Eukaryotic Microbial Diversity and Characteristics

mycology

the study of fungi

vegetative structures

the main body parts of fungi (involved in growth and nutrient absorption)

spores

the reproductive structures of fungi

hyphae

tiny filaments that make up the body of multicellular fungi

mycelium

the hidden, main body of a fungus that often grows into their environment (like wood or dirt) and absorbs nutrients.

yeasts

Single celled fungi that reproduce by 'budding', use aerobic respiration in presence of oxygen, and can ferment when without O2 (e.g., Sacchromyces which makes alcohol and bread).

dimorphism

2 forms of growth: mold-like or yeast-like.

arthrospore

A fragment of a hypha that functions as a spore once fragmented.

chlamydospore

Thick-walled, asexual spore formed by rounding and enlargement of a hyphal cell, not easily dispersed but can survive extreme environmental stress.

sporangiospore

Asexual spores produced inside a sac-like structure called a sporangium that ruptures to release them.

conidiospore

Asexual spores produced externally on specialized hyphae called conidiophores, not enclosed in a sac.

blastospore

Asexual spore produced from 'budding' from the parent, typical in yeasts.

zygospores

Thick-walled, dormant spore formed from the fusion of two similar gametes.

ascospore

Spores formed in a saclike structure called ascus, formed in Ascomycota fungi (sac fungi).

basidiospore

Spores formed externally on a club-shaped structure called a basidium, associated with Basidiomycota fungi.

nutritional characteristics of fungi

1. They can live in an acidic environment. 2. They can live in low moisture. 3. They live on and decompose dead organic material (e.g., wood). 4. They can survive high osmotic pressure (e.g., sugar, salt).

Deuteromycota

Known for lacking a sexual reproduction stage, only reproduce asexually with conidiospores, and can cause athletes foot or ringworm.

Zygomycota

Now considered obsolete (DNA) and split into other groups like Mucoromycota and Zoopagomycota; parasitic fungi that feed on protozoa, nematodes, and arthropods.

Ascomycota

Largest and most diverse phylum of fungi that produce 'asci' sexually; examples include penicillium and truffles.

Basidiomycota

Reproduce sexually by forming basidiospores; includes very common mushrooms such as puffballs and portobello.

mycosis

fungal infection.

systemic mycosis

Throughout the body or in a deep organ, often in immunocompromised individuals.

subcutaneous mycosis

Beneath the skin, usually occurs through a wound.

cutaneous mycosis

Layers of skin/hair/nails which are rich in keratin, don't invade deeper, and are transmitted by direct contact or surfaces.

superficial

Outermost layer of skin/hair/nails.

planktonic algae

Free floating, mostly aquatic, photosynthetic organisms (algae).

dinoflagellates

Single-celled algae with characteristic two flagella that cause 'red tides' which are toxic.

euglenoids

Single celled, photosynthetic (but can engulf food particles), freshwater organisms that are important producers and consumers.

diatoms

Single celled algae, mostly aquatic, with a unique cell wall made of silica that accumulates as 'diatomaceous earth' after their death.

brown algae

Large, multicellular marine algae, such as kelp and rockweed, with 'algin' used as a thickening agent commercially.

red algae

Multicellular, marine algae with a cell wall that contains carrageenan (a commercial gelling agent) and agar.

green algae

Photosynthetic, mostly freshwater organisms that share many characteristics with land plants, including chlorophyll and cellulose cell walls.

thallus

The main body of a multicellular alga.

hold fast

The anchor of an alga.

stipe

The 'stalk' or 'stem'-like structure of an alga.

blades

The 'leaf' life structures of an alga.

blooms

Rapid, excessive growth of planktonic algae.

lichens

A symbiotic relationship between fungus and a photosynthetic partner (typically green algae or cyanobacteria), where the fungus provides structure and absorbs water and nutrients.

mutualism

A relationship in which both partners benefit.

crustose

Forming a thin, crust-like layer which cannot be removed without damaging the original surface.

foliose

Growing in a leaf-like pattern.

fruticose

Growing in a shrubby/bushy pattern.

slime molds

Fungus-like protists that live part of their life as independent cells and part as a large, moving blob.

Plasmodium (slime molds)

A giant, single-celled, blob-like mass of living cytoplasm that is acellular due to no cell walls separating nuclei.

protozoans

Single celled, animal-like protists that are mostly aquatic.

Sarcodina

Now placed in 'phylum Amoebozoa', these move and feed using 'pseudopodia' (false feet).

Entamoeba histolytica

Causes amoebic dysentery, transmitted via fecal-oral route.

Mastigophera

Protozoans which move with flagella.

Giardia lamblia

Causes diarrheal illness giardiasis, transmitted person-to-person or through contaminated water.

Trichomonas

Causes trichomoniasis, a sexual and urinary tract infection, exemplified by Trichomonas vaginalis.

Trypanosoma

Known for causing African sleeping sickness or Chagas disease.

Ciliata

Protozoans that move with cilia.

Balantidium coli

Often linked to contact with pigs, causing diarrhea, cramping, and sometimes dysentery-like symptoms.

Sporozoa

Non-motile protozoans.

Plasmodium

Transmitted by mosquitoes, parasites multiply in liver cells and then infect red blood cells, potentially leading to organ failure.

Toxoplasma

Causes toxoplasmosis

Transmission of Toxoplasma

Ingesting oocysts from cat feces, eating undercooked meat, congenital transmission (mother to fetus)

Toxoplasma gondii

Also known as 'multiple fission'

Schizogony

Type of asexual reproduction common in protozoans; one parent cell divides nucleus multiple times before cytoplasm splits and multiple daughter cells are produced simultaneously.

Cyst

Dormant, protective stages in life cycle of many protozoans; helps them survive harsh environments.

Helminthes

Multicellular, parasitic worms that cause many diseases and are not microscopic.

Dioecious

Having both male and female organisms separately.

Hermaphroditic

Individuals containing both male and female reproductive organs.

Definitive host

The host in which parasite reaches sexual maturity and reproduces.

Intermediate host

The host in which parasite undergoes development or asexual stages but does not reproduce.

Platyhelminthes

Flatworms that are soft-bodied, unsegmented, with many free-living and some parasitic; have an incomplete digestive system (one opening).

Trematodes

Parasitic flatworms that require at least one intermediate host (often snails) and a definitive host (often mammals).

Paragonimus

Lung flukes that infect lungs of mammals; transmission through raw or undercooked freshwater crustaceans.

Schistosoma

Genus of blood flukes that live in blood vessels and cause schistosomiasis; larvae are released into water by snails and burrow into skin.

Cestodes

Parasitic flatworms that live in intestines of vertebrate hosts and absorb nutrients directly through their skin.

Scolex

The head of a tapeworm that has suckers or hooks to attach to the intestinal wall.

Proglottids

Segments of a tapeworm.

Taenia

Beef or pork tapeworm; transmission through undercooked meat; larvae form cysts in the muscles of cattle.

Echinococcus

Tiny tapeworms that infect canines and then humans through ingestion of eggs; form hydatid cysts in organs.

Nematodes

Roundworms that are unsegmented with a complete digestive tract; many are free-living but some are parasitic.

Enterobius

Pinworm; one of the most common parasitic infections in children; fecal-oral transmission.

Necator

Hookworm that infects human intestines, feeding on blood and causing anemia and weakness.

Trichinella

Found in pork and bear meat; causes intestinal pain and migrates to muscles, forming cysts.

Arthropods

Diverse group of segmented, invertebrate animals with jointed appendages (legs, antennae, etc.).

Vectors

Living organisms that transmit a pathogen from one host to another.

Arachnida

Class of arthropods that includes spiders, ticks, and mites.

Crustacea

Aquatic arthropods with hard exoskeletons, including crabs, crayfish, and lobsters.

Chilopoda

Class of arthropods that includes centipedes, which have 15-177 pairs of legs.

Diplopoda

Class of arthropods that includes millipedes, which have 30-300 pairs of legs and are important decomposers.

Insecta

Largest class within Arthropoda, containing insects; characterized by 3 segments and 6 legs; common vectors for diseases.