Biology 110
Algal diversity
Characteristics of Algae:
- Eukariotic (endosymbiotic origin)
- Aquatic (fresh water and salt water)
- Photosynthetic autotrophs (Chlorophyll a + various
photosynthetic accessory pigments).
- Cell walls (various components that can be useful for
classifying different groups).
Life as an aquatic photosynthetic autotroph:
- Source of energy?
- Depth in water column affects: light availability (no light
below 300 m depth) and spectral composition (red wavelengths
strongly absorbed by water)
- Assimilation of dissolved inorganic molecules of carbon and
mineral nutrients.
- Supported by water.
Diversity and importance:
- Microalgae - phytoplankton
- Macroalgae - seaweeds - body (thallus) plan: holdfast, stipe,
blades
Sexual life histories are quite varied even within major taxonomic
divisions.
Distinguish between major groups in terms of body plan, habitat,
accessory pigments, cell wall composition and importance to humans.
- Dinoflagellates
- Diatoms
- Brown algae (Phaeophyta)
- Red algae (Rhodophyta)
- Green algae (Chlorophyta)