Sexual Reproduction in Flowering Plants
Visit: http://koning.ecsu.ctstateu.edu/Plants_Human/lecppt/flower.ppt
Alternation of Generations in Plants
Life Cycle of a Typical Animal
Life Cycle of a Typical Plant
Flowers and Fossils
The Rise and Fall of Dinosaurs
• Dinosaurs are found in the
fossil record starting about
230 million years ago.
• The last dinosaurs bcame
extinct about 65 million
years ago.
• Impact Hypothesis: A
10km-wide meteorite had
smashed into the Yucatan
peninsula in Mexico,
causing worldwide forest
fires, tsunamis several
kilometres high, and an
'impact winter'
The Rise and Fall of Dinosaurs
• Evidence prior to impact
that diversity of dinosaur
species was on the
decline.
• Climate change?
• Rise of Angiosperms?
– Sometime in the MidCretaceous Period; between
144 to 65 Million Years
Ago
– Corresponds with a decline
of the gymnosperms and
rise of animal groups
Why Dinosaurs Went Extinct!
The Far Side by Gary Larson.
Basic Flower Structure
stigma
locule
carpel
gynoecium
style
ovule
pollen
ovary
Flower is perfect
Flower is monoecious
anther
filament
stamen
androecium
petal
corolla
receptacle
pedicel
sepal
calyx
perianth
Perianth is complete
Some Example Stories:
Perfect Flowers: Pea exclusively self-pollinating
Hibiscus self-pollinating if not crossed
Cherry self-incompatible only outcrosses
Imperfect Flowers: Begonia unisexual but monoecious
Holly unisexual and dioecious
Variable: Cucumber male, perfect, female, parthenocarpic
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
Ovary Superior
Flower Hypogynous
Ovary Half-Superior
Flower Perigynous
Ovary Half-Inferior
Flower Epigynous
Ovary Inferior
Flower Structure - review
Ranunculus acris - buttercup
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 Formula: Symbol Sequence to Diagram Flower
Symmetry: *=radial †=bilateral
* 5, 5, , 5
Number of Parts per Whorl:
• sepals in calyx
• petals in corolla
• stamens in androecium
• carpels in gynoecium
Fusion within whorl:
curved line over number
Fusion between whorls:
square bracket below numbers
Attachment of flower parts relative to ovary:
horizontal line
Ovary Superior
Flower Hypogynous
Ovary Half-Superior
1
Flower Perigynous
Ovary Half-Inferior
Flower Epigynous
Ovary Inferior
1
1