The Eukaryotes: Fungi, Algae, Protozoa, and Helminths

Vocabulary flashcards covering key terms and concepts related to eukaryotic pathogens, fungi, algae, protozoa, and parasitic helminths from Chapter 12.

Mycology

The study of fungi.

Thallus

The entire vegetative body of a fungus.

Hyphae

Long, tubular, branching filaments that make up the structure of molds.

Mycelium

A visible mass formed by a collection of intertwined hyphae.

Septate Hypha

A type of fungal hypha containing cross-walls (septa) with pores that divide the filament into distinct cell-like units.

Coenocytic Hypha

A continuous fungal hypha lacking septa, containing an uninterrupted cytoplasm with multiple nuclei.

Pseudohyphae

Short chains of unseparated yeast cells (false hyphae) formed when buds fail to detach.

Germ Tubes

Initial tubular outgrowths of true hyphae produced by Candida albicans that facilitate tissue invasion and increase virulence.

Fungal Dimorphism

The ability of pathogenic fungi to grow in a yeast-like form at $37^\text{C}$ inside the body and in a mold-like form at $24^\text{C}$ in the environment.

Zygomycota

A fungal phylum that forms sexual zygospores and asexual sporangiospores, with Rhizopus as an example.

Ascomycota

A fungal phylum that produces sexual ascospores and asexual conidiospores, with Penicillium and Aspergillus as examples.

Basidiomycota

A fungal phylum that produces sexual basidiospores and asexual conidiospores, with mushrooms as an example.

Systemic Mycosis

A fungal disease located deep within the body, typically originating in the lungs (e.g., histoplasmosis, coccidioidomycosis).

Subcutaneous Mycosis

A fungal disease located beneath the skin (e.g., sporotrichosis, also known as rose gardener's disease).

Cutaneous Mycosis

A fungal infection of the hair, skin, and nails caused by dermatophytes (keratin-digesting fungi, e.g., athlete's foot, ringworm).

Superficial Mycosis

A localized fungal infection of the hair shaft or superficial epidermal cells, prevalent in tropical climates (e.g., piedra).

Opportunistic Mycosis

A fungal infection caused by normal microbiota or environmental fungi in individuals with weakened immune systems (e.g., pneumocystis pneumonia in HIV/AIDS patients).

Lichen

A mutualistic association between an alga (which produces and secretes carbohydrates via photosynthesis) and a fungus (which anchors, protects, secretes organic acids, and absorbs water and nutrients).

Red Tide

A harmful algal bloom (HAB) caused by dinoflagellates due to nutrient runoff or sewage, which produces toxins leading to shellfish poisoning in humans.

Diatoms

Unicellular photosynthetic algae possessing cell walls made of silica ($\text{SiO}_2$) that produce domoic acid, a toxin causing neurological disease in humans and animals.

Trophozoite

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

Cyst (Protozoa)

The protective, dormant form of a protozoan that is usually infective and shed in host feces to survive in the environment.

Metamonada

A phylum of flagellated protozoa motile by two or more flagella, including Trichomonas vaginalis and Giardia duodenalis.

Euglenozoa

A group of flagellated blood protozoa (hemoflagellates) transmitted by blood-feeding insects, including Trypanosoma brucei gambiense and Trypanosoma cruzi.

Amoebozoa

Protozoa that move using pseudopodia, including Acanthamoeba (causing keratitis) and Entamoeba histolytica (causing amebic dysentery).

Apicomplexa

A phylum of obligate intracellular protozoan parasites non-motile in mature forms, possessing complex life cycles requiring multiple hosts (e.g., Plasmodium, Toxoplasma gondii).

Paroxysms

Periodic recurring attacks of chills and fever characteristic of malaria.

Ciliates

A group of protozoa that move using cilia, such as Balantidium coli, which causes severe dysentery and is transmitted via the fecal-oral route.

Dioecious

Organisms that have male and female reproductive organs located in separate individual organisms.

Monoecious

Organisms that contain both male and female reproductive organs within a single individual organism (hermaphroditic).

Nematodes

Roundworms and hookworms possessing a complete digestive system, mostly dioecious reproduction, and infective egg or larval stages.

Platyhelminthes

Flatworms, a phylum containing Trematodes (flukes) and Cestodes (tapeworms).

Trematodes

Flukes, a group of parasitic flatworms equipped with suckers for attachment (e.g., Schistosoma, Paragonimus).

Cestodes

Tapeworms, intestinal parasitic flatworms featuring a scolex for attachment and body segments called proglottids that produce eggs (e.g., Taenia solium, Taenia krabbei).