Transcript Aquatic Multicellular Primary Producers

Exit Questions
1. List 4 characteristics of Aquatic Seaweeds.
2. Draw and label all five parts of a seaweed.
3. List one characteristic and one example of a
green algae.
4. List one characteristic and one example of
brown algae
5. List one characteristic and one example of a
red algae.
Aquatic
Multicellular
Primary
Producers
More commonly known as seaweeds and plants.
Seaweeds
• The most familiar types of marine algae
are most commonly known as seaweeds.
• More formal names include macrophytes
or macroalgae.
Seaweeds
• All are multicellular
and eukaryotic.
• The structures and
reproductive
methods are more
complex and
elaborate than
photosynthetic
unicellular
organisms.
General Structure
• Do not have roots,
stems, and leaves.
Thallus
• The complete body of the seaweed, no
matter what shape it takes.
Blades
• The leaf-like, flattened
portion of the thallus.
• Has large surface area
so most photosynthesis
occurs here.
• Have no veins.
• Upper and lower
surfaces are identical.
Pneumatocysts
• Gas-filled bladders that keep the blades
close to the sea surface – more
photosynthesis can take place here.
Stipe
• The distinct stemlike structure that
provides support.
• The blades
originate from
here.
Holdfast
• A root-like structure that attaches the
thallus to the bottom.
• Not involved in any significant absorption
of water or nutrients.
• Does not penetrate sand or mud.
Characteristics
• Seaweeds do not generally have tissues
that can be used for transporting water or
nutrients. Instead they use Diffusion and
Osmosis
•All of the organism is
found in water and can
photosynthesize, so
transporting these
materials isn’t
necessary.
Main Types of Seaweeds
• Three main types of seaweeds:
– Green, brown, and red algae
– Best identified by chemical analysis because
their natural color doesn’t always match their
name.
Green Algae
• Most is found in freshwater and on land.
• Only about 700 (10% of the total species)
are marine and most of these are
unicellular.
Green Algae
• Most have a very simple thallus.
• Pigments are similar to land plants.
•Chlorophyll is
not normally
masked by
other pigments
so green algae
are most often
bright green.
Green Algae
• Sea lettuce – found in all temperatures of
water
• Valonia – found in tropics and subtropics.
• Dead man’s fingers (Codium) – found in
tropical to temperate waters (North
America).
Brown Algae
• Colors can vary from olive green to dark
brown.
• Yellow-brown pigments (particularly
fucoxanthin) which masks the green
chlorophyll.
Brown Alage
• Almost all species are marine.
• Are often the dominant primary producers
on temperate and polar rocky coasts.
Brown Algae
• Include the Kelps:
the most complex
and largest of all
brown algae.
• Some kelp can be
as long as 100 m
and grow 50 cm
in one day.
Red Algae
• Very large group of organisms (more
species than green and brown algae
combined).
• Most are marine.
Red Alage
• Have red pigments called phycobilins.
• Live in most shallow water environments.
Red Algae
• Some are parasites of other algae while
others are heterotrophs and not able to
photosynthesize
Red Algae
• Gigantina – the most massive of the red
algae.
– Blades up to 2 m.
• Coralline algae deposit calcium carbonate
within the cell walls – aids in the formation
of coral reefs.