11

Living organisms are classified Living organisms are classified into 3 Domainsinto 3 Domains

1.1. BacteriaBacteria

2.2. ArchaeaArchaea

3.3. EukaryaEukarya

4 Kingdoms in this Domain

22

Domain Eukarya has 4 Domain Eukarya has 4 KingdomsKingdoms

1. Kingdom Protista1. Kingdom Protista

2. Kingdom Fungi2. Kingdom Fungi

3. Kingdom 3. Kingdom PlantaePlantae

4. Kingdom Animalia4. Kingdom Animalia

33

Characteristics of Characteristics of PlantsPlants

EukaryotesEukaryotes MulticellularMulticellular Can not moveCan not move Autotrophic-can Autotrophic-can

PhotosynthesizePhotosynthesize Thick cell walls made of Thick cell walls made of

cellulosecellulose

44

Adaptations of PlantsAdaptations of Plants

Cuticle to prevent water lossCuticle to prevent water loss Leaves for carrying out photosynthesisLeaves for carrying out photosynthesis Roots to anchor and absorb water and Roots to anchor and absorb water and

mineralsminerals Stems for support and transport of food, water Stems for support and transport of food, water

and mineralsand minerals Vascular tissues for transport in some plantsVascular tissues for transport in some plants Most have seeds for reproductionMost have seeds for reproduction Alternation of generationsAlternation of generations

55

Plant EvolutionPlant Evolution

Plants are divided into vascular and Plants are divided into vascular and nonvascularnonvascular

The Vascular plants are divided into The Vascular plants are divided into seed plants and non seed plantsseed plants and non seed plants

The Seed Plants are divided into those The Seed Plants are divided into those with cones and those with flowerswith cones and those with flowers

66

Vascular/NonvascularVascular/NonvascularSeed/SeedlessSeed/Seedless

BryophytesBryophytes are the non vascular are the non vascular plants with focus on the mossplants with focus on the moss

The The PterophytesPterophytes are the ferns and are the ferns and they are vascular and seedlessthey are vascular and seedless

The Seed plants consist of the The Seed plants consist of the GymnospermsGymnosperms with cones and the with cones and the AngiospermsAngiosperms with flowers. with flowers.

77

GinkgophytaGinkgophyta

A division of seed plants that A division of seed plants that

have only have only one living speciesone living species The leaves of the plant are The leaves of the plant are fan shapedfan shaped For centuries it was thought to be For centuries it was thought to be

extinct in the wild, but is now known to extinct in the wild, but is now known to grow wild in eastern grow wild in eastern ChinaChina. The wild . The wild status of ginkgos there is uncertain. status of ginkgos there is uncertain.

88

Evolution of PlantsEvolution of Plants

4 major evolutionary steps

99

Alternation of Generations Alternation of Generations Gametophyte and SporophyteGametophyte and Sporophyte

Notice that the more advanced

plants have a dominant

Sporophyte and the less

advanced plants have a

more dominant

Gametophyte

1010

Moss Life CycleMoss Life Cyclehttp://intro.bio.umb.edu/111-112/112s99Lect/life-cycles.htmlhttp://intro.bio.umb.edu/111-112/112s99Lect/life-cycles.html

http://www.sumanasinc.com/webcontent/anisamples/majorsbiology/moss.htmlhttp://www.sumanasinc.com/webcontent/anisamples/majorsbiology/moss.html

Moss Life Cycle

1111

Fern Life CycleFern Life Cyclehttp://intro.bio.umb.edu/111-112/112s99Lect/life-cycles.htmlhttp://intro.bio.umb.edu/111-112/112s99Lect/life-cycles.html

1212

Alternation of GenerationsAlternation of Generations

By definition, all plants alternate

generations

Gametophyte

n=haploid

Sporophyte 2n=diploid

1313

Vascular TissueVascular TissueXylem

specialized cells for carrying water and dissolved minerals from the

roots

The specialized cells found in Xylem are the tracheids

Phloem

cells for carrying food produced in the leaves through photosynthesis

to all parts of the plant

Vascular CambiumThe specialized tissue that gives rise to

new Xylem and Phloem

This is the tissue that brings about the growth of a tree trunk

1414

Leaf StructureLeaf Structurehttp://www.purchon.com/biology/flash/leaf.swfhttp://www.purchon.com/biology/flash/leaf.swf

•The primary function of leaves is photosynthesis•Most photosynthesis takes place in the Palisade mesophyll•Spongy mesophyll is loosely packed cells and permits gases to move between palisade cells and the outside of the leaf

1515

Root StructureRoot Structure

•Apical Mesistems are found at the tips of roots•This is an area of active growth•There are also meristems found at the tips of growing stems

1616

Root FunctionsRoot Functions

Anchor plantsAnchor plants Absorb water and minerals Absorb water and minerals May store carbohydrates (carrots, potatoes, May store carbohydrates (carrots, potatoes,

turnips)turnips) May store water for dry periodsMay store water for dry periods Plant Cells use minerals, such as nitrogen Plant Cells use minerals, such as nitrogen

and potassium in LARGE amounts; called and potassium in LARGE amounts; called macronutrients macronutrients 

Minerals needed in SMALL amounts are Minerals needed in SMALL amounts are called micronutrientscalled micronutrients

Mineral deficiencies or excess minerals can Mineral deficiencies or excess minerals can kill plantskill plants

1717

Transport in PlantsTransport in Plants

•Transport in a plant involves movement of water, minerals, macro and micronutrients by vascular cambium•Xylem transports water and minerals from the roots•Phloem transports food from the leaves to all parts of the plant •Root Hairs aid in the absorption of water and minerals because it increases the surface area of roots

1818

Structure and Function of Structure and Function of StomataStomata

If water enters the guard cells, they swell up and If water enters the guard cells, they swell up and the stomata opensthe stomata opens

If water leaves the guard cells, they become If water leaves the guard cells, they become flaccid and the stomata closesflaccid and the stomata closes

1919

Angiosperm or Flowering Plant Angiosperm or Flowering Plant ReproductionReproduction

The Sporophyt

e is the dominant

stage in the life cycle of

the Angiosperm

s

2020

Basic Flower Structure of an Basic Flower Structure of an Angiosperm Angiosperm

http://plantandsoil.unl.edu/croptechnology2005/plant_phys/?what=animationList&informationModuleId=http://plantandsoil.unl.edu/croptechnology2005/plant_phys/?what=animationList&informationModuleId=10872300401087230040

•Sepals protect the flower bud from insect damage and dryness•The color, scent, and nectar of flowers attracts insects, bats, and birds•These animals help to transfer the pollen from the anthers of one flower to the stigma of other flowers-called pollination

2121

Complete and Incomplete Complete and Incomplete FlowersFlowers

Perfect Flowers: have Perfect Flowers: have both male and female both male and female reproductive structures.reproductive structures.

Imperfect Flowers: have Imperfect Flowers: have either male or female either male or female structuresstructures

Complete flowers:Complete flowers: have have four basic structures: four basic structures: petals, petals, sepals, a stamen and a sepals, a stamen and a pistilpistil

Incomplete flowers:Incomplete flowers: have have one or more of these one or more of these structures lackingstructures lacking

2222

Pollen Tube Growth and Pollen Tube Growth and Fertilization in AngiospermsFertilization in Angiosperms

•The Pollen grains are transferred to the Stigma where the pollen grain produces a Pollen tube•The pollen tube grows down the style into the ovary where it fuses its nuclei with the nuclei of the ovule•The fertilized ovule becomes a seed and the ovary develops into the fruit of the plant

2323

Plant ResponsesPlant Responses

Example: Sensitivity to pressure or touch

This can be protective for the plant

2424

PhototropismPhototropism

Positive Positive Phototropism: Phototropism: the plant is the plant is bending bending toward the toward the sunlightsunlight

2525

PhototropismPhototropism

PhototropismPhototropism is illustrated by the is illustrated by the movement of plants in relation to light movement of plants in relation to light source directionsource direction

Light causes the hormone Light causes the hormone auxinauxin to move to move to the shaded sideto the shaded side

The The auxinauxin causes the cells on the shaded causes the cells on the shaded side to elongateside to elongate

As a result, the shoot bends toward the As a result, the shoot bends toward the light and exhibits light and exhibits positive phototropismpositive phototropism

2626

ThigmotropismThigmotropism

Thigmotropism is a plant growth response to Thigmotropism is a plant growth response to touching a solid objecttouching a solid object

Tendrils and stems of vines, such as morning glories, Tendrils and stems of vines, such as morning glories, coil when they touch an object coil when they touch an object

Thigmotropism allows some vines to climb other Thigmotropism allows some vines to climb other plants or objects, thus increasing its chance of plants or objects, thus increasing its chance of intercepting light for photosynthesis.intercepting light for photosynthesis.

2727

Geotropism or GravitropismGeotropism or Gravitropism

2828

GravitropismGravitropism

GravitropismGravitropism is a plant growth is a plant growth response to gravity response to gravity

A root usually grows downward A root usually grows downward and a stem usually grows upwardand a stem usually grows upward

RootsRoots are are positively positively gravitropicgravitropic and and stemsstems are are negatively gravitropicnegatively gravitropic

2929

Plant HormonesPlant Hormones

AuxinAuxin-This hormone promotes cell -This hormone promotes cell elongationelongation

Auxin is found in the apical meristems Auxin is found in the apical meristems of plantsof plants

GibberellinsGibberellins help the plants to grow help the plants to grow tallertaller

Gibberellins Gibberellins also increase the rate of also increase the rate of seed germinationseed germination and and bud bud developmentdevelopment

3030

Angiosperms are Divided intoAngiosperms are Divided intoMonocots and DicotsMonocots and Dicots

3131

Monocots and Dicots AgainMonocots and Dicots Again

3232

Monocot and Dicot Seed Monocot and Dicot Seed StructureStructure

3333

Monocot and Dicot Leaf Monocot and Dicot Leaf VeinsVeins

3434

Monocot and Dicot Flower Monocot and Dicot Flower PedalsPedals

MonocotMonocot-pedals in groups of three -pedals in groups of three or multiplesor multiples

DicotsDicots-pedals in groups of 4s or 5s-pedals in groups of 4s or 5s

3535

Monocot and Dicot StemMonocot and Dicot Stem MonocotsMonocots-vascular tissue scattered-vascular tissue scattered DicotsDicots-vascular tissue around edge of stem-vascular tissue around edge of stem

3636

Examples of Monocots and Examples of Monocots and DicotsDicots

Monocots include: Monocots include: grasses, grasses, oats, wheat, orchids, lilies oats, wheat, orchids, lilies and palmsand palms

Dicots include: Dicots include: shrubs, trees shrubs, trees (except conifers) wild (except conifers) wild flowers and some garden flowers and some garden flowersflowers

3737

Monocot and Dicot Seed Monocot and Dicot Seed AnatomyAnatomy Food is stored in Food is stored in

the the cotyledoncotyledon for for the embryothe embryo

The The seed coatseed coat functions as a functions as a physical barrierphysical barrier

EpicotylsEpicotyls becomes becomes the leaves of plantthe leaves of plant

Hypocotyls Hypocotyls becomes the stembecomes the stem

RadicleRadicle becomes becomes the rootthe root

3838

Seed GerminationSeed Germination

Requirements for seed germination include:•Enough water to activate the metabolism of embryo•Sufficient oxygen for respiration•Suitable temperature for growth of that species

3939

Seed DispersalSeed Dispersal

Seeds dispersal is Seeds dispersal is completed by birds, completed by birds, small animals, wind, small animals, wind, and waterand water

The tough, fibrous The tough, fibrous outer covering of a outer covering of a coconut provides coconut provides protection as well as protection as well as a floatation devicea floatation device

4040

Seed GerminationSeed GerminationSeeds are stored food with an Seeds are stored food with an

EmbryoEmbryoSome species need unusual conditions

for Germination: Pass through acidic environment of

an animals digestive system Some require freezing temperatures,

extensive soaking in water (rice), exposure to fire (conifers/pines), or certain day lengths

4141

Genetic Engineering of Genetic Engineering of PlantsPlants

Plants can be genetically engineered Plants can be genetically engineered to: to: Be more Be more toleranttolerant of different of different

climates & soilsclimates & soils Produce Produce more fruitmore fruit Be more Be more nutritiousnutritious Be more resistant to Be more resistant to insectsinsects

and and herbicidesherbicides