Transcript flowering plants

PLANTS
• eukaryotic
• autotrophic (through
photosynthesis)
• cells have walls made
of cellulose
• Animals are
diploid individuals
with only haploid
stages in sperm
and egg.
• Plants alternate
between a haploid
and a diploid
generation.
• Diploid (2n) =
sporophyte;
haploid (n) =
gametophyte.
ALTERNATION of
GENERATIONS
HIGHLIGHTS OF PLANT
EVOLUTION
Four key adaptations to
life on land
1. Dependent embryos, which are nourished and
protected on the parent plant.
2. Vascular tissues (xylem and phloem) transport
water, nutrients and provides support for
upright stems found in most modern plants..
3. Seed producers appeared and these plants
dominate the plant kingdom today.
4. Flowers provide a new process for plant
reproduction.
Evolution of Plants
Transport
Non-vascular
(live in water)
Vascular
(true land
plants)
Phylum
Algae
Examples
Bryophytes
Seaweed (unicellular,
colonial, & multicellular)
Moss, liverworts
Pteridophytes
Ferns, horsetails
Gymnosperms
Evergreen trees
Angiosperms
Flowering plants
Unicellular Algae
Euglena & Diatoms
– protists or plants?
Chlamydomonas (right) unicellular.
- moves using flagella.
Volvox
– lives in colonies. Some
cells are specialized!
Unicellular to Multicellular Plants
• Unicellular-all of life’s activities occurs
within a single cell.
• Colonial – Some cell specialization
distributes jobs.
• Multicellular-various
specialized
cells,
which perform different functions and are
interdependent.
Spirogyra
– multi-cellular
- cells are stacked
end to end.
- specialization of
some cells.
Ulva (sea lettuce)
– multi-cellular
- releases gametes
for reproduction.
Green Algae Brown Algae
Chlorophyll
A & B
Chlorophyll
A & C
Red Algae
Chlorophyll
A & D
Blade
- thin for diffusion of
nutrients & gas
- photosynthetic
- may secrete mucous
Float (air bladder)
– brings algae closer to
surface and sunlight
Stipe
- photosynthetic extension
Holdfast
- anchors algae
Algal
Structure
Kelp Forests
Provide habitat
for numerous
organisms and
minimize the
pounding
effects of
waves.
Challenges
of moving
to land!
- Drying out
- transport of
nutrients.
- Reproduction
(sperm moving
to egg)
Bryophytes
(moss, liverworts, & hornworts)
Bryophytes
Can survive on land but are heavily dependant on
water.This is why they like shady areas.
•
•
•
•
Depend on diffusion for transport
Are thin and dry out easily
Sperm need to swim to the egg
Have rhizoids instead of true roots
Moss have a dominant haploid
gametophyte generation
Life cycle of a moss
Pteridophytes
(ferns)
Pteridophytes
• Have true roots and vascular tissue for
transport up stem.
• Have a waxy cuticle on fronds (leaves)
to prevent drying out.
• Sperm do still need water to swim to the
egg on the prothallus
Ferns have a dominant diploid
sporophyte generation
Life cycle of a fern
Gymnosperms
(evergreens)
• Have cones for reproductive structures.
• Rely on wind for pollen dispersal from
the smaller male cone to the larger
female cone.
• Produce exposed (“naked”) seeds on
their cones.
• Have tough needles which withstand
cold climates.
Gymnosperm Lifecycle
Single
fertilization
Angiosperms
(flowering plants)
• Have flowers for reproductive
structures.
• Use wind and animals for pollen
dispersal
• Produce protected seeds that
contain food for their embryo.
• Have broad flat leaves.
Plant Porn???
Plant Peep
Show
Angiosperm Lifecycle
Double
fertilization
Flower Diversity