1. General Biology(ZOOLOGY) first semester
2024-2023
Lecture 3 :Kingdom of Animal
The animals kingdom is often distinguished into two major
categories: Non –Chordates (Invertebrates). Animals
possessing notochord are called Chordates.
Subkingdom Protozoa (single-celled animals): Protozoans are first
formed animals, small microscopic animalcules. Some of them
are spherical, oval, ball shaped, while some other are shapeless
(or) irregular. Symmetry: Radial, bilateral symmetry and
Asymmetrical.
Locomotion: Locomotor organelles are pseudopodia or
flagella or hair like cilia or absent.
Nutrition: holozoic (animal like), holophytic (plant like),
saprozoic or parasitic. Digestion occurs intracellular inside of
food vacuoles.
2. General Biology(ZOOLOGY) first semester
2024-2023
Respiration: No special respiratory organs. Respiration is
carried by general body surface through diffusion.
Excretion: Through diffusion or through contractile
vacuoles which serves mainly for osmoregulation.
Reproduction: Asexually and Sexually. Asexual
reproduction by binary fission, multiple fission or budding.
Sexual reproduction by conjugation or by fusion of gametes
(syngamy).
The Sub-kingdom protozoa is classified in to four phyla:
• Phylum : Mastigophora
• Phylum : Sporozoa
• Phylum : Sarcodina
• Phylum : Ciliophora
● Phylum (I):Mastigophora
• Locomotory organs are flagella
3. General Biology(ZOOLOGY) first semester
2024-2023
• Body is covered by protective Pellicle.
This phylum divided into two classes:
1. Phytomastigophora, 2. Zoomastigophora.
The class Zoomastigophora characterized by the lack of
Chlorophil, Nutrition is holozoic or saprozoic mostly parasitic,
the reserve food is glycogen.
Examples: Giardia, Leishmania , Trypanosoma and
Trichomonas.
Giardia lamblia is an intestinal parasite causes giardiasis,
a diarrheal disease in man. This pathogen grow generally in the
small intestine of humans and other animals. Cysts are slightly
smaller, oval and thick walled. Infection occurs by ingestion of
cysts through food and water. The cysts migrate with ingested
food to the small intestine where they produce trophozoites.
4. General Biology(ZOOLOGY) first semester
2024-2023
Trypanosoma spp. are blood parasites of vertebrates, but
most of them are transmitted by invertebrate vectors [Genus:
Glossina]. Man has three species of Trypanosoma as parasites-
Trypanosoma gambiense, T. rhodesiense, and T. cruzi
There four morphological states based on the position of
flagella:
1)Amastigote. 2) Promastigote. 3)
Epimastigote.4)Trypomastigote.
Leishmania spp.
Leishmania tropica, L. mexicana, and L. braziliensis,
predominantly leads to cutaneous leishmaniasis (Baghdad boil)
, an infection of skin or of mucosae of mouth and nose,
while L. donovani causes visceral leishmaniasis, a killing
disease. Infection occurs primarily in spleen and liver and
secondarily in bone marrow, intestinal villi. The disease is called
5. General Biology(ZOOLOGY) first semester
2024-2023
Kala-azar.
Trichomonas
Trichomonas vaginalis is the vaginal parasite responsible for
trichomoniasis
Phylum (2):Ciliophora
● Locomotor and feeding organelles are cilia.
• Body covered with hard pellicle and possess cilia all over the
body.
6. General Biology(ZOOLOGY) first semester
2024-2023
• Micro nucleus and macronucleus are present.
• one or more contractile vacuoles are present.
• Ex: Praramoecium and Balantidium,.
● Phylum (3): Sarcodina
● Locomotary organs are Pseudopodia and help in food
capturing.
• Mostly free living some are parasites.
• Nutrition is holozoic or saprozoic.
• Food vacuoles, contractile vacuoles are present.
Eg: Amoeba and Entamoeba.
Entamoeba histolytica is a very common parasite and is
endemic in warm climates. The symptoms of amoebasis are
highly variable, ranging from an asymptomatic infection to
diarrhea accompanied by blood and mucous, appendicitis, and
abscesses in the liver, lungs, or brain.
Entamoeba coli is a non-
pathogenic species of Entamoeba that frequently exists as
a commensal parasite in the human gastrointestinal tract
Phylum (4): Apicomplexa (Sporozoates)
● Locomotory organelles are absent
• Exclusively endoparasites.
• Body is covered by protective pellicle.
7. General Biology(ZOOLOGY) first semester
2024-2023
• Asexual reproduction - multiple fission.
• Sexual reproduction - fusion of micro and
macrogametes.
Ex: Plasmodium and Taxoplasma
Toxoplasma gondii
Toxoplasma gondii is a protozoan parasite that infects humans
as well as many other animals such as pig, and sheep; it is the
causative agent of an infectious disease known
as Toxoplasmosis.
Plasmodium:
Plasmodium belongs to class Sporozoa in Apicomplexa and
causes malaria. It lives in vertebrate tissue and blood cells. The
parasite transmitted by an insect vector. Schizogony occurs
in vertebrate host, whereas sporogony occurs in insect. No
special organ of locomotion like flagella or cilia is present. Ex
:P. malariae ,P. vivax
P. falciparum
