Follow us  

Life

Protista knowledge
20102181441261AAA_foto_proti_alghe2

Autotrophic protista

They can perform photosynthesis and mainly consist of unicellular algae. They can be divided into a number of systematic groups according to the shape of their cells and the type of photosynthetic pigments they use.

• Chrysophyta or golden algae: they live in both sea and freshwater; the most common ones are diatoms, which are equipped with a typical siliceous shell (SiO2), consisting of two parts joined with each other like a box and a lid. The shell is provided with many small holes through which the cell communicates with the external environment. Diatoms usually live near the seabed.
• Dinoflagellata: they generally live in the sea and are also equipped with a shell, consisting of many cellulose plates. They have two flagella (resembling cilia, only longer) for covering small distances. They are among the most important components of the marine phytoplankton.
• Euglenida: they live in ponds and lakes. These organisms are provided with chloroplasts (cellular organelles containing chlorophyll, the pigment involved in the photosynthesis) and can therefore perform the photosynthesis; however, without light, they become heterotrophic and start therefore feeding on the organic substances they find in the surrounding environment. Their cell is equipped with two flagella and an eyespot, i.e. a concentration of light-sensitive pigments that allow Protista to move towards light.

 

More info

A super-milk
Some protozoa have attracted the interest of the biotechnological research world...

Read all the Curiosities

Related topics

Life
The discovery of fermented bacteria
One of the main pioneers of microbiology was the French...
Read more

Life
The first organisms
Bacteria have been the very first organisms to live on...
Read more