sheryl searcy ninth grade center 2013 introducing plants section 22-1

Sheryl Searcy Ninth Grade Center 2013

INTRODUCING PLANTS

Section 22-1


Criteria for Kingdom Plantae Cell type: Eukaryotes. Cell structure: Cell wall made of cellulose. Cell number: Multicellular. Mode of nutrition: Autotrophic. Carry out photosynthesis using the green

pigments chlorophyll a and b. Some are parasitic or saprobes.


Plant Life Cycle

Textbook, page 552

All plants have a life cycle with

alternation of generations, in

which the haploid

gametophyte phase

alternates with the diploid

sporophyte phase.


Plant Life CycleAlternation of Generations! Haploid (N)

– Gametophyte plant (N) – Produces either sperm or eggs.

(gametes = reproductive cells)

Diploid (2N)– The sperm and egg join to create the

Sporophyte plant (2N), which is diploid. – Egg and sperm join to create spores by

meiosis.


Evolutionary Cladogram of Plants

(Angiosperms)

(Gymnosperms)

(Bryophytes)


Plant Survival Sunlight needed to carry out photosynthesis. Minerals and water are needed to make

new plant parts. Gas exchange (through photosynthesis and

cellular respiration) must occur without losing excessive amounts of water.

Movement of water and nutrients is required for plant energy production and growth.


Overview of the Plant Kingdom

The majority of plant life is ______________.


BRYOPHYTESSection 22-2


Bryophytes (ex. mosses, liverworts, hornworts)

Life cycles depend on water for reproduction.

Abundant in moist environments (bogs, near streams, in rain forests) because there is no vascular tissue.

Sphagnum moss alive is used in gardening, and when compacted (peat) it’s used for fuel.


Typical Moss Plant

Capsule

Stalk

LeaflikeStructure

StemlikeStructure

Rhizoid

Sporophyte

Gametophyte


Life Cycle of a Moss


FERNS:Seedless Vascular Plants

Section 22-3


What developed between plant divisions 1 and 2?

Vascular Tissue developed!

Vascular tissue: specialized tissue to transport water and nutrients throughout the plant.


Phylum Pterophyta: Ferns Ex. horsetails, club mosses, ferns. Leaves are called fronds. Undergound stems called rhizomes . Found in moist, shaded forest areas. Sori – clusters of sporangia (spores

on the underside of fronds).


Vascular Tissue Tracheids are specialized cells that can move

fluids through the plant body, even against the force of gravity.– Xylem (moves water

upward).– Phloem (moves

nutrients and carbohydrates throughout

the plant).


Typical Fern Plant


Life Cycle of a Fern


GYMNOSPERMS:Seed Plants

Section 22-4


Gymnosperms: Cone Bearers Means “naked seed”. Includes conifers (pines

& spruces) and palms (cycads & ginkgoes).

Second evolutionary development: Adapted seed to allow reproduction without water; able survive in dry and extreme temperatures.


Reproduction Germination: early growth stage of a

plant embryo. Dormancy: period of time during which a

plant embryo is alive but not growing. Features that allow seeds to reproduce

without water:– Reproduction in cones.– Movement of gametes by pollination.– Protection of embryo in a seed.


Diagram of a Pine Seed

Embryo

Endosperm

Seed Coat

Embryo– Growing part of

seed Endosperm

– Tissue that provides nutrition for the developing seed.

Seed Coat– Protective outer

covering of the seed.


Pollination Transfer of pollen from the male

reproductive structure to the female reproductive structure.


Adaptations of Gymnosperms Needles

Winged Seeds


ANGIOSPERMS:Flowering Plants

Section 22-5


Anthophyta: Angiosperms Dominate plant life. Flowers are the reproductive

organs of plants.– has ovaries (fruit) to

protect the seeds.– Attracts animals which

help with pollination.


Diversity of AngiospermsCan be classified into:

1. Stems: herbaceous vs. woody.2. Lifespans: annuals, biennials, perennials.3. monocotyledon vs. dicotyledon.


Monocots vs. Dicots


Lifespans Annuals

– Complete life cycle in one year. Biennials

– Life cycle takes 2 years Year one: germinate and grow roots, maybe leaves. Year two: grow new stems, leaves, and flowers.

Perennials– Live through many years

May die back in winter, but re-grow in the spring (asparagus, peonies, many grasses).

Most have woody stems (palms, trees, honeysuckle).


Examples of Monocotyledons(Liliopsida)

Grasses which include grains such as corn and wheat.

Lilies. Orchids. Palms.


Examples of Dicotylendons(Magnoliopsida)

Roses Mallows Tomatoes Oaks Daisies


Plant Parts Transport

– Roots, stems, leaves. Energy Production

– Leaves. Reproduction

– Flowers.


Roots (Transport)

Taproot: primary root grows down from the stem with secondary roots forming.– ex. carrot, potato, radish

Fibrous: small lateral roots that spread out just below surface of the soil.– ex. weeds


4 Root Functions Absorbs water & nutrients from the soil. Transports water & nutrients to stem. Anchors plant to maintain stability. Stores food and water.


Outermost layer of cells

Within cortex; contains cells for transport of water, nutrients, & minerals)

Site of absorption

Tissue that stores starch

Protection of root tip

Structure of Roots


Stems (Transport) Woody

– Thick cell walls that support the plant.

– Trees, shrubs, and vines. Herbaceous

– Stems are smooth, supported by hydrostatic pressure (turgor).

– Dandilions, zinnias, petunias.


Stems


3 Functions of Stems Transports water & nutrients from roots

to leaves. Supports/produces leaves, branches,

fruits/flowers. Stores food.


Transport in Plants Capillary action: the

tendency of water to rise in a thin tube.

The result of the water molecules’ ability to stick to one another (cohesion)and to the walls of the tube (adhesion).

Contributes to the movement of water up the cells of the xylem tissue.


Leaves (Transport & Energy Production) Photosynthesis

– Process that plants use to produce their food.– 6CO2 + 6H2O C6H12O6 + 6O2

Transpiration– Loss of water and exchange of carbon dioxide.


Cuticle– Waxy outer surface;

retains moisture. Mesophyll

– Middle layer of leaf where photosynthesis occurs.

– Palisade layer (upper).– Spongy layer

(underside).

Structure of Leaves


Epidermis – “Skin” of leaf -

responsible for gas exchange.

– Upper and lower. Stomata

– Outside layer of leaf opening in epidermis where gas and water exchange (controlled by guard cells).

Structure of Leaves (cont’d)


Gas Exchange in Leaves

Turgor pressure (water pressure)– Stomata close automatically when supplies of

water from roots start to dry up.– Guard cells trigger when water is scarce causing

stomata to become flaccid and pores close.


Leaf Vein Types

Parallel Pinnate Palmate


Flowers (Reproduction)


Structure of Flowers


Petals– Highly colored part

of the flower, may contain perfume and/or nectar glands.

Sepals– Small green

structures on the base of a flower that protect the flower bud.

Image found at: http://biology.clc.uc.edu

Typical Flower Structure


Stamen contains:– Anther: produces pollen.– Filament: upholds anther.

Male Plant Organ


Pistil (carpels) contains:– Stigma: sticky for pollen to attach.– Style: sperm travel to ovary.– Ovary (fruit): stores ovules (eggs).

Female Plant Organ


Wind Water Animal

Seed Dispersal

Factors that affect seed germination: Temperature Moisture

Flower Pollination Animals Wind


Plant Response Plant hormones – chemical substances

that control a plant’s patterns of growth & development.

Target cell – cell that has a receptor for a particular hormone.


Tropisms (Response) Tropism – response of a plant to an

environmental stimulus.– Gravitotropism: response of a plant to the force of

gravity.– Phototropism: tendency of a plant to grow towards

light.– Thigmotropism: response of plants to touch.

Auxin – substance produced in the tip of the seedling that stimulates cell elongation.


Photoperiodism: the timing of seasonal activities such as flowering and growth.

Herbicides: auxinlike compounds in high concentrations that are toxic to plants therefore inhibiting growth.

Chemical defenses: many plants defend themselves against insect attack by manufacturing compounds that have powerful effects on animals, ex. poison oak.

sheryl searcy ninth grade center 2013 introducing plants section 22-1

Documents