plants to grow upright and reach great heights.

 Seedless vascular plants include mosses, horsetails and ferns.  These all have true: Roots: underground organs that absorb water and minerals. Leaves: contain bundles of vascular tissues, photosynthesis is carried out here. Veins: composed of xylem and phloem Stems: supporting structures that connect roots and leaves. Carry water and nutrients between them.

 More than 11,000 species of ferns  Evolved over 350 million years ago.  Page #562 diagram of a fern The large leaves = Fronds Rhizomes: creeping under ground stems

 Ferns and other vascular plants have a life cycle in which the diploid sporophyte is the dominant life stage.  Sori: spores release from sporangia. Must be carried by wind or water. Looks like rust spot underside of the frond

Haploid gametophyte (N) Diploid sporophyte (2N) MEIOSIS FERTILIZATION Mature sporophyte (2N) Gametophyte (N) Frond Sperm Egg Spores (N) Antheridium Archegonium Developing sporophyte (2N) Sporophyte embryo (2N) Mature gametophyte (N) Young gametophyte (N) Sporangium (2N) Section 22-3 Go to Section:

 22–4Seed Plants A.Reproduction Free From Water 1.Cones and Flowers 2.Pollen 3.Seeds B.Evolution of Seed Plants C.Gymnosperms—Cone Bearers 1.Gnetophytes 2.Cycads 3.Ginkgoes 4.Conifers 5.Ecology of Conifers Section 22-4 Go to Section:

 Seed Plants are divided into two groups: Gymnosperms: bear their seed directly on the surfaces of cones  Examples: Conifers (pine and spruce trees) Angiosperms: (AKA flowering plants) bear their seeds within a layer of tissue that protects the seed.  Examples: grasses, flowering trees, shrubs, wildflower 

 Still have alternating life cycle b/t gamete and sporophyte stages.  Seed plants DON’T need water to reproduce! This means seed plants can live about anywhere  Adaptations that allow seed plants to reproduce without water include: flowers or cones, the transfer of sperm by pollination and the protection of embryos in seeds.

 Seed plants do not require water for fertilization.  Adaptations that allow this include: Flowers or cones Transfer of sperm by pollination Protection of embryos in seeds

 Cones: seed-bearing structures of gymnosperms  Flowers: seed-bearing structure of angiosperms.

 The entire male gametophyte is contained in a tiny structure called pollen grain. This PG is carried to the female gametophyte by wind, insects, birds, etc.  This transfer of pollen from the male to the felmale gametophyte is pollination

 Seed: embryo of a plant, encased in a protective covering and surrounded by a food supply.  After fertilization the zygote contained with in the seed grows into a tiny plante called the embryo.

Seed coat Embryo Stored food supply Seed Wing A B Section 22-4  The embryo the early developmental stage of the sporophyte The seed coast surrounds and protects the embryo and keeps it from drying out! Go to Section:

 Read Evolution of Seed plants p. 566  Gymnosperms Reproduce with seeds that are exposed Means “naked seed” Conifers are most common in our area  Pine, spruce, cedars, redwoods, etc. Ginkgoes – read p. 567

Comparing Features of Seed Plants Feature Seeds Reproduction Examples Feature Seeds Reproduction Examples Section 22-4 Go to Section: GymnospermsAngiosperms

Comparing Features of Seed Plants Feature Seeds Reproduction Examples Feature Seeds Reproduction Examples Section 22-4 Go to Section: GymnospermsAngiosperms Bear their seeds on cones Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination Conifers, cycads, ginkgoes, gnetophytes Bear their seeds within flowers Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination Grasses, flowering trees and shrubs, wildflowers, cultivated flowers

 22–5Angiosperms— Flowering Plants A.Flowers and Fruits B.Diversity of Angiosperms 1.Monocots and Dicots 2.Woody and Herbaceous Plants 3.Annuals, Biennials, and Perennials Section 22-5 Go to Section:

 Flowering plants originated on land and quickly came to dominate life  Angiosperms have reproductive organs known as flowers. Evolutionary advantage – transport of pollen More efficient than wind pollination of GSperm  Asperms contain ovaries, witch surronund and protect the seed Asperm actually means “enclosed seed”

 Figure page 569  Fruit: a thick wall of tissue surrounding the enclosed seed. Animals spread the seed by eating fruit and “depositing” seed at another location Another evolutionary advantage!

 Classification by 3 groups  These groups can overlap 1. Monocots and dicots 2. Woody and herbaceous 3. Life cycle

 Monocotyledonae  Dicotyledonae  Figure page 570

MonocotsDicots Seeds Leaves Flowers Stems Roots Single cotyledon Parallel veins Floral parts often in multiples of 3 Vascular bundles scattered throughout stem Fibrous roots Two cotyledons Branched veins Floral parts often in multiples of 4 or 5 Vascular bundles arranged in a ring Taproot Section 22-5 Go to Section:

 Based on stem characteristics  Woody plants: thick cell walls that support plant. Trees & shrubs  Herbaceous plants: must be smooth and nonwoody. Dandelions, petunias, sunflowers, geraniums

 3 groups based on length of time  Read page 572  Annuals: plants that complete life cycle in one year EX: marigolds, petunias, zinnias  Biennial: Year one grow and generate roots. Year two produce flowers and seeds, then die Parsley, celery and foxglove  Perennial: Live for many years.

are categorized as that complete their life cycle in Section 22-5 Plants AnnualsPerennials 2 years Go to Section:

are categorized as that complete their life cycle in Section 22-5 Plants Annuals Biennials Perennials 1 growing season 2 years More than 2 years Go to Section: