KINGDOM : PROTISTA
( The Very First)
( The Very First)
Termed by Ernest Haeckel (1866) [John Hogg
called Protocista]
GENERAL
CHARACTERISTICS:
1. UNICELLULAR and Eukaryotic, SOLITARY OR
COLONIAL
2. IF COLONIAL, ALL CELLS SIMILAR WITH SIMILAR FUNCTIONS,
3. Need
water based environment, fresh/marine or snow or damp soil
4. all aerobic
,mitochondria for cellular respiration
5. Some with chloroplast and can do
photosynthesis
6. Reproduction: asexual or Sexual
7. cyst formation for Perination.
PLANT LIKE PROTISTS
DIVISION:
CHRYSOPHYTA (GOLDEN BROWN ALGAE & DIATOMS)
n Golden
Brown Algae (nanoplanktons): free swimming, unicellular, but
some filamentous &colonial forms. Some lack cell wall & others have
pectic walls.1-2 flagella, mostly photosynthetic (Ch. a & c, carotenoides
& xanthophylls). Founder of the marine food chain.
n Diatoms
(Bacillarophyta) related group. Finely sculptured cell wall,
aquatic, part of marine food web “pastures of sea”. Unicellular & solitary,
either radially symmetrical & non motile (Centrales) or bilaterally
symmetrical showing gliding motion (Pennales). Cell called FRUSTULE has two
openings (outer Epitheca & inner Hypotheca),edges are incurved to form
Girdles. A linear perforation forming longitudinal slit (Raphe) is present at
the back of each valve. Cell wall highly Siliceous. Chromatophores are Golden-Green
or Golden-Brown ( Ch. a & c, beta carotene, Xanthin complex). Reserve food
is FAT & VOLUTIN. Reproduction: Asexual (auxospores) Sexual (isogamy or
oogamy). ECONOMIC IMP: contribute to the dry matter of photosynthetic produce
(pasture of sea), Diatomaceous earth/Diatomite (Siliceous cell wall deposits) ,
used in water filters, abrasive, add sparkling quality to products like paints
used on roads & fingernail polish.
 |
| A Typical Chrysophyta |
DIVISION: PYRROPHYTA (DINOFLAGELLATA)
Dinoflagellata means “Whirling Swimmer”,
Unicellular photosynthetic organisms having TWO Flagella, Nucleus very large with
high amount of DNA(Mesokaryon), Some without cell wall & some with
cellulosic wall, {Largest is Noctiluca} mostly marine as phytoplanctons (source of food in food chain),
Pyrrophyta means “fire plant” for their ability of BIOLUMINISCENCE(eg.
Noctiluca emits a bright blue-green light when disturbed), green pigments are
often masked by red pigments sometimes causing “Red Tides”(eg. Gonyaulax
&Protocentrum) accumulation of which kill many marine organisms as
Dinoflagellata produce powerful toxins (saxitoxin, brevitoxin) causing
respiratory failure. Accumulation of these organisms in pearls & oysters
through Food Chain results in “Shell fish poisoning”, Chromatophores contain
Ch.a &c, carotenes, xanthin & peridinin. Reserve food as Fat & Oil
, Reproduction primarily asexual( long. Cell div.) Some also called “Fire
Algae” eg. Noctiluca,
Gonyaulax.
 |
| Dinoflagellata Structure |
DIVISION: EUGLENOPHYTA
(EUGLENOIDS) [Euglena = “True Eye”]
Mostly Freshwater, Unicellular, Naked, Motile form, Lack rigid
outer covering (Euglenoid movement), Chromatophore discoid or stellate, Photosynthetic
pigment Ch.a & b, B-carotene, Xanthophyll (Close resemblance to
chlorophycean algae), Reserve Food is PARAMYLUM STARCH, Nutrition Generally
MYXOTROPHIC. Cells flagellate attachment near gullet or eye spot. Reproduction
by Long. Fission, Sexual rep. absent. Perinnation through cysts.
 |
| A Typical Euglenoid |
FUNGUS LIKE PROTISTA
ACRASIOMYCOTA (CELLULAR SLIME MOULD)
About 70 spp., MOSTLY LOOK
& BEHAVE LIKE AMOEBA, working with Pseudopodia, During starvation they
aggregate to form mass called SLUG which transform into fruiting body.(tips
contain dormant amoeba like spores) some spores fuse to show sexual
reproduction before release, on release these spores form new amoeba and
continue life cycle.eg. Dictyostelium discoideum.
MYXOMYCOTA (PLASMODIAL OR
ACELLULAR SLIME MOULD)
About 500 spp., bizarre
organisms stream like plasmodium (non walled, multinucleate mass of protoplasm)
; during feeding phase they may be coloured & reproduce asexually. During
food shortage they migrate rapidly to a new area and form a spored Fruiting structure
(sporangium), spores are highly resistant (performs meiosis to produce swarm
cells acting as gamets) Fusion of gametes form new plasmodium. Physarum,
Arcyria, Fuligo, Tubifera.
OOMYCOTA (“Egg Fungi”)
500
spp. Of “water moulds and downy mildew”. Filamentous protists, saprophytes;
large round Oogonia (oogamous sexual reproduction), cell wall made of cellulose
& glycans (Plant like) or Chitin (Fungus like) or both. More closely linked
to “brown Algae” then Fungus. DISEASES: - (a) Sprolegnia cause lesions on fish skin in fish farms & parasite
on other aquatic invertebrates. (b) Albugo
candida cause “white rust of crucifers”. (c) Downy Mildew of Lettuce, corn,
cabbage etc.. (d) Phytophthora infestans
cause “Late blight of Potato”. (e) Plasmopera viticola cause “Downy mildew
of Grapes”.
 |
| Egg Fungi |
ANIMAL
LIKE PROTISTS
Ø Term “Protozoa” coined by G.A. Goldfuss (1848) while Richard Owen (1861)
called them “Acrita”
Ø Acellular or Protoplasmic level of body organization. Osmoregulation by
contractile vacuole in free living forms, Nitrogenous excretion as ammonia, Nutrition
Holozioc (amoeba)/ Holophytic (Euglena)/ Saprophytic (Mastigamoeba), Gaseous exchange through
diffusion of gases.
Ø Fossilized forms of Shelled protozoa (Arcella, Difflugia, Elphidium,
Foraminiferans) are associated with Petroleum bearing formations. Continuous
Internal Skeleton between ecto-/endo-plasm is found in Radiolarians.
Ø 7 -Phylum: Sarcomastigophora, Labyrinthomorpha,
Apicomplexa, Microspora, Acetospora, Myxozoa, Ciliophora.
Ø Sarcomastigophora (Largest Phylum):
Sarcodina (eg. Amoeba) and Mastigophora/Flagellata (eg. Trypanosoma)
Ø AMOEBA: discovered by Rosenhoff
(1757) & named by Saint-Vincent (Greek God amoibe means “to Change”}. It lives in fresh water & grow in
lab by “Hay Infusion Method”. Locomotion by Pseudopodia (Lobopodia), amoeboid
movement based on “Sol Gel Theory” given by Hyman (1917) supported by Pantin
(1923) & Mast (1926). Nucleus is solid & biconcave containing 500-600
chromatin granules.(290 billion bp in its genome).
Ø Entamoeba
histolytica (amoebic dysentery/Amoebiasis) E. gingivalis (Pyorrhoea/bleeding gums). Most common medicine for
Amoebiasis is Metragyl or Flagyl. Entamoeba
coli lives in Human Colon (commensal).
Ø ZOOMASTIGOPHORA: Trypanosoma gambiense (Gambian/African sleeping sickness spread
by Tse-Tse fly Glossina palpalis) &
T.rhodesiense (Rhodesian/East-central
African Trypanosomiasis). T. cruzi (Chaga’s
disease or South American Trypanosomiasis spread by bugs like Triatoma).
Ø Giardia
intestinalis (colon of man) cause Giardiasis.
Ø Leishmania
donovani cause Kala Azar (visceral Leishmaniasis/ Dum-Dum Fever)
affecting Liver, spleen, bone marrow & intestinal villi, spread through
Sandy Fly (Phlebotomus). L.tropica cause Oriental sore (Cutaneous
leishmaniasis). L.brasiliansis causes
‘Espundia’ or “Naso-Oral Leishmaniasis” in S. America.
 |
| Protozoan Protists |
Ø SPOROZOA (exclusively parasites): No
locomotory organ (wriggling movement). Reproduction by spore formation. No
contractile vacuole, complex life history. (a) Plasmodium cause Malaria (spread by female anopheles mosquito) (b)
Monocystis parasitise the seminal
vesicles of earthworm (c) Eimeria cause
coccidiosis in rabbit & chicken (d) Babesia
cause hemoglobinurea fever in cattle.
Ø Malaria (“Bad air”): - Plasmodium
was discovered by Alphonse Laveran (1880). Ronald Ross (Nobel Prize in 1902)
described the life history of Plasmodium in female Anopheles. Out of 60 only
four species of Plasmodium parasitizes man (P.vivax,
P.ovale, P.malariae, P.falciparum). Sporozoite is the infective stage in
human. “Hematin” is the Toxin.
 |
| courtsey online biology notes |
Malaria Type/
agent
|
Disease
|
Pre patent
period
|
Incubation
period
|
Pigmentation in
RBC
|
Diagnosis
|
|
1
|
P. vivax
|
Benign Tertian Malaria
|
8 days
|
14 days
|
Schuffner’s Dot
|
PCR technique
|
2
|
P. malariae
|
8 days
|
30 days
|
Ziemann’s Dot
|
Giemsa stain
|
|
3
|
P. ovale
|
Mild Tertian Malaria
|
12 days
|
14 days
|
||
4
|
P. falciparum
|
Sub
tertian/Estivo-autumnal /Malignant malaria
|
4 days
|
12 days
|
Maurer’s Dot
|
Ø Balantidium
coli (Largest
Protozoa) only ciliate of medical importance parasitizing human
beings (colon & caecum). It produces Hyaluronidase to invade mucous.
Contaminated food & water (oral) cause infection.
Ø Paramecium
(Slipper Animalcule) is a free living ciliate. Body
contains pellicle, caudal tuft, Trichocyst (for offense & defense), Macro-
/Micro-nucleus, two contractile vacuole, cytostome (mouth) &
cytopyge/cytoproct (anus). Paramecium is a filter feeder; it has Kappa/Lambda/Mu/Pi
particles in cytoplasm.
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