Chapter 25Chapter 25PlantsPlants

Brandon Kraft, Brandon Kraft,

Carly Miller, Carly Miller,

and Nick Regoand Nick Rego

Evolutionary Trends Evolutionary Trends Among PlantsAmong Plants

Photoautotrophs-organisms Photoautotrophs-organisms

that get energy from sun that get energy from sun

and COand CO22

Vascular plantsVascular plants Account for most plantsAccount for most plants

Roots, stems, leavesRoots, stems, leaves

Three TypesThree Types Seedless Vascular Plants Seedless Vascular Plants

Cycads, lycophytes, fernsCycads, lycophytes, ferns

Seed-Bearing Vascular PlantsSeed-Bearing Vascular Plants GymnospermsGymnosperms

AngiospermsAngiosperms

Non-vascular plantsNon-vascular plants Account for remainder Account for remainder

of plantsof plants

BryophytesBryophytes

LiverwortsLiverworts

HornwortsHornworts

MossesMosses

Evolution of Roots, Evolution of Roots, Stems, and LeavesStems, and Leaves

RootsRoots Evolved for life on landEvolved for life on land

Underground, absorbtiveUnderground, absorbtive

Shoot systemsShoot systems Stems and leavesStems and leaves

Above GroundAbove Ground

Absorb Sunlight and Absorb Sunlight and

COCO22

Support of cell wallSupport of cell wall

Evolved LigninEvolved Lignin

Vascular tissue- for Vascular tissue- for

transport of materialstransport of materials XylemXylem

PhloemPhloem

Water conservation- Water conservation-

necessary because of air necessary because of air

exposure (prevents exposure (prevents

dehydrationdehydration CuticleCuticle

StomataStomata

Evolution of Pollen and SeedsEvolution of Pollen and Seeds

HeterosporyHeterospory Produce two types of sporesProduce two types of spores

Sperm-bearing gametophytesSperm-bearing gametophytes Female gametophytesFemale gametophytes

Spread by air, insects, birdsSpread by air, insects, birds

Seeds - contain embryo and sustinenceSeeds - contain embryo and sustinence

BryophytesBryophytes

Mosses(most common), liverworts, hornworts (nonvascular)Mosses(most common), liverworts, hornworts (nonvascular)

3 adaptive features:3 adaptive features:

1. Above ground parts display a cuticle with numerous stomata1. Above ground parts display a cuticle with numerous stomata

2. Cellular protective jacket surrounds the sperm-producing 2. Cellular protective jacket surrounds the sperm-producing

and egg-producing parts of the plant to prevent dryingand egg-producing parts of the plant to prevent drying

3. The embryo sporophyte begins life inside the female 3. The embryo sporophyte begins life inside the female

gametophytegametophyte

Branched, feathery patternsBranched, feathery patterns

Reproduce w/ flagellated sperm, which require liquid water to Reproduce w/ flagellated sperm, which require liquid water to

reach and fertilize the eggsreach and fertilize the eggs

Moss Life CycleMoss Life Cycle

Existing Seedless Existing Seedless Vascular PlantsVascular Plants

Whisk ferns, Lycophytes, Horsetails, FernsWhisk ferns, Lycophytes, Horsetails, Ferns 3 Differences from Bryophytes3 Differences from Bryophytes

Sporophyte not attached to a gametophyteSporophyte not attached to a gametophyte Has vascular tissuesHas vascular tissues Longer phase in life cycleLonger phase in life cycle

Habitat Habitat Moist placesMoist places

Gametophytes lack vascular tissueGametophytes lack vascular tissue Sperm needs water to reach eggSperm needs water to reach egg

Life Cycle of a FernLife Cycle of a Fern

The Rise of the The Rise of the Seed-Bearing PlantsSeed-Bearing Plants

*360 million years ago*360 million years ago

3 differences from seedless vascular plants3 differences from seedless vascular plants 1. Produce pollen grains-the sperm-bearing male gametophytes1. Produce pollen grains-the sperm-bearing male gametophytes

MicrosporesMicrospores give rise to pollen grains give rise to pollen grains

Does not depend on Does not depend on HH2200

2. Also produce 2. Also produce megasporesmegaspores, which develop inside , which develop inside ovulesovules-at -at

maturity is a seed (consist of female gametophyte)maturity is a seed (consist of female gametophyte)

3. Have H3. Have H220 conserving traits0 conserving traits

Thicker cuticlesThicker cuticles

Stomata recessed below the leaf surfaceStomata recessed below the leaf surface..

Spore of A LycophyteSpore of A Lycophyte

Seed-Bearing PlantsSeed-Bearing Plants

Depend onDepend on

Pollen grainsPollen grains

Ovules that mature Ovules that mature

into seedsinto seeds

Tissue changes Tissue changes

adapted to dry adapted to dry

conditionsconditions

Gymnosperms- Gymnosperms- Plants with “Naked” SeedsPlants with “Naked” Seeds

Have exposed seeds-Have exposed seeds- gymnos means “naked,” sperma means “seed”gymnos means “naked,” sperma means “seed” Conifers - have conesConifers - have cones

Woody trees/shrubs with needlelike leavesWoody trees/shrubs with needlelike leaves ConesCones- clusters of modified leaves that surround the spore-producing structures- clusters of modified leaves that surround the spore-producing structures Firs, yews, spruces, junipers, larches, cypresses, etc.Firs, yews, spruces, junipers, larches, cypresses, etc.

Lesser Known GymnospermsLesser Known Gymnosperms

Cycads-Cycads-have pollen-bearing and seed have pollen-bearing and seed

bearing cones that form on separate bearing cones that form on separate plantsplants

Tropical/Subtropical areasTropical/Subtropical areas Largest seed-bearing conesLargest seed-bearing cones Many vulnerable to Many vulnerable to

extinctionextinction

GingkoGingko Gingko bilobaGingko biloba - only survivor - only survivor Diverse in dinosaur timesDiverse in dinosaur times Males are resistant to insects, Males are resistant to insects,

disease, and air pollutantsdisease, and air pollutants

Gnetophytes-Gnetophytes-woody plants that woody plants that

have 3 typeshave 3 types

Tropics and arid areasTropics and arid areas

**Groups of existing **Groups of existing

gymnosperms include conifers, gymnosperms include conifers,

cycads, ginkgos, and cycads, ginkgos, and

gnetophytes, which bear their gnetophytes, which bear their

seeds on exposed surfaces of seeds on exposed surfaces of

cones and other spore-cones and other spore-

producing structuresproducing structures..

ConifersConifers Gymnosperms that Gymnosperms that

reproduce via Cone reproduce via Cone Structures (Pinecones)Structures (Pinecones)

Conifers produce both male Conifers produce both male and female pineconesand female pinecones Male Pinecones Male Pinecones

Produce Microspores (Pollen Produce Microspores (Pollen grains) that drift into the airgrains) that drift into the air

Female PineconesFemale Pinecones Produce Megaspores Produce Megaspores

(Female Gametophtes)(Female Gametophtes) Accept Pollen grainsAccept Pollen grains Pollen Grows into OvulePollen Grows into Ovule Fertilization Occurs Fertilization Occurs

months after pollinationmonths after pollination

Slow Reproductive RateSlow Reproductive Rate DisadvantageDisadvantage Angiosperms reproduce Angiosperms reproduce

faster and compete for faster and compete for resourcesresources

DeforestationDeforestation Vulnerable Vulnerable

AngiospermsAngiospermsThe Flowering Seed-Bearing PlantsThe Flowering Seed-Bearing Plants

Most Successful PlantsMost Successful Plants

Only plants that flowerOnly plants that flower Angeion- Female Angeion- Female

reproductive part of flowerreproductive part of flower

Requires pollinationRequires pollination Transfer of pollen from Transfer of pollen from

one plant to nextone plant to next

Pollination ProcessesPollination Processes Airborne pollenAirborne pollen

PollinatorsPollinators Insects, bats, birdsInsects, bats, birds

CoevolutionCoevolution

Angiosperm diagram:

Dicots and MonocotsDicots and Monocots

Two Types Two Types Monocots and DicotsMonocots and Dicots

MonocotsMonocots Monocotyledon-Monocotyledon-

One cotyledon (seed leaf for storage of food) in seedsOne cotyledon (seed leaf for storage of food) in seeds

Floral parts in groups of threesFloral parts in groups of threes

Parallel veins in leavesParallel veins in leaves Orchids, palms, lilies, grasses (most crops-wheat, corn, etc)Orchids, palms, lilies, grasses (most crops-wheat, corn, etc)

DicotsDicots

Dicotyledon-Dicotyledon- Two cotyledons in seedsTwo cotyledons in seeds

Floral parts in groups of four or fiveFloral parts in groups of four or five

Net-veined leavesNet-veined leaves Most Herbaceous (non-wooden) plantsMost Herbaceous (non-wooden) plants

Most flowering shrubs and treesMost flowering shrubs and trees

Water Lilies, CactiWater Lilies, Cacti