What are Algae?

Do you know the algae?

     "Algae are simple plants that can range from the microscopic (microalgae), to large seaweeds (macroalgae), such as giant kelp more than one hundred feet in length. Microalgae include both cyanobacteria, (similar to bacteria, and formerly called “blue-green algae”) as well as green, brown and red algae. There are more varieties of microalgae, but these are the main ones.

      Algae can be grown using water resources such as brackish-, sea-, and wastewater unsuitable for cultivating agricultural crops. When using wastewater, such as municipal, animal and even some industrial runoff, they can help in its treatment and purification, while benefiting from using the nutrients present.

      Most microalgae grow through photosynthesis – by converting sunlight, CO2 and a few nutrients, including nitrogen and phosphorous, into material known as biomass This is called “autotrophic” growth. Other algae can grow in the dark using sugar or starch (called “heterotrophic” growth), or even combine both growth modes (called “mixotrophic” growth).

      Algae are very diverse and found almost everywhere on the planet. They play an important role in many ecosystems, including providing the foundation for the aquatic food chains supporting all fisheries in the oceans and inland, as well as producing about 70 percent of all the air we breathe."

Protistan Diversity

Archaeplastida

This group of eukaryotes includes red algae and green algae, along with land plants (kingdom Plantae). Red algae and green algae include unicellular species, colonial species (such as the green alga Volvox), and multicellular species. Many of the large algae known informally as "seaweeds" are multicellular red or green algae. Protists in Archaeplastida include key photosynthetic species that form the base of the food web in some aquatic communities.

Volvox, a colonial freshwater green alga.

The colony is a hollow ball whose wall is composed of hundreds of biflagellated cells (see inset LM) embedded in a gelatinous matrix. The cells are usually connected by cytoplasmic strands; if isolated, these cells cannot reproduce. The large colonies seen here will eventually release the small "daughter" colonies within them (LM).

Red Algae

Bonnemaisonia hamifera : This red alga has a filamentous form.

Dulse (Palmaria palmata) : This edible species has a "leafy" form.

Nori : The red alga Porphyra is the source of a traditional Japanese food. The seaweed is grown on nets in shallow coastal waters.

Paper-thin, glossy sheets of dried nori make a mineral-rich wrap for rice, seafood, vegetables in sushi.

Multicellular chlorophytes.

Ulva, or sea lettuce: This multicellular, edible chlorophyte has differentiated structures, such as its leaflike blades and a rootlike holdfast that anchors the alga.

Caulerpa, an intertidal chlorophyte : The branched filaments lack cross-walls and thus are multinucleate. In effect, the body of this alga is one huge "supercell."

Algae

Finally, this is a little and cute alga from my microscope!

This essay is not enough for algae of course, so you can visit websites and read biology books also.

To learn importance of algae! : http://nzetc.victoria.ac.nz/tm/scholarly/tei-Bio13Tuat02-t1-body-d2.html

To learn more about algae! : http://allaboutalgae.com/ 

In addition, my main reference : Biology: A Global Approach, Global (Tenth) Edition - PEARSON

Thanks for reading...