Eukaryotic Diversity: Unicellular to Multicellular Organisms

Eukaryotic microbes

Extremely diverse organisms with specialized structures.

Protozoa

Unicellular, animal-like, heterotrophic eukaryotes.

Helminths

Parasitic worms, often affecting humans.

Fungi

Eukaryotic organisms, including molds and yeasts.

Algae

Plant-like protists, can be unicellular or multicellular.

Lichens

Symbiotic relationship between fungi and algae.

Protists

Eukaryotes that are not plants, animals, or fungi.

Plankton

Microorganisms drifting in water, moved by currents.

Zooplankton

Motile, non-photosynthetic plankton.

Phytoplankton

Photosynthetic microorganisms in aquatic environments.

Trophozoites

Feeding and growth stage of protozoa.

Cysts

Encapsulated stage for protection in harsh environments.

Asexual reproduction

Reproduction without gamete fusion, e.g., binary fission.

Sexual reproduction

Involves fusion of haploid gametes, syngamy.

Plasmalemma

Membrane surrounding protozoan cells.

Pellicle

Protein bands providing rigidity to protozoan membranes.

Cytostome

Structure for nutrient uptake in protozoa.

Holozoic protists

Take in whole food particles.

Saprozoic protists

Absorb smaller nutrient molecules.

Cytoproct

Exocytosis structure for waste removal.

Flagella

Whip-like structures for protozoan locomotion.

Cilia

Hair-like structures for movement and feeding.

Pseudopodia

Cytoplasmic extensions for attachment and movement.

Contractile vacuoles

Regulate osmotic pressure in protozoa.

Kinetoplastid DNA

DNA bundles associated with flagella in some protozoa.

Hydrogenosomes

Organelles producing ATP without oxygen.

Polyphyletic

Groups derived from multiple ancestral sources.

Amoebozoa

Group of protists with amoeba-like movement.

Entamoeba histolytica

Causative agent of amoebic dysentery.

Naegleria fowleri

Agent of amoebic meningoencephalitis.

Acanthamoeba spp.

Causes keratitis in contact lens users.

Cellular slime molds

Aggregate into mobile slugs to reproduce.

Plasmodial slime molds

Large cells with multiple nuclei, form stalks.

Dictyostelium discoideum

Example of cellular slime mold.

Fuligo septica

Example of plasmodial slime mold.

Excavata

Group with a depression on cell surface.

Chromalveolata

Group characterized by plastids containing pigments.

Apicomplexans

Intracellular parasites with an apical complex.

Ciliates

Organisms using cilia for movement and feeding.

Oomycetes

Water molds resembling fungi, with cellulose walls.

Plasmodium spp.

Genus causing malaria, infects multiple hosts.

Cryptosporidium parvum

Contaminates water, causes intestinal symptoms.

Babesia microti

Transmitted by ticks, causes babesiosis.

Toxoplasma gondii

Causes toxoplasmosis, transmitted via cat feces.

Balantidium coli

Only pathogenic ciliate affecting humans.

Paramecium

Commonly studied ciliate in laboratories.

Conjugation

Reproductive process in ciliates.

Fornicata

Excavata group lacking mitochondria, possessing flagella.

Giardia lamblia

Causes giardiasis, spread via contaminated water.

Parabasalia

Endosymbionts in termites, modified mitochondria present.

Trichomonas vaginalis

Causes trichomoniasis, a sexually transmitted infection.

Euglenozoa

Includes photo and non-photosynthetic organisms.

Trypanosoma

Genus causing African sleeping sickness and Chagas disease.

Helminths

Multicellular parasites with complex life cycles.

Nematoda

Phylum of roundworms, includes many parasites.

Platyhelminthes

Phylum of flatworms, includes flukes and tapeworms.

Monoecious

Organisms with both male and female reproductive organs.

Dioecious

Organisms with distinct male or female sexes.

Ascaris lumbricoides

Largest roundworm infecting humans.

Enterobius vermicularis

Commonly known as pinworm, infects humans.

Toxocara spp.

Common in dogs and cats, can infect humans.

Schizogeny

Asexual reproduction process in Apicomplexans.

Helminths

Parasitic worms including tapeworms and flukes.

Cestodes

Segmented flatworms known as tapeworms.

Trematodes

Nonsegmented flatworms with oral suckers.

Proglottid

Segment of a tapeworm containing reproductive structures.

Scolex

Head region of a tapeworm with suckers/hooks.

Taenia spp.

Beef and pork tapeworms from contaminated meat.

Mycoses

Illnesses caused by fungal infections.

Hyphae

Filamentous structures forming the body of molds.

Mycelium

Mass of hyphae forming the main body of fungi.

Septate hyphae

Hyphae with walls separating individual cells.

Coenocytic hyphae

Hyphae without walls between cells.

Pseudohyphae

Budding yeast cells that resemble hyphae.

Chitin

Polysaccharide in fungal cell walls.

Ergosterol

Sterol found in fungal cell membranes.

Dimorphic fungi

Fungi that can exist as yeast or mold.

Ascomycota

Fungal phylum including pathogens and food producers.

Ascospores

Sexual spores produced by Ascomycota.

Conidia

Asexual spores produced by Ascomycota.

Candida albicans

Yeast causing opportunistic infections like thrush.

Basidiomycota

Fungal phylum producing basidiospores.

Amanita phalloides

Poisonous mushroom known as the death cap.

Microsporidia

Unicellular parasites lacking mitochondria.

Zygomycota

Fungal phylum with coenocytic hyphae.

Zygospores

Sexual spores formed by Zygomycota.

Dinoflagellates

Algae with two flagella and cellulose armor.

Stramenopiles

Algae group including diatoms and brown algae.

Diatoms

Algae with silica frustules, major oxygen producers.

Red algae

Algae with agar or carrageenan in cell walls.

Prototheca spp.

Algae causing rare skin infections.

Lichens

Symbiotic association of fungi and algae.

Crustose lichen

Flat, crust-like lichen morphology.

Foliose lichen

Leafy, lobed lichen morphology.

Fruticose lichen

Shrub-like, branching lichen morphology.