Microbiology Lecture Notes: Protists, Lichens, Fungi, Helminths, and Viruses

Flashcards covering the taxonomy and characteristics of protists, fungi, lichens, helminths, viruses, viroids, and prions based on the lecture on biological diversity.

Lichen

A unique organism that colonization habitats unsuitable for either fungi or algae alone, resulting from a symbiotic relationship between a fungus (Ascomycota or Basidiomycota) and a photosynthetic partner (algae or cyanobacteria).

Crustose

One of the three types of lichens mentioned that grows on surfaces, often seen as a crust-like layer on rocks.

Foliose

A type of lichen that looks like a leaf, though it is neither a leaf nor a fungus alone.

Fruticose

A type of lichen characterized by more strand-like or branching structures.

Bio indicators

Organisms like lichens that serve as indicators of air quality and the overall health of an environment.

Saprozoic

A characteristic of fungi meaning they are decomposers that break down large quantities of organic matter into smaller entities for nutrient recycling.

Mycosis

A fungal infection that can be focal (at a specific point) or systemic if the infection or spores spread throughout the body.

Hyphae

Complex multicellular or multinucleated networks of interwoven filamentous structures that are a characteristic anatomical feature of fungi.

Mycelium

The whole bunch or network of hyphae together.

Septate hyphae

Hyphae that contain cross-walls or septa, dividing the filaments into individual rooms or compartments.

Aseptate hyphae

Hyphae without segmentations or walls, also known as coenocytic hyphae, allowing for a continuous flow of nutrients.

Chitin

The chemical substance that composes the cell wall of a fungus.

Phylum Microsporidia

A group of unicellular, non-motile obligate intracellular parasites that use a unique polar tube (harpoon) for infection and lack typical hyphae.

Phylum Zygomycota

Multicellular fungi with aseptic hyphae, such as Rhizopus stolonifer (red bread mold), that typically inhabit soil and terrestrial environments.

Phylum Basidiomycota

Commonly known as club fungi, this phylum includes mushrooms, puffballs, stink horns, and the poisonous Amanita phalloides (death cap).

Phylum Ascomycota

The largest and most diverse fungal phylum, featuring truffles, morels, cup fungi, Saccharomyces cerevisiae (baker's yeast), and Penicillium.

Platyhelminthes

A group of parasitic worms known as flatworms, which include flukes (trematodes) and tapeworms (cestodes).

Nematoda

Parasitic worms known as roundworms, characterized by unsegmented cylindrical bodies and a unique whip-like movement.

Pinworm

The most common parasitic worm in the United States.

Ascaris lumbricoides

The most common parasitic worm worldwide.

Scolex

The specialized attachment structure on a tapeworm that includes suckers and hooks to anchor the parasite to the host.

Proglottids

The hermaphroditic segments of a tapeworm, each containing both male and female reproductive systems (testes and ovaries).

Taenia saginata

The specific type of tapeworm associated with beef cattle.

Taenia solium

The specific type of tapeworm associated with pork.

Virion

Another term for a virus, defined as an obligate intracellular pathogen.

Fomites

Non-living objects such as desks, backpacks, or pencils that can transmit infectious particles.

Lytic cycle

The viral life cycle that is pathogenic and involves exponential growth, reproducing thousands or millions of virions from one host cell.

Lysogenic cycle

The viral life cycle where the virus integrates into the host DNA and remains dormant or latent.

Positive single-stranded RNA

A type of viral RNA that works directly as mRNA and can be immediately translated by host ribosomes into protein.

Reverse transcriptase

A unique enzyme found in retroviruses like HIV that transcribes RNA back into DNA, a process not found in any living organism.

Viroids

Small, single-stranded RNA molecules ($220$ to $380$ nucleotides) that self-replicate without a protein coat, typically infecting plants.

Prion

A misfolded infectious protein enriched in beta sheets that induces normal proteins to misfold, leading to fatal, degenerative spongy holes in the brain.

Spongiform encephalopathy

A condition caused by prions characterized by sponge-like holes in the brain, such as Mad Cow Disease or Creutzfeldt-Jakob disease.