3. • Holdfast – serves as an
anchor to help hold the
algae to the bottom, a rock,
etc.
• Blade – a place where
photosynthesis can occur;
there’s a wide variety of
shapes and sizes of blades
• Stipe – provides support
and structure for the algae
• Air Bladder (aka Float) – a
structure that assists in
buoyancy for the algae
(why?)
• Thallus – the entire body
structure of the seaweed
4. Kingdom=? Protista, Plantae, Other?
• Autotrophs
• Live attached to rocks or floating
• Reproduction is usually sexual, frequently through
spores
• Huge diversity, found nearly everywhere on earth
• 3 types
5. A) Green – Chlorophytes
•
•
•
•
Least common; need lots of light
Possibly land plants evolved from this type of algae
Deep to bright green due to chlorophyll
Ex: Sea lettuce, Mermaid’s Hair
6. B) Red - Rhodophytes
•
•
•
•
Common; can handle low light (found deepest)
Contain pigments (phycoerythryn, phycocyanin)
Don’t always look red!
Examples: Gracillaria, Nori
7. C) Brown - Phaeophytes
• Common in cold water, rocky shores to 60’ deep
• Olive color due to pigment xanthophyll
• Examples: Ascophyllum (rockweed), Kelp
8. Comparisons Between Algae & Land Plants
-Water usually
unlimited
-Supported by
stipes
-Anchored by
holdfast
-No seeds &
flowers
-Blades
Autotrophs –
perform
photosynthesis
-Water usually
limited
-Supported by
trunks & stems
-Anchored by
roots
-Flowers & seeds
-Leaves
