Parasitology: Hosts and Protozoa

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Questions and Answers

What is the characteristic of the locomotor organelles in Sarcomina?

Cilia

Flagella

Whip-like structures

Pseudopodia (correct)

Which type of protozoa lacks locomotory organelles?

Mastigophora

Ciliophora

Sarcomina

Sporozoa (correct)

What is the primary function of ectoplasm in Amoeba?

Feeds on dead plants and animal debris

Helps in movement, feeding, and protection (correct)

Houses nucleus and mitochondria

Pumps out excess water

How do protozoa like Trichomonas obtain their nutrition?

Feed on dead plants and animal debris Signup and view all the answers

What is the characteristic of the movement in Mastigophora?

Whip-like movement Signup and view all the answers

Which protozoan group is characterized by the presence of flagella?

Mastigophora Signup and view all the answers

What is the primary function of contractile vacuoles in freshwater protozoa?

Pumps out excess water Signup and view all the answers

What is the characteristic feature of movement in the protozoan group, Sarcomina?

Pseudopodia Signup and view all the answers

What is the characteristic feature of the protozoan group, Ciliata/Ciliophora?

Movement by cilia Signup and view all the answers

Which of the following is a non-motile form of protozoa?

Sporozoa Signup and view all the answers

Which protozoan is responsible for causing malaria?

Plasmodium Signup and view all the answers

What is the function of the cyst stage in the life cycle of protozoa?

Latent survival form Signup and view all the answers

What is the term for a living carrier that transports a pathogenic organism from an infected to a non-infected host?

Vector Signup and view all the answers

What type of parasite must be parasitic in order to survive?

Obligate parasite Signup and view all the answers

What is the study of parasites, their hosts, and the relationship between them?

Parasitology Signup and view all the answers

What type of parasite lives within another living organism?

Endoparasite Signup and view all the answers

What is an example of a multicellular parasitic organism?

Helminth Signup and view all the answers

What is the term for a parasite that can be parasitic, but is also capable of free-living existence?

Facultative parasite Signup and view all the answers

Study Notes

Hosts

Host: an organism in which parasites live and cause harm
Definitive Host: harbors the adult or sexual stage of the parasites, or the sexual phase of the parasites' life cycle
Intermediate Host: harbors the larval or asexual stage of the parasites, or the asexual phase of its life cycle

Protozoa

Characteristics: unicellular, can be free-living or parasitic, have locomotive organelles (e.g. flagella, cilia)
Sarcodina: eukaryotic, resemble animal cells, contain major cell organelles (nucleus, mitochondria), move by pseudopodia
Amoeba: Entamoeba histolytica, cytoplasm divided into ectoplasm and endoplasm, ectoplasm helps in movement, feeding, and protection, endoplasm houses nucleus, mitochondria, and food
Mastigophora (Flagellates): move by flagella, have eyespot to detect light changes, respond to light and learn by trial and error, examples include Giardia (intestinal parasite), Trypanosoma (blood pathogen), and Trichomonas (reproductive tract pathogen)
Ciliophora (Ciliates): move by cilia, some have special cilia for feeding and attachment, most are harmless, except Balantidium coli which causes dysentery

Locomotion

Sarcodina: move by pseudopodia
Mastigophora: move by flagella
Ciliophora: move by cilia

Sporoza

Characteristics: nonmotile, developed sexual and asexual stages, entire group is parasitic and harmful
Examples: Plasmodium (causative agent of Malaria), Toxoplasma (cause Toxoplasmosis)

Reproduction

Asexual Methods: budding, fission, schizogony
Sexual Methods: conjugation, gametogony

Life Stages of Protozoa

Cyst: latent survival form
Trophozoite: active motile stage of protozoan parasite or active pathogenic vegetative state

Normal Flora

Oral Cavity: normal flora of the oral cavity
Digestive Tract: normal flora of the digestive tract
Genitourinary Tract: normal flora of the genitourinary tract, Staphylococcus aureus as an opportunistic pathogen

Parasitology

Definition: branch of microbiology that deals with the study of the phenomenon of dependence of one living organism on another
Parasites: a living organism that acquires some of its basic nutritional requirements through contact with another living organism
Zoonosis: a parasitic disease in which the animal is normally the host, but which also infects man
Vector: a living carrier (e.g. arthropod) that transports a pathogenic organism from the infected to non-infected host
Facultative Parasites: organisms that can be parasitic, but are capable of free-living existence
Obligate Parasites: organisms that must be parasitic to survive, e.g. Protozoa (Plasmodium)
Metazoa: multicellular organisms, e.g. helminths (worms), arthropods (ticks, lice)
Endoparasite: a parasite that lives within another living organism, e.g. malaria, giardia
Ectoparasite: a parasite that lives on the external surface of another organism, e.g. ticks, lice

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Description

Learn about the different types of hosts, including definitive and intermediate hosts, and the characteristics of protozoa, including their morphology and locomotive features. Understand the differences between sporozoa and sarcodina.