Transcript Pollen & Embryo Sac Slides

Basic Flower Structure
stigma
Pistil is simple
locule
carpel
gynoecium
style
ovule
pollen
ovary
superior
Flower is perfect
Flower is monoecious
anther
filament
Flower is hypogynous
stamen
androecium
petal
corolla
receptacle
pedicel
sepal
calyx
perianth
Perianth is complete
This longitudinal section view does not
allow us to consider symmetry
Flower Functions Leading to Sex
pollination
vectors: animals, wind
pollen tube growth
pollen dehiscence
x
syngamy
chemotropism
What are the rest of the flower parts doing?
Anther Cross Section - How many anther sacs are present?
epidermis
vein
mesophyll
pollen grains
Pollen grain
Tube Cell
cytoplasm
nucleus
nucleolus
Digests path
through
stigma, style,
and ovary.
Locates
micropyle of
ovule.
Pollen Wall
Penetrates
Waterproofing prevents desiccation during
into embryo pollen transfer. Recognition proteins cause
sac.
allergic reactions.
Generative
Cell
cytoplasm
nucleus
nucleolus
Divides by
mitosis to
make two
sperm.
Both join
in
syngamy
events.
VIP: Pollen Grain
Pollen Wall
Tube
Cell
Generative
Cell
Cytoplasm
Cytoplasm
Nucleus
Nucleus
Nucleolus
Nucleolus
Fate:
Digests Path to Egg
Locates Micropyle
Enters Embryo Sac
Is Burst to Release Sperm
Fate:
Follows Path of Tube
Divides by Mitosis
Makes Two Sperm
Both Have Syngamy
Pollen grain deposited by vector on stigma
Tube cell germinates through pollen wall
generative
nucleus
pollen
tube
tube
nucleus
Pollen tube digests pathway to egg
Attracted to source of hormones, Calcium, Boron
Chemotropism toward micropyle of ovule
Penetrates into embryo sac
Generative cell follows pathway of pollen tube.
Generative cell divides to make two sperm cells.
tube
nucleus
Golgi
and
vesicles
Synergids burst end of pollen tube.
Sperm released into embryo sac.
Syngamy events follow.
Rhododendron maximum ovule ls
Integument
3 Antipodal Cells
disintegrate
Central Cell
+ sperm = endosperm
Egg Cell
+ sperm = zygote
2 Synergid Cells
burst pollen tube
release sperm
disintegrate
Micropyle of Integument
Embryo
Sac
VIP: Embryo Sac in Ovule
Ovule
Embryo
Sac
Integument
Antipodals
Funiculus
Micropyle
Central Cell
Egg
Synergids
Plant Pornography?
Disintegrating Antipodals
Central Cell
Polar Nuclei
Sperm Nucleus
Syngamy Product = Endosperm 3N
Egg Cell
Sperm Nucleus
Egg Nucleus
Syngamy Product = Zygote 2N
Disintegrating Synergids
After Syngamy, the Names are Changed…
• Egg becomes Zygote
• Central cell becomes Endosperm
• Ovule becomes Seed
• Integument becomes Seed coat
• Ovary wall becomes Fruit
Capsella shepherd’s purse seed
Integument became seed coat
Egg became zygote
Zygote became embryo
Central Cell became endosperm
Ovary became fruit