Classification of protista part 3 #shorts #viral #biology

Classification of protista part 3 #shorts #viral #biology Shorts, Viral, Neet, Biology, Bio, biological classification class 11, protista classification, protista, microbial eukaryotes, algae types, eukaryotic organisms, algae, protist diversity, protozoa examples, single-celled organisms, protist ecology, unicellular life, biology, bacteria, protozoa types, eukaryote groups, unicellular organisms, microbial diversity, fungi-like protists, eukaryotic microorganisms, microbiology, protozoa species, taxonomy protista, microscope, algae groups
These organisms are mostly marine and photosynthetic.
They appear yellow, green, brown, blue or red depending
on the main pigments present in their cells. The cell wall
has stiff cellulose plates on the outer surface. Most of
them have two flagella; one lies longitudinally and the
other transversely in a furrow between the wall plates.
Very often, red dinoflagellates (Example: Gonyaulax)
undergo such rapid multiplication that they make the
sea appear red (red tides). Toxins released by such large
numbers may even kill other marine animals such as
fishes.
2.2.3 Euglenoids
Majority of them are fresh water organisms found in
stagnant water. Instead of a cell wall, they have a protein
rich layer called pellicle which makes their body flexible.
They have two flagella, a short and a long one. Though
they are photosynthetic in the presence of sunlight, when
deprived of sunlight they behave like heterotrophs by
predating on other smaller organisms. Interestingly, the
pigments of euglenoids are identical to those present in
higher plants. Example: Euglena (Figure 2.4b).
2.2.4 Slime Moulds
Slime moulds are saprophytic protists. The body moves
along decaying twigs and leaves engulfing organic
material. Under suitable conditions, they form an
aggregation called plasmodium which may grow and
spread over several feet. During unfavourable conditions,
the plasmodium differentiates and forms fruiting bodies
bearing spores at their tips. The spores possess true walls.
They are extremely resistant and survive for many years,
even under adverse conditions. The spores are dispersed
by air currents.
2.2.5 Protozoans
All protozoans are heterotrophs and live as predators or
parasites. They are believed to be primitive relatives of
animals. There are four major groups of protozoans.
Amoeboid protozoans: These organisms live in fresh
water, sea water or moist soil. They move and capture