Eukaryotic Microorganisms, Viruses, and Prions

Practice vocabulary flashcards covering eukaryotic microorganisms (fungi, algae, protozoa, helminths), viruses, and prions.

Chitin

The carbohydrate component that forms the cell walls of fungi.

Hyphae

Long, threadlike cells characteristic of microscopic fungi known as molds.

Pseudohyphae

Chains of budding yeast cells that remain attached to one another in a row.

Sporangiospores

Asexual fungal spores formed by successive cleavages within a saclike head called a sporangium.

Conidiospores

Free asexual fungal spores (conidia) that are not enclosed by a spore-bearing sac.

Saprobes

Heterotrophic organisms, including most fungi, that obtain their nutrients from dead plants and animals.

Mycoses

Infections in living host organisms caused by fungi.

Algae

Eukaryotic organisms, usually unicellular or colonial, that perform photosynthesis using chlorophyll a.

Protozoa

Unicellular eukaryotes that lack cell walls and tissues, are generally motile, and feed heterotrophically by engulfing organic matter.

Trophozoite

The motile, active feeding stage in the life cycle of a protozoan.

Cyst

The dormant stage entered by many protozoa to survive unfavorable environmental conditions.

Helminths Classification

Multicellular parasitic worms possessing organ systems, broadly classified into flatworms (cestodes and trematodes) and roundworms (nematodes).

Cestodes

Parasitic flatworms, commonly referred to as tapeworms, which have no definite body cavity.

Trematodes

Parasitic flatworms (flukes) characterized by flattened, nonsegmented bodies with sucking mouthparts.

Nematodes

Parasitic roundworms with a complete digestive tract, a protective surface cuticle, and mouth parts containing spines and hooks.

Obligate Intracellular Parasite

An agent, such as a virus, that requires a living host cell to replicate because it lacks metabolic enzymes and protein synthesis machinery.

Capsid

The protein shell or coat that surrounds and protects the nucleic acid genome of a virus.

Naked Virus

A non-enveloped virus consisting solely of a nucleocapsid without an outer lipid membrane layer.

Bacteriophage

A specialized virus that specifically infects bacterial cells.

Reverse Transcriptase

An enzyme used by retroviruses like HIV to synthesize viral DNA from a viral RNA template.

Cytopathic Effects

Microscopic cell damage and structural alterations in host cells caused by viral infection.

Syncytium

A multinucleated giant host cell formed by the fusion of multiple adjacent cells as a cytopathic result of viral infection.

Persistent Infection

A long-term infection where a virus remains inside the host cell for an extended period, which can be chronic, latent, or oncogenic.

Prion

An infectious proteinaceous particle containing no nucleic acid that causes normal proteins to misfold into abnormal, disease-causing configurations.

Transmissible Spongiform Encephalopathies

Fatal neurodegenerative diseases caused by prions, including scrapie, bovine spongiform encephalopathy (BSE), wasting disease, and Creutzfeldt-Jakob Syndrome (CJS).