Download Embryo Sac

Flowers Laboratory
Flower Structure
and Interactions
with Pollinators
• Flowers are modified
leaves, specialized
for reproduction.
• Flowers form on the
diploid Sporophyte
• Flower parts
undergo meiosis to
produce haploid
Gametophytes
– pollen grain
– embryo sac
Flower
Sporophyte
Pollen
grains
embryo
sac
Gametophytes
Flowering Plant
Reproduction
Pistil
Stamen
A Complete Flower Has
Both Male and Female Parts
Anther
Filament
Stigma
Petal
Style
Sepal
Ovary
All Petals=Corolla
All Sepals=Calyx
Plant Reproduction
Flower Part
Function
Sepals
Enclose and protect bud
Petals
Attract pollinators
Stamen
Produce pollen in anther
Pistil (carpel)
Produce ovule in ovary
Mature
Sporophyte
Megaspore
meiosis
(female)
Microspore
(male)
Sperm
mitosis,
Cells mitosis,
differentiation,
differentiation
growth
mitosis,
Male
Gametophyte differentiation
Egg
(Pollen)
Cell
fusion
to form
zygote
in ovary
Female
Diploid
Gametophyte
2n
(Embryo Sac) Haploid
1n
Flowering
Plant
Life
Cycle
Mature Pollen
Grain
Sperm Cells
Tube Cell Nucleus
2. pollen tubes grow
down style to ovary
Sperm
1. pollen grains
land on stigma
Stigma
Style
3a Fusion of 2nd
sperm + two
polar nuclei
3. double
fertilization
3b Fusion of
sperm + egg
Ovule
Polar nuclei
Ovary
Egg
Pollination
and
Fertilization
in a Flower
Development of Fruit and Seeds
From Flower Parts
Endosperm
Triploid
Endosperm
Cell Fresh
Fruit
Ovary
Seed
Integument
Coat
Zygote
Embryo
Seed = fertilized ovule = embryo + endosperm + seed coat
Fruit = ovary wall, mechanism for seed dispersal
Comparing Monocot and Dicot Plants
Flower Symmetry
Radial
Symmetry
(Regular)
Bilateral
Symmetry
(Irregular)
Ovary Position
Superior
Ovary
Inferior
Ovary
Coevolution of Plant and Pollinator
Wind Pollination
Pollination by
Beetles
Pollination by
Ants
Pollination by
Carrion Flies
Pollination by Mammals
Pollination by
Wasps
Pollination
by Bees
Ultraviolet Patterns Guide Bees to Nectar
Human
Vision
Bee
Vision
Impersonating
a Pollinator
Pollination by
Moths
Pollination by
Hummingbirds
Pollination by
Butterflies
Composite
Flowers
CLEAN UP!
• Leave plant specimens in orderly arrays
• Discard dissected flower parts in the
trash
• Return any microscopes to their
cabinets
Thank you!
Worksheet
• Turn in pages 151-153 from lab manual
– Record your answer and reasoning for
any 10 specimens, making sure to write the
answer on the line that matches the
specimen number
• Be sure your instructor checks your
completed worksheet before you leave
the lab