1. Dr. Arun B. Sawarkar, Department of Zoology, BP Arts, SMA Science & KKC Commerce College, Chalisgaon 1 | P a g e
Zoology paper I
ZOO 101: ANIMAL DIVERSITY I
Unit 1: Kingdom Protista 4
General characters and classification up to classes;
Locomotory Organelles and locomotion in Protozoa
All single celled organisms are placed under the Kingdom
Protista. The term Protista was first used by Ernst Haeckel in
the year 1886. This kingdom forms a link between other
kingdoms of plants, animals and fungi. Protists represent an
important step in early evolution. The first protists evolved
probably 1.7 billion years ago. Members of Protista are
primarily aquatic in nature. It is a very large group
comprising of at least 16 phyla. Many protists like algae are
the primary producers in the aquatic ecosystem, some
protists are responsible for serious human diseases like
malaria and sleeping sickness.
1.1 General characters of Kingdom Protista
1) They are simple eukaryotic organisms.
2) Most of the organisms are unicellular, some are
colonial and some are multicellular like algae.
3) Most of the protists live in water, some in moist soil or
even the body of human and plants.
4) These organisms have contains a well-defined nucleus
and other membrane-bound organelles.
5) They have mitochondria for cellular respiration and
some have chloroplasts for photosynthesis.
6) Some protists have flagella or cilia for locomotion.
7) Nuclei of protists contain multiple DNA strands.
8) Reproduction in protists is both asexual and sexual.
Protists are grouped into 3 general categories:
1. Animal-like - referred to as protozoans (pro means
'first,' and zo refers to 'animals'..the first animals)
2. Plant-like - referred to as algae
3. Fungus-like - referred to as slime molds (decompose
and recycle organic material) and water molds (thrive
on dead or decaying organic matter).
General Characteristics of phylum Protozoa
1. They are unicellular.
2. Mostly they are aquatic, either free living or parasitic or
3. Single cell organism performs all the vital activities like
a whole body.
4. Body of protozoa is either naked or covered by a
5. Locomotary organs are pseudopodia or cilia or flagella
or even absent.
6. Nutrition are holophytic (like plant) or holozoic (like
animal) or saprophytic or parasitic.
2. Dr. Arun B. Sawarkar, Department of Zoology, BP Arts, SMA Science & KKC Commerce College, Chalisgaon 2 | P a g e
7. Digestion is intracellular, occurs in food vacuoles.
8. Respiration through the body surface.
9. Asexually reproduction is through binary fission or
10. Sexual reproduction is by syngamy conjugation.
1.2 Classification of Protozoa:
The phylum Protozoa bears unicellular animals. They are
hetetotrophs. Around 30,000 species are known in the world,
of which 10,000 species are pathogenic. The phylum protozoa
is divided into four subphylum as follows.
Subphylum 1: Sarcomastigophora
Single type of nucleus present
Flagella, pseudopodia or both locomotory organelles.
Superclass I. Mastigophora (Flagellata)
One or more flagella are present.
Simple, primitive wall or pellicle present.
Nutrition autotrophic or heterotrophic or both.
Class 1. Phytomastigophorea
Chloroplasts (chlorophyll) is present.
Nutrition mainly holophytic.
Reserve food is starch and fat
Flagella one or two.
Ex. Euglena, Volvox
Class 2. Zoomastigophorea
Chloroplasts (chlorophyll) is absent.
Nutrition mainly holophytic or saprozoic.
Reserve food is glycogen.
Flagella one or many.
Ex. Leishmania, Trypanosoma
Superclass II. Opalinata
Entire body surface covered
by numerous cilia.
They are parasitic.
Reproduction by binary fission.
Class 1. Opalinatea
One or more nuclei are present.
They live as commensal or parasite in the gut of
Superclass III. Sarcodina (Rhizopoda)
Locomotion by Pseudopodia.
Mostly free living.
Asexual reproduction by fission.
Class 1. Rhizopodea
Locomotion by lobopodia, filopodia or reticulopodia.
Pseudopodia help to change their shape and in
capturing and engulfing food.
The cytoplasm is usually divisible into ectoplasm and
Examples: Amoeba, Entamoeba, Dientamoeba
3. Dr. Arun B. Sawarkar, Department of Zoology, BP Arts, SMA Science & KKC Commerce College, Chalisgaon 3 | P a g e
Class 2. Actinopodea
Body usually spherical.
Pseudopodia are in the form of axopodia
with axial filaments.
Class 3. Piroplasmea
Small parasites located in red blood cells of vertebrates.
Locomotory structure are absent.
Subphylum II Sporozoa
Locomotory organ is absent.
Contractile vacuoles are absent.
Body covered with pellicle.
Class 1. Telosporea
Spores without capsules.
Body is naked or encysted.
Reproduction by asexual and sexual.
They are blood and gut parasites.
Ex: Plasmodium, Monocystis
Class 2. Toxoplasmea
Only asexual reproduction.
Class 3. Haplosporea
Spore cases present.
Only asexual reproduction.
Subphyllum III Cnidospora
Spores with polar filaments present.
Class 1. Myxosporidea
Spores large, bears several nuclei.
Endoparasite mostly in fishes.
Class 2: Microsporidea
Spores small with one nucleus.
Endoparasites in arthropods and fishes.
Subphylum IV: Ciliophora
Locomotion by cilia.
Two types of nuclei i.e. meganuclei and micronuclei.
Asexual reproduction by binary fission and budding.
Sexual reproduction by conjugation.
Class 1 Ciliata
Locomotary organ is Cilia.
Body covered by pellicle.
Asexual reproduction by binary fission and sexual
reproduction by conjugation.
Nuclei two types i.e. macronucleus and micronucleus.
Contractile vacuoles are usually present.
Examples: Paramecium, Vorticella, Balantidium
4. Dr. Arun B. Sawarkar, Department of Zoology, BP Arts, SMA Science & KKC Commerce College, Chalisgaon 4 | P a g e
1.3 Locomotory Organelles and locomotion in Protozoa
Different modes of locomotion are reported in Protozoa due to the
presence of different types of locomotory organelles in them. Thus,
the various modes of locomotion found in Protozoa are as follows:
1. Amoeboid movement performed by pseudopodia and
characteristic of Amoeba.
2. Flagellar locomotion performed by flagella and characteristic of
flagellates like Euglena.
3. Ciliary locomotion performed by cilia and characteristic of
ciliates like Paramaecium.
4. Gliding movement or metabolic movement performed by
mynemes and characteristics of sporozoan like Plasmodium.
A. Amoeboid movement
Amoeba moves from one place to other by pseudopodia.
The pseudopodia are finger-like temporary processes given out
from any part of the body and withdrawn. The pseudopodium is
formed by the projection of ectoplasm in which endoplasm flows.
During locomotion, active contraction of ectoplasmic tube
(plasmagel) at the posterior end of the body. This leads the
endoplasm (plasmasol) to flow forward into the expanding
pseudopodium. This process involves continuous solation at the
posterior end and gelation at the anterior end. This is called sol-gel
or change of viscosity theory by Mast and Pantin (1925).
According to Mast, amoeboid movement is brought about
by four processes,
i) attachment of Amoeba to the substratum,
ii) solation of plasmagel at the posterior end,
iii) gelation of plasmasol at the anterior advancing pseudopodia,
iv) contraction of plasmagel tube at the posterior end to drive the
B. Flagellar movement
The free-living flagellates like Euglena moves by lashing the
flagellum and by the movement of the whole body. The flagella
need liquid medium for movement or locomotion. Three types of
flagellar movements have been recognized.
a) Simple conical gyration or Screw propeller: According to
Butschli, the flagellum undergoes a series of lateral movements.
The spiral turning of the flagellum like a screw exerts a propelling
5. Dr. Arun B. Sawarkar, Department of Zoology, BP Arts, SMA Science & KKC Commerce College, Chalisgaon 5 | P a g e
action and pulls the animal forwards. Spiral waves arise repeatedly
from the base of the flagellum one after the other and moving
towards the tip.
b) Paddle stroke or Sideways lashing movement: According
to Ulhela and Krijsman (1925) the flagellum beats in a side-ways
lash, which consist of an effective down stroke or bending and a
relaxed recovery stroke or straightening.
In the effective stroke, the flagellum held out rigidly with
slight concavity in the direction of stroke. In the recovery stroke,
however, flagellum strongly curved and is brought out forward
again. Due to such flagellar action animal moves forward.
Generally the flagellum beats obliquely so that during forward
movement the animal also rotates on its longitudinal axis.
c) Undulating movement: The wave like undulations in flagellum,
that either push or pull. The undulatory waves pass from tip to
base, pull the animal forward. As the waves passes from base to tip,
the animal moves backward. When such undulation is spiral they
cause the organism to rotate in opposite direction.
C. Ciliary movement
The ciliates are characterized by the possession of
numerous, small, fine, thread-like ectoplasmic processes, the cilia.
The ciliary movement is like that of flagellar movement.
The cilia can beat forwards or backwards enabling the
animal to swim anteriorly or posteriorly. Normally the animal
swim forwards, the cilia beating backwards but obliquely, the cilia
stiffen and bend backwards rapidly to almost touch the body
surface, this is called the effective stroke; then the cilia become
limp and return slowly to the original vertical position, this is called