### microalgae:

Green algae
* All green algae are microscopic but some forms organize themselves into visible colonies
  - have mitochondria with flat cristae
* Many green algae have an alternation of haploid and diploid phases.
* Most green algae are aquatic
  - occur in fresh water, although a few groups are marine
  - reproduce both sexually and asexually
* Some green algae are multicellular
  - do have alternation of generations
  - is found in snow, soil, on tree trunks and in symbiosis with other organisms
* are an important source of food for many aquatic animals
  - oxygen and food for aquatic organisms
* are by far the most abundant algae
  - complex group and have led to the evolution of land plants
  - considered the most closely related to higher plants
  - diverse, and are presumed to be the ancestors of green plants
  - named for their grass-green chloroplasts
  - the most common algae in ponds and can be multicellular
* are the most diverse and familiar algae in freshwater
  - widespread group of algae
  - plant like of the algae
  - protists most closely related to plants
* are thought to be ancestors of the first plants
  - in the evolutionary line that gave rise to the first land plants
* can be unicellular, colonial, or multicellular
  - divide into more than two daughter cells
  - make their own food through a process of photosynthesis
* contain bright, grass-green pigments, and are more abundant than all the other groups.
* do better than red and brown algae in the strong light of shallow water.
* feeds on nitrates and phosphates.
* give pond water a slightly green colour.
* grow in both warm and cold seas.
* grows all over and turns the water into a cloudy, green swamp.
* has a special adaptation
  - the same pigments as plants, uses starch, and has cell walls of cellulose
* have a cellulose wall and other polysaccharides
  - cells with nuclei
* is algae
  - fairly natural
  - marine organisms
  - mineral and protein poor
  - present when there lot of nitrogen in the water which comes from waste
* occur in all seas and in most fresh-water habitats.
* producer in the ocean's food web.
* show great diversity of form and live in a variety of habitats.
* store their energy as starch.
* type of algae that is considered to be very closely related to plants.

Harmful algae
* Some harmful algae can exist in sediment in a dormant form called a cyst.
* are microscopic, single-celled plants that live in the sea
  - microscopic,single-celled plants that live in the sea

### microalgae:

Marine algae
* are also a good source of biogas for energy, can production rates be calculated
  - nonvascular plants
  - rich in iodine and other essential minerals
* can provide shelter for such organisms as nudibranchs and hermit crabs.
* contain a preponderance of all pigments known to exist.
* produce a variety of secondary metabolites that functionas herbivore deterrents
  - food for intertidal grazers
* provide shelter for nudibranches and hermit crabs.
+ Rock pool, Tide pool zones, from shallow to deep, High tide zone: Biomes :: Habitats
  * The high tide zone is flooded for hours during each high tide. Organisms must survive wave action, currents, and  exposure to the sun. The high tide zone is inhabited by sea anemones, starfish, chitons, crabs, green algae, and mussels. Marine algae can provide shelter for such organisms as nudibranchs and hermit crabs.

Microscopic algae
* Some microscopic algae are also in Lichens.
* are food for microscopic animal plankton
* are the primary producers of dissolved oxygen in pond water
  - source of much of Earth 's oxygen
+ Phycology: Algae
  * Phycology is also the study of prokaryotic forms known as blue-green algae or cyanobacteria. Some microscopic algae are also in Lichens.