18 Questions
What is the main function of the ectoplasm in protozoa?
Ingestion of food
Which part of the cytoplasm in protozoa contains the nucleus?
Endoplasm
What is the function of food vacuoles in protozoa?
Ingestion of food
Which structure in protozoa is responsible for collecting waste products?
Food vacuoles
What is the main function of the nucleus in protozoa?
Reproduction
Where is the chromatin usually located in the nucleus of protozoa?
Distributed along the periphery
How is the nucleus of a vesicular type different from a compact type?
Vesicular nuclei have a central karyosome and peripheral chromatin, while compact nuclei have diffuse compact chromatin.
How do Ciliates primarily achieve locomotion?
By cilia covering the body
Which protozoa group relies on diffusion through the body surface for nutrition?
Flagellates
How do Amoebae primarily excrete waste products?
Through contractile vacuoles
What do protozoa secrete to facilitate various functions?
Material for the cyst wall formation
Which protozoa group utilizes phagocytosis for nutrition?
Amoebae
What is the process of forming cysts that resist unfavorable conditions outside the body and protect against digestive juices in the gastrointestinal tract?
Encystation
Which method of asexual reproduction involves the division of a single parasite into two parasites?
Simple Binary Fission
In which type of reproduction does Plasmodium exhibit the division of nucleus into several parts followed by cytoplasm division?
Schizogony
What is the process in class Sporozoa where male and female gametocytes are formed and unite to produce a zygote?
Gametogony
Which form of reproduction involves the exchange of nuclear material between two organisms?
Conjugation
In which type of reproduction are numerous daughter cells formed after the nucleus undergoes successive divisions within the schizont?
Multiple Binary Fission
Study Notes
Definition and Structure of Protozoa
- Protozoa are microscopic unicellular organisms capable of performing all physiological functions of life.
- They are composed of protoplasm, which is differentiated into nucleoplasm and cytoplasm.
- Cytoplasm consists of outer thin hyaline ectoplasm and inner voluminous granular endoplasm.
- Ectoplasm serves as the organ for locomotion and for engulfment of food.
- Endoplasm contains the nucleus, food vacuoles, storage granules, and excretory vacuoles.
Nucleus
- The nucleus consists of nuclear membrane, nucleoplasm, and chromatin.
- The nucleus is usually single but may be double or multiple.
- Types of nuclei: vesicular (central karyosome, peripheral chromatin dots), compact (diffuse compact chromatin filling the nucleus).
Physiological Functions of Protozoa
- Locomotion:
- By Pseudopodia (amoeboid movement) in Amoebae.
- By Cilia in Ciliates.
- By Flagella (single or multiple) in Flagellates.
- By gliding in Sporozoa.
- Nutrition:
- By ingestion of solid particles by phagocytosis using pseudopodia in Amoebae.
- By cytostome in Ciliates and some Flagellates.
- By diffusion through the body surface in Flagellates and Sporozoa.
- By pinocytosis (liquid form) in Sporozoa.
- Excretion:
- By diffusion through the body surface in Flagellates.
- By contractile vacuoles that rupture to the outside in Amoebae.
- By cytopyge in Ciliates.
- By deposition of waste products (pigment) in the cytoplasm in Sporozoa.
- Secretion:
- Digestive ferments.
- Material for the cyst wall formation.
- Proteolytic enzymes.
- Hemolysins and cytolysins.
- Toxic and antigenic substances.
- Encystation: Formation of cysts that resist unfavorable conditions outside the body and for protection against digestive juice of the gastrointestinal tract.
- Reproduction:
- Asexual Reproduction:
- Simple Binary Fission: a method of asexual reproduction by which a single parasite divides into two parasites.
- Multiple Binary Fission or Schizogony: the nucleus divides into several parts, followed by division of the cytoplasm, forming several daughter cells.
- Sexual Reproduction:
- Conjugation: exchange of nuclear material between two organisms.
- Gametogony: formation of male and female gametocytes, followed by their union (Syngamy) to produce a zygote.
Test your knowledge on the basic concepts of Protozoa as discussed in the Medicine and Surgery lecture by Dr. Mona Faheem. This quiz covers the definition of Protozoa, their structure, and physiological functions.
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