Algae are plantlike, usually microscopic organisms, that conduct photosynthesis like larger plants. Alagaes, however, lack stems, roots and leaves. Not only do they assist in breaking down organic matter, but they also provide organic matter to the soil.
Why should I be aware of this?
- Algae produce more than 71% of the Earth’s oxygen. Some scientists believe that algae produce 87% of the world’s oxygen.
- Algae are one of the most important element in fighting climate change as they help remove huge amounts of Carbon Dioxide from the air.
- They are the basis of most food chains in the ocean and in fresh water. No fish can survive without algae.
- It is becoming an important fuel source.
All about algae
Algae, a large and diverse group of complex-celled photosynthetic organisms, have independently evolved several times in life on Earth, representing a beneficial strategy adopted by parallel evolutionary paths.
All forms of algae evolved from photosynthetic bacteria called cyanobacteria, which is among the first life forms on the planet. It took several billion years for bacteria to evolve into eukaryotic organisms, which are the ancestors of all living plants and animals.
- Algae, which are the primary producers of the marine ecosystem, are consumed by a wide variety of organisms, especially filter feeders.
- Animals that live deep in the oceans depend on dead algae or small animals floating down from above because most photosynthesis in the oceans takes place in the upper 100 m (328 ft). At the deepest level where it is pitch dark, no photosynthesis can occur.
Green and red algae
Green algae plants evolved on land about 500 million years ago. An even more primitive form of algae is Red algae. These are among the first eukaryotic organisms on the planet, and their signatures have been found in rocks 1.2 billion years old.
Seaweeds, which get washed up on beaches around the world, are the most complex algae of both the red and green versions. Most algae groups are usually stationary. The photosynthetic machinery of algae is derived from endosymbiotic cyanobacteria-like organelles called chloroplasts. Eukaryotic organisms is likely to have evolved from extremely closely integrated communities of symbiotic bacteria. Worldwide, there are about 5,000 species of red algae, 2,000 of brown algae and 8,000 of green algae.
Types of algae
The three general forms of algae are planktonic (free-floating), filamentous and attached-erect.
- Planktonic algae usually appear as "pea soup" green masses or brownish colored particles suspended in the water. Some species may cause fishy, musty or septic odor.
- Filamentous algae can be found along the edges or bottom of a pond in the form of large greenish-colored, stringy mats. Some of them may be slimy or cottony in appearance. These algal colonies can fill with gases and float to the surface in large masses.
- Attached-erect algae is often mistaken for a rooted aquatic plant. The most common species, Chara sp., which is commonly called Muskgrass or Stonewort, has an unpleasant musky or garlic odor. Due to calcium deposits on the leaves and stem, it feels gritty when held by hand.
The future of algae
Efforts are on to farm algae on a large scale. Once done, algae could replace petroleum as a source of liquid fuel. Algae as fuel source will enable us to heat our homes, and power our cars while at the same time starting to heal the planet.
- Some algae can live in the snow. 
- Some algae can live in boiling hot water. 
- Some algae seem more like animals than plants. 
- Some algae even hunt and kill fish for food. 
- Fossilized Algae are used to make dynamite. 
Researchers have stumbled on an algae that detoxifies arsenic, potentially opening the way for cleaning up underground water reservoirs. The simple, single-celled algae called Cyanidioschyzon thrives in extremely toxic conditions and chemically modifies arsenic that occurs naturally.
Cyanidioschyzon could some day help reclaim arsenic-laden mine waste and aid in everything from space exploration to creating safer foods and herbicides, scientists said. 
- What is Algae?
- WHAT IS ALGAE?
- Why are algae so important?
- Algae-based cosmetic ingredient set to impact anti-aging market