Introduction to Protozoa

Flashcards covering key vocabulary and concepts related to Protozoa, their classifications, life cycles, morphological characteristics, and implications for human health.

Protozoa

A diverse group of unicellular eukaryotic organisms classified into four subclasses based on locomotion.

Amoebae (Sarcodina)

Protozoa that move using pseudopodia.

Flagellates (Mastigophora)

Protozoa that typically move via long, whip-like flagella.

Ciliates (Ciliata)

Protozoa that are propelled by cilia that beat in synchronized waves.

Sporozoans (Sporozoa)

Protozoa that lack specialized organelles of motility.

Trophozoite

The motile vegetative stage of protozoa that multiplies via binary fission.

Cyst

The inactive, non-motile, infective stage of protozoa that survives environmental conditions.

Excystation

The process by which a cyst transforms into a trophozoite after ingestion.

Binary fission

A method of asexual reproduction in which a single organism divides into two equal parts.

Morphology

The study of the form and structure of organisms, essential for differentiating protozoan species.

Chromatin

Nuclear DNA that is present as peripheral chromatin and karyosomes.

Karyosome

A small mass of chromatin within the nuclear space also known as an endosome or centrosome.

Axostyle

A supporting rod-like structure found in some flagellates.

Undulating membrane

A membrane with a flagellar rim that aids in the movement of some flagellates.

Cytostome

A rudimentary mouth structure in certain protozoa.

Isospora belli

A protozoan parasite with a life cycle characterized by schizogony and sporogony, and known for its impact on human health.

Cryptosporidium parvum

A protozoan infecting the intestines, significant in immunocompromised individuals and resistant to disinfectants.

Entamoeba histolytica

A pathogenic amoeba causing amoebic dysentery and potentially fatal complications.

Naegleria fowleri

A free-living amoeba that causes fulminant meningoencephalitis and is typically fatal.

Balantidium coli

The only ciliate parasite of humans, primarily affecting those with poor sanitation.

Dientamoeba fragilis

A protozoan previously classified as an amoeba, identified as usually asymptomatic but associated with gastrointestinal symptoms.

Giardia lamblia

The most common protozoan parasite in the USA, causing gastrointestinal symptoms such as diarrhea.

Trophozoite

The active feeding and motile form of certain protozoa.

Oocyst

A cystic stage in the life cycle of certain protozoa involved in transmission.

Cyst wall

A protective structure around the cyst that aids in survival in harsh environments.

Chilomastix mesnili

A non-pathogenic intestinal flagellate that must be differentiated from potentially harmful organisms.