Introduction to Protozoa

Question 1

Define protozoa

Answer 1

Unicellular eukaryotic organism
microscopic organism

Question 2

Describe kinetoplast

Answer 2

1. Non-nuclear DNA containing body in addition to nucleus.
2. Powerhouse present only in Kinetoplastida protozoa (e.g.,
   Leishmania, Trypanosoma)
3. Flagellum originates from parabasal body near kinetoplast.

Question 3

Differentiate macro and micro nucleus. Give example of protozoa that have both.

Answer 3

Macro: for growth and metabolic activity
Micro: for sexual reproduction
Balantidium Coli

Question 4

Examples of flagella protozoans

Answer 4

Giardia duodenalis
Trypanosoma

Question 5

Disease causing form of Entamoeba histolytica is

Answer 5

Matured quadranucleated cyst

Question 6

Types of excretion in protozoa

Answer 6

1.Osmosis or effusion through ectoplasm
(e.g., Trypanosoma cruzi)
2. Deposition in endoplasm
malarial pigment (e.g., Plasmodium)
3. Contractile vacuoles
burst of ectoplasm (e.g., Entamoeba)
Source: Goog

Question 7

Types of secretion in protozoa

Answer 7

Virulence factors:
Proteolytic enzymes, haemolysins, cytolysins, toxin &
antigenic substances

Protective factors:
Secretory materials form resistant cyst wa

Question 8

Types of reproduction

Answer 8

Asexual:
Simple binary fission (Giardia lamblia)
Endodyogeny (Toxoplasma gondii) Endopolygeny (Toxoplasma gondii) Shizogony (Plasmodium sp.)
Sexual:
Conjugation (Balantidium coli) Copulation (Plasmodium sp.)

Question 9

Differentiate binary fission of flagellates and ciliates

Answer 9

Flagellates: longitudinal
Ciliates: transverse

Question 10

Describe schizogony

Answer 10

1. Multiple fission.
2. Nucleus divides many times
3. Cytoplasm separates and encloses each nucleus.
   Example is plasmodium in RBC

Question 11

Asexual reproduction of toxoplasma gondii are ;

Answer 11

Endodyogeny (tachyzoites and bradyzoites) and endopolygeny (in coccidian stage)

Question 12

Describe sexual and asexual reproduction of plasmodium.

Answer 12

In mosquito (definitive host), plasmodium undergo copulation (sexual rep.). In human (intermediate host), plasmodium undergo schizogony (asexual rep.)

Question 13

Describe copulation

Answer 13

In Sporogony phase of Plasmodium in Mosquito.
male & female gametes > Zygotes > Oocysts

Question 14

Describe conjugation

Answer 14

Temporary union between two ciliates for exchange of
nuclear material without increase in number e.g., Balantidium coli

Question 15

In one stage form of one host form life cycle pattern, what is the example?

Answer 15

Trichomonas vaginalis

Question 16

Describe on transmission by direct life cycle and an example.

Answer 16

1. Intestinal and luminal protozoa
2. directly moves from one host to
   another host or through food or water
3. Examples: E. histolytica, G. duodenalis

Question 17

Describe on transmission by indirect life cycle and an example.

Answer 17

1. Require alternate existence in two hosts:
   Human (vertebrate host) and Mosquito (invertebrate
   host) e.g., Plasmodium
2. Cyclic development occurs in arthropod vector, i.e., mosquito before it attains the infective stage.