Flowers Laboratory Flowers Laboratory

Flower Structure Flower Structure and Interactionsand Interactions

with Pollinatorswith Pollinators

Flowering Plant Flowering Plant ReproductionReproduction

• Flowers are modified Flowers are modified leaves, specialized leaves, specialized for reproduction.for reproduction.

• Flowers form on the Flowers form on the diploid diploid SporophyteSporophyte

• Flower parts Flower parts undergo meiosis to undergo meiosis to produce haploid produce haploid GametophytesGametophytes– pollen grainpollen grain– embryo sac embryo sac

Pollengrains

embryosac

Flower Sporophyte

Ga

met

op

hyt

es

A Complete Flower Has A Complete Flower Has

Both Male and Female PartsBoth Male and Female Parts

SepalSepal

PetalPetal

OvaryOvary

StyleStyle

StigmaStigma

Pist

ilPi

stil

Pist

ilPi

stil

AntherAntherFilamentFilament

Stam

enSt

amen

Stam

enSt

amen

All Sepals=CalyxAll Sepals=Calyx

All Petals=CorollaAll Petals=Corolla

Plant ReproductionPlant Reproduction

Flower PartFlower Part FunctionFunction

SepalsSepals Enclose and protect budEnclose and protect bud

PetalsPetals Attract pollinatorsAttract pollinators

StamenStamen Produce pollen in antherProduce pollen in anther

Pistil (carpel)Pistil (carpel) Produce ovule in ovaryProduce ovule in ovary

Flowering Flowering Plant Plant Life Life CycleCycle

HaploidHaploid1n1n

DiploidDiploid2n2n

MatureMatureSporophyteSporophyte

meiosismeiosisMegasporeMegaspore(female)(female)

MicrosporeMicrospore(male)(male)

mitosis,mitosis,differentiationdifferentiation

mitosis,mitosis,differentiationdifferentiation

MaleMaleGametophyteGametophyte(Pollen)(Pollen)

SpermSpermCellsCells

FemaleFemaleGametophyteGametophyte(Embryo Sac)(Embryo Sac)

EggEggCellCell

fusionfusionto formto formzygotezygote

in ovaryin ovary

mitosis,mitosis,differentiation,differentiation,growthgrowth

Mature PollenMature PollenGrainGrain

Pollination Pollination andandFertilization Fertilization in a Flowerin a Flower

Tube Cell NucleusTube Cell NucleusSperm CellsSperm Cells

1.1. pollen grainspollen grainsland on stigmaland on stigma

StigmaStigma

StyleStyle

OvaryOvary

2.2. pollen tubes growpollen tubes growdown style to ovarydown style to ovary

SpermSperm

EggEgg

3b3b Fusion ofFusion ofsperm + eggsperm + egg

3a3a Fusion of 2Fusion of 2ndnd

sperm + twosperm + twopolar nucleipolar nuclei

3.3. doubledoublefertilizatiofertilizationn

Polar nucleiPolar nuclei

OvuleOvule

Development of Fruit and SeedsFrom Flower Parts

TriploidTriploidEndospermEndosperm

CellCell

TriploidTriploidEndospermEndosperm

CellCell

OvaryOvaryOvaryOvaryIntegumentIntegumentIntegumentIntegument

ZygoteZygoteZygoteZygote

EndospermEndospermEndospermEndosperm

FreshFreshFruitFruitFreshFreshFruitFruit

SeedSeedCoatCoatSeedSeedCoatCoat

EmbryoEmbryoEmbryoEmbryoSeed = fertilized ovule = embryo + endosperm + seed coatFruit = ovary wall, mechanism for seed dispersal

Comparing Monocot and Dicot Plants

Flower SymmetryFlower Symmetry

RadialRadial Symmetry Symmetry(Regular)(Regular)

Bilateral Bilateral SymmetrySymmetry(Irregular)(Irregular)

Ovary PositionOvary Position

Superior Ovary

InferiorOvary

Coevolution of Plant and PollinatorCoevolution of Plant and Pollinator

Wind PollinationWind Pollination

Pollination by Pollination by BeetlesBeetles

Pollination by Pollination by AntsAnts

Pollination by Pollination by Carrion FliesCarrion Flies

Pollination by MammalsPollination by Mammals

Pollination by Pollination by WaspsWasps

PollinationPollination by Bees by Bees

Ultraviolet Patterns Guide Bees to NectarUltraviolet Patterns Guide Bees to Nectar

HumanHumanVisionVision

BeeBeeVisionVision

Impersonating Impersonating a Pollinatora Pollinator

Pollination by Pollination by MothsMoths

Pollination by Pollination by HummingbirdsHummingbirds

Pollination by Pollination by ButterfliesButterflies

Composite Composite FlowersFlowers

CLEAN UP!CLEAN UP!

• Leave plant specimens in orderly arraysLeave plant specimens in orderly arrays• Discard dissected flower parts in the Discard dissected flower parts in the

trashtrash• Return any microscopes to their Return any microscopes to their

cabinets cabinets

Thank you!Thank you!

WorksheetWorksheet

• Turn in pages 155-157 from lab manualTurn in pages 155-157 from lab manual– Record your answer and reasoning for Record your answer and reasoning for

any 10 any 10 specimens, making sure to write the specimens, making sure to write the answer on the line that matches the answer on the line that matches the specimen numberspecimen number

• Be sure your instructor checks your Be sure your instructor checks your completed worksheet before you leave completed worksheet before you leave the labthe lab