The document discusses various groups of animal-like protists. It describes protozoa as unicellular eukaryotic organisms that are mostly aquatic and feed by phagocytosis. It provides details on the supergroups Excavata, Amoeboza, Rhizaria, and Chromalveolata. The Excavata exhibit features related to feeding, the Amoeboza use pseudopodia for movement and feeding, the Rhizaria include shelled foraminifera and radiolarians, and the Chromalveolata feature alveoli and include dinoflagellates, apicomplexans, and ciliates.

1. Animal like protists
Group # 02

2. Table of contents :
What are protists?
Protozoa
Supergroup Excavata
Supergroup Amoeboza
Supergroup Rhizaria
Supergroup Chromalveolata

3. PROTOZOA

4. What are protists?
■ The protists comprise a polyphyletic assemblage comprised of six
groups
• –Plantlike protists- primarily autotrophic (they produce
their own food)
• –Animal-like protists- are primarily heterotrophic (they feed on
other organisms).

5. The Protozoa
• Proto - first , zoa – animals
• Ancestors of all members of Kingdom Animalia
• They are chemorganotrophic organisms
• Unicellular -without tissues and organs
• Minute, Microscopic & Eukaryotic organisms

6. General features and homeostasis
• They are called acellular or non-cellular animals (i.e consists
of protoplasm only)
• HABITAT - mostly aquatic, either free living or parasitic.
• SIZE - most protozoans are in the size of 1 to 10micrometer
long, but Balantidium coli may measure150 micrometer.
• CYTOPLASM – divided into two parts ; ectoplasm and
endoplasm
• MARINE PROTOZOA – are homosmotic (no active
transport)
• FRESH WATER PROTOZOA – homeostasis occurs
• CONTRACTILE VACULE – one large vacule is formed by

8. Feeding habits :
■ Mostly obtain nurtition by :
• Active transport
• Ingestion
• Endocytosis

9. ■Structures :
• Cytophyrnx :
Specialised mouth like region for food ingestion
• Cytophage :
Specifically for release of wastes
• Food vacuoles :
Digestion and transport of food occur . Food vacuoles form
during endocytosis . Enzymes and acidity changes mediate digestion
• Egestion vacuoles :
After digestion is complete, the vacuoles are called egestion vacuoles
and release their waste contents by exocytosis

10. Surface area to volume ratio in
protozoa

11. • Large surface area in proportion to the volume.
• Facilitates two other maintenance functions
1. Gas exchange
2. Excretion
Surface area to volume ratio in protozoa
 Gas exchange
• Involves acquiring oxygen for cellular respiration
• Eliminating the carbon dioxide produced as a byproduct
 Excitation
• Elimination of the nitrogen byproduct of protein metabolism
• Primary by product in protozoa is ammonia

12. Reproduction

13. • Both asexual and sexual reproduction occur among the protozoa.
Asexual reproduction:
• One of the simplest and most common forms of
asexual reproduction is binary
fission (distributed into two
similar-sized individuals, may be
longitudinal or transverse)

14. Sexual reproduction:
• gamete formation.
• Ciliated protozoa are an exception to this pattern.
• Specialized forms of sexual reproduction are covered as individual
protozoan groups are discussed.
• Bud formation
• Multiple fission or
schizogony (formation
of large number of
daughter cells)

15. Supergroup Excavata

16. Introduction:
 The supergroup Excavata includes some of the oldest
eukaryotes.
 Most possess a cytostome characterized by a suspension-
feeding groove ("excavated" groove ,hence the name) with a
posterior-directed flagellum that is used to generate a feeding
current.
 This enables the capture of food particles.
 Those that lack this feature are presumed to have had it at some
time during their evolution.

17. Subgroups of Excavata
There are three subgroups of supergroup excavata:
• Fornicata
• Parabasalia
• Euglenozoa
Fornicata
• They have flagella (for locomotion), a feeding groove, and are
unionucated.
• They have modified mitochondria called mitosomes.
• Fornicata get the energy their from naerobic pathways (glycolysis.)
• They possess a pellicle that gives the body a definitive shape.

18. • The most important member of this group
is Giardia intestinalis, which causes the
waterborne disease (like diarrhea)
giardiasis.
Parabasalia
• Members are flagellated( infect they have many thousand of flagella)
and endosymbionts of animals.
• They have a parabasal body and striated parabasal fibers that
connect the Golgi to the flagella.
• Since they do not have a distinct cytostome, they use phagocytosis to
engulf food items.
• The parabasalids have reduced mitochondria called
hydrogenosomes.

19. • One member of this group is
Trichomonas vaginalis causes
STD(tricomoniasis) in humans.
• About 7 million people are infected
annually in the United States.
Euglenozoa
Members of the Euglenozoa are either
1:Phytoflagelled(photosynthesizing)
2:Zooflagellated (particle-feeding and parasitic)
• The main morphological feature of the euglenozoans is the
presence of spiral or crystalline rod of unknown function inside one
of their flagella.

20. Phytoflagellated Protozoa
• Possess 1 or 2 flagella and produce a large portion of the food
and oxygen in marine.
• Example :Euglena is a freshwater photoflagellated protozoan
• Each chloroplast has a pyrenoid, which
synthesizes and stores polysaccharides.
• In dark, euglenoids feed by absorption and
loose their green color
• Some euglenoids (e.g.,Peranema) lack
chloroplasts and are always heterotrophic.
• The stigma permits light to strike the
photoreceptor from only one direction
,allowing Euglena to orient to a light source.

21. Zooflagellated protozoa
• They lack chloroplasts and are heterotrophic.
• They have a single, large mitochondria that contains an organized
mass of DNA called kinetoplats .
• Some members of this group are important parasites of humans.
• One of the most important species Is Trypanosoma brucei. This
specie is divided into three subspecies:T.b. brucei,T.b.
gambiense, and T.b. rbodesiense.
• The first of these three subspecies is a parasite of nonhuman
mammals of Africa. The latter two cause African sleeping
sickness in humans , Tsetse flies (Glossina app.) are
intermediate hosts and vectors of all three subspecies.
• If this disease is not treated earlier, it may causes death

23. SUPERGROUP
AMEOBOZOA

24. • Members of the Amoebozoa are the amoebae (sing., amoeba).
• When feeding and moving, they form temporary cell
extensions called pseudopodia (Gr. pseudes, false 1 podion, little foot)
Types of pseudopodia:
• Lobopodia (Gr. Lobos, lobe) are broad cell processes containing
ectoplasm and endoplasm and are used for locomotion and
engulfing food.
• Filopodia (L. filum,thread) contain ectoplasm only and provide a
constant 2 way streaming that delivers food in a conveyor-belt
fashion.
• Reticulopodia (L. reticulatus, netlike) are branched and rejoin to
form a netlike series of cell extensions.
• Axopodia (L. axis, axle) are thin, filamentous, and supported by a
central axis of microtubules
Introduction :

26. ■ Tests:
• Some members lack a test, cell wall, or other supporting structures. These amoebae are naked
naked and are normally found on shallow-water substrates of freshwater ponds, lakes, and slow-
slow-moving streams.
• Other members possess a test that may be
calcareous (made of calcium carbonate), proteinaceous
(made of protein), siliceous (made of silica [SiO2]), or chitinous (made of chitin—a polysaccharide).
tests may be
composed of sand or other debris cemented into a secreted
■ Food:
They feed on other protists and bacteria. They engulf food by phagocytosis.
■ Reproduction :
• Binary fission occurs when an amoeba reaches a certain size limit.
• no sexual reproduction is known to occur.

27. • Arcella
Arcella is a common freshwater, shelled
amoeba. It has a brown, proteinaceous
test that is flattened on one side and
domed on the other. Pseudopodia
project from an opening on the flattened
side.
• Difflugia
Difflugia is another common freshwater,
shelled amoeba. Its test is vase shaped
and is composed of mineral particles
embedded in a secreted matrix.

28.  Tubulinea
They can remain moist.
Others are endosymbionts, commensals, or parasites of
nvertebrates, fishes, and mammals.
Amoeba proteus is included in this
group

29.  Acanthamoebida
• Naegleria fowleri and Acanthamoeba
spp.
• These proto-zoans are aerobic
inhabitants of soil and water.
• posses both a flagellated forms.
• Acanthamoebida causes inflammation
of brain tissue known as
meningoencephalitis.
• Naegleria infects the cornea of the
eye, leading to inflammation and
opacity.

30.  Entamoebida
• No flagella or centrioles and lack mitochondria.
• All free-living amoebae are particle feeders, using their
pseudopodia to capture food; a few are patho-genic.
• Entamoeba histolytica causes one form of dysentery in
humans.
• Amoebae live in the folds of the intestinal wall, feeding on
starch and mucoid secretions.
• They pass from one host to another in the form of cyst
transmitted by fecal combination of food and water.
• After injection, leave their cysts and take up residence in
host's intestinal wall, causing a multitude of problems.

31. SUPERGROUP RHIZARIA

32. • These protozoans are amoeboid in morphology.
 Introduction :
• However, molecular phylogenetic analysis makes it clear
that the Amoeboza and Rhizaria are not sister taxa.
• Some members of the Rhizaria have fine needle like
pseudopodia. Filopodia supported by microtubules are
known as axopodia.

33. Subclassification:
Two major subclassifications of Rhizaria include:
• Forams
• Radiolarians
Foraminifera or forams:
 Introduction:
• The name Foramaniferans is derived
from the Latin word foramen, little hole,
and fera, to bear.
• Forams are single celled organisms and
contains shell.
• They are primarily a marine group.

34.  Tests:
• Body of forams are covered by test or shells which
are primarily calcium carbonate.
 Reticulopodia:
• Foraminiferans possess filopodia arranged in a
branching network called reticulopodia which helps in
locomotion and entrapping prey.
 Chambers :
• As foraminiferans grow, they secrete new, larger
chambers that remain attached to the older chambers
in a straight chain and resembles a snail shell.
• Many of these tests become relatively large; for
example, “Mermaid’s pennies,” found in Australia

35.  Importance :
• Foram tests are abundant in the fossil record since the Cambrian period (543
million years ago).
• They make up a large component of marine sediments, and their
accumulation on
the floor of oceans resulted in limestone and chalk deposits.
Example : The white cliffs of Dover in England and the
great Egyptian pyramids
 Heliozoans:
• Heliozoans are aquatic protozoa.
• They are either planktonic (organisms that float
freely in the water.)or live attached by a stalk to some substrate.
• Heliozoans are either naked or enclosed within a test
that contains openings for axopodia

36. RADIOLARIANS:
 Introduction :
• Radiolarians are planktonic marine and freshwater
protozoa.
• The name radiolarian is derived because its members
exhibit radial symmetry
• They are relatively large in size.
• Mostly lives in colony so it is called colonial.
 Tests:
• Tests or shells of radiolarian are silicious i.e made of silica.
 Morphology :
• It's morphology can be simple to complex.
• All members have a porous capsular wall through which

37. • The mitochondria have tubular cristae.
■ Ornamental body:
• Body has long, moveable spines or needles that
gives ornamentations.
 Fossil records:
• When radiolarians die, their tests drift to the ocean
floor.
• Some of the oldest known fossils of eukaryotic
organisms are radiolarians.

38. • The chromalveolates can be either
autotrophic, mixotrophic,or heterotrophic.
• They are all united, however, in the
common feature of plastid origin (the
Plastid appears to have been acquired
by endosymbiosis With an n ancestral
archaeplastid by some and then lost in
others.
• Although there are three first-rank
subgroups within this supergroup, only
one, the Alveolata,will be considered
since it contains the only protozoan
protists.
Super group chromalveolata

39. Subgroup Alveolata
The Alveolata (alveolates) is a large subgroup that
includes :
1. Dinoflagellata (dinoflagellates)
2. Apicomplexa
3. Ciliophoraciliates
 Common trait:
One common trait is the presence of flattened
vesicles called alveoli (hence the name Alveolata)
that are stacked
in a continuous layer below the plasma
membrane.
Functions of alveoli:
The alveoli function in membrane transport,
similar to Golgi bodies.

40. Dinoflagellates:
The name is derived from the Greek
word dinein, meaning“to
whirl.”Dinoflagellates are
• marine-flagellated protozoa
• contain various pigments such as
chlorophyll.
• many dinoflagellates contain
xanthophyll pigments, which gives
them a goldenbrown color.
• Have one flagellum that wraps around the protozoan in a
transverse groove called the girdle.The primary action of this
flagellum causes the protozoan to spin on its axis.
• A 2nd flagellum is a trailing flagellum that pushes the
protozoan forwar

41. • Accumulation of
dinoflagellates colors the
water are also known
"blooms” Or “red tides”
.
• They result in fish kills
along the continental
shelves. Humans who
consume tainted molluscs
or fish may die.
• several members, such
as Gymnodinium, have
representatives that

42. Apicomplexa :
• Members of the Apicomplexa are all parasites.
■ Characteristics:
• Apical complex for penetrating host.
• Single type of nucleus
• No cilia and flagella, except in certain reproductive stages.
• Life cycle that typically include asexual (schizogony,sporogony) and sexual
(gametogony) phases.
• Near all Apicomplexans are parasites of animals and some cause serious disease.
• These parasites spraed through their hosts as tiny infectious cells called sporozoites
• Apicomplexans are so named because one end (the apex) of the sporozoite contains a
complex of organelles specialized for penetrating host cells and Tissues.
• Certain members such as Cryptosporidium, Toxoplasma, Cyclospora, babesia and
Plasmodium cause a variety of diseases in domestic animals and humans.

43. Life Cycle
• Although the life cycles of these
protozoa vary considerably, certain
generalizations are possible.
• Many are intracellular parasites.
■ Schizogony:
• Schizogony is multiple fission of an
asexual stage in host cells to form
many merozoites,that leave the host
cell and infects.

44. ■ Gametogony:
• Sexual phase of the life cycle.
• Either microgametocytes or macrogametocytes are formed.
• Microgametocytes produce biflagellate microgametes.
• The macrogametocyte develops into a single macrogamete.
• A microgamete fertilizes a macrogamete to produce a zygote that becomes enclosed in a
membranous cyst called oocyst.
■ Sporogony:
• The zygote undergoes meiosis and the resulting cells divide repeatedly by mitosis.
• This process called sporogony produces many rodlike sporozoites in the oocyst.
• Sporozoites infect the cells of a new host after the new host.

46. Ciliates:
macronucleus regulates daily metabolic activities..Micronuclei are the genetic reserve
of the cell.
5. Few ciliates are symbiotic.Most ciliates are free living; however, some are
commensalistic or mutualistic, and a few are parasitic.
6. Theyreproduce asexually by binary fission and budding.

47. 7.They reproduce sexually by conjugation.The partners involved are
called conjugants. Many species have numerous mating types, not all of
which are compatible.

48.  Cilia are generally similar to flagella, except
that they are much shorter, more numerous,
and widely distributed over the surface of the
protozoan.
 Basal bodies (kinetosomes) are
interconnected with a network of fibers
believed to anchor the cilia and give shape to
the organism.
 Some have specialized cilia cirri, which are
used in movement.
 Trichocysts are pellicular structures
primarily used for Protection. They are rodlike
or oval organelles oriented perpendicular to
the plasma membrane.

49. ■ Paramecium:
• Some ciliates, such as Paramecium, have a
ciliated oral Groove along one side of the body .
Cilia of the oral groove sweep small food particles
toward the end of the cytopharynx, where a food
vacuole forms.
• When the food vacuole reaches an upper size
limit, it breaks free and circlates through the
endoplasm.
• Indigestible material is voided either through a
temporary opening or through a permanent
cytopyge which is found in many ciliates.
• Some free-living ciliates prey upon other protists or
small animals. Prey capture is usually a case of
fortuitous contact.
■ Didinium:
The ciliate Didinium feeds principally on Paramecium,
a prey that is bigger than itself. Didinium forms a
temporary opening that can greatly enlarge to
consume its prey .

50. ■ Suctorians:
Suctorians are ciliates that live attached to their
substrate.They possess tentacles whose secretions
paralyze prey, often ciliates or amoebae. The tentacles
manipulate the prey, and prey cytoplasm is drawn into
the suctorian through the tentacles and encoporated into
a food vacule within the protist. The mechanism for
this probably involves tentacular microtubules.
.

51. Reference :
 Miller and harley 10th edition book
 https://www.sciencedirect.com/topics/immunology-and-
microbiology/chromalveolata
 https://www.ncbi.nlm.nih.gov/books/NBK8325/
 https://bio.libretexts.org/Bookshelves/Introductory_and_Gen
eral_Biology/Book%3A_General_Biology_(Boundless)/23%
3A_Protists/23.3%3A_Groups_of_Protists/23.3A%3A_Exca
vata
 https://www.biologyonline.com/dictionary/amoebozoa
 https://courses.lumenlearning.com/wm-
biology2/chapter/rhizaria/