Protists, Bacteria, and Archaea Flashcards

Flashcards on Protists, Bacteria, and Archaea based on lecture notes.

Prokaryotes

Cells that lack a membrane-bound nucleus and membrane-bound organelles. DNA is arranged in a ring. Includes Domains Bacteria and Archaea.

Peptidoglycan

A substance unique to bacteria cell walls.

Flagellin

The protein that comprises bacterial flagella.

Cyanobacteria

Bacteria that use Photosystems I & II, have chlorophyll a in scattered thylakoid membranes (no chloroplasts), and have heterocysts to fix nitrogen.

Heterocysts

Specialized cells in cyanobacteria that can fix nitrogen from the atmosphere.

Taxonomic Hierarchy

Domain, Kingdom, Phylum/Division, Class, Order, Family, Genus, Species (Epithet)

Protists

Eukaryotic organisms, mostly unicellular, that can be animal-like, plant-like, or fungus-like.

Convergent Evolution

The independent evolution of similar features in different lineages. An example is fungus-like protists occupying similar niches to fungi.

Mixotrophic

An organism that can be both autotrophic and heterotrophic.

Excavata

A supergroup/clade of protists, some with an 'excavated' groove on one side of the cell body.

Diplomonads

Members of Excavata that lack plastids, have mitosomes, and use anaerobic pathways for energy. Many are parasitic (e.g., Giardia).

Giardia lamblia

A diplomonad; the causative agent of 'beaver fever', acquired through fecal-contaminated water.

Parabasalids

Members of Excavata that have hydrogenosomes and generate energy anaerobically, releasing hydrogen gas as a byproduct. Includes Trichomonas vaginalis.

Trichomonas vaginalis

A parabasalid; a common inhabitant of the human vagina which can cause infection if the vaginal pH is disturbed.

Euglenozoa

Members of Excavata that have flagella containing a spiral or crystalline rod-like structure. Includes predatory heterotrophs, photosynthetic autotrophs, mixotrophs, and parasites.

Kinetoplastida

A phylum within Euglenozoa characterized by a large single mitochondrion containing a kinetoplast (organized mass of DNA).

Trypanosoma brucei

A kinetoplastid; the causative agent of sleeping sickness, transmitted via the bite of the tsetse fly.

Euglenophyta

A phylum within Euglenozoa characterized. Can be mixotrophic; Has chlorophylls A & B, no cell wall, has pellicle, stigma, stores carbohydrate as paramylon, pyrenoid-structure.

Pellicle

A flexible protein layer that maintains the cell shape in euglenoids.

Stigma

A light-sensitive organelle in euglenoids.

Paramylon

The carbohydrate storage form in euglenoids.

SAR Clade

Stramenopiles, Alveolates, and Rhizarians.

Stramenopiles

A kingdom within Chromalveolata characterized by hair-like projections on their flagella. Contains both autotrophs and heterotrophs.

Diatoms

Unicellular algae with unique glass-like walls made of hydrated silica (Phylum Bacillariophyta).

Diatomaceous Earth

Accumulation of diatom walls in sediment, used in filters and toothpaste.

Chrysophyta

Known as the Golden Algae; Have Chlorophylls A & C, store carbohydrate as laminarin, can be mixotrophic.

Phaeophyta

Known as the Brown Algae. Are multicellular, one of the 'seaweeds,' and contain algin in their cell walls.

Algin

A substance found in the cell walls of brown algae, used as a thickening agent.

Oomycota

Commonly called water molds, white rusts, and downy mildews. Are heterotrophic with cellulose cell walls.

Alveolata

A kingdom within Chromalveolata characterized by membrane-enclosed sacs (alveoli) under their plasma membranes.

Dinoflagellata

A phylum within Alveolata characterized by cells with reinforced plates of cellulose and two flagella. They can also cause 'red tides'.

Trichocysts

Mini harpoons in dinoflagellates.

Apicomplexa

Parasites of animals named from the apical complex they use to penetrate host cells. Includes Plasmodium.

Plasmodium

The causative agent of malaria, transmitted via the bite of the Anopheles female mosquito.

Ciliophora

A phylum within Alveolata characterized by the use of cilia for locomotion and unique with 2 types of nuclei. Includes Paramecium.

Rhizaria

A supergroup/clade of protists with movement via axopodia (their pseudopodia). Has an internal skeleton comprised of silica.

Radiolaria

A phylum within Rhizaria that have axopodia.

Foraminifera

A phylum within Rhizaria with shells (called tests) hardened with calcium carbonate.

Cercozoa

A phylum within Rhizaria with thread-like pseudopodia.

Archaeplastida

A supergroup/clade that includes red algae, green algae, and land plants.

Rhodophyta

Commonly known as 'Red Algae'; possess phycoerythrin, which gives them a reddish color Has chlorophylls A & D, stores carbohydrate as floridian starch. Agar comes from here.

Phycoerythrin

The pigment that gives red algae their reddish color.

Chlorophyta

Commonly known as 'Green Algae.' They have Chlorophylls A & B.

Unikonta

A supergroup/clade that includes amoebozoans and opisthokonts (animals, fungi, and related protists).

Amoebozoa

A kingdom within Unikonta characterized by lobe-shaped or tube-shaped pseudopodia.

Myxogastria

Common name 'Plasmodial Slime Molds'; a phylum within Amoebozoa. They progress from a large coenocytic mass called a plasmodium.

Dictyostelida

Common name 'Cellular Slime Molds'; a phylum within Amoebozoa. Feeding stage consists of solitary cells.

Gymnamoeba

Known as Tubulinids; a phylum within Amoebozoa found in soil, fresh, and marine waters.

Entamoeba

A phylum within Amoebozoa; E. histolytica is the causative agent of amoeabic dysentery.

E. histolytica

Causative agent of amoeabic dysentery, spread via contaminated drinking water.