Investigating Protists Lab

Vocabulary flashcards covering the characteristics, classification, ecological roles, and pathogenic examples of protists based on the lecture notes.

Kingdom Protista

An artificial category for eukaryotic life forms that do not fit into other eukaryotic kingdoms, most of which are microscopic and unicellular organisms.

Endosymbiotic Theory

The theory that infoldings in the plasma membrane of an ancestral prokaryote gave rise to the nucleus and endoplasmic reticulum, while the consumption of aerobic and photosynthetic bacteria evolved into mitochondria and chloroplasts.

Phagocytosis

A process in which some heterotrophic protists ingest particles by engulfing a food particle with the cell membrane to form an intracellular membranous sac or vesicle called a food vacuole.

Saprobes

Subtypes of heterotrophs that consume organic materials by absorbing nutrients from dead organisms or their organic wastes.

Taxis

A movement toward or away from a stimulus, such as phototaxis, which involves a light-sensing organ and a flagellum.

Pseudopodia

Cytoplasmic extensions, meaning "false feet," that certain protists like $Amoeba$ use to anchor themselves to a substrate and pull themselves forward.

Protozoa

An informal classification for animal-like protists that are motile, ingest food, and lack a cell wall, such as members of the genera $Amoeba$ and $Paramecium$.

Algae

A group of photosynthetic protists that usually possess a cell wall and chloroplasts, ranging from microscopic forms to kelp over $200\,m$ in length.

Fungi-like protists

An informal classification for protists that act as decomposers, usually have a cell wall, and are typically non-motile.

Phytoplankton

Microscopic producers suspended in water that are primarily composed of protists and some bacteria.

Zooplankton

Microscopic organisms suspended in water that are animal-like, some of which are protists.

$$Zooxanthellae$$

A type of dinoflagellate that lives in a symbiotic relationship within coral polyps, providing nutrients for energy to secrete calcium carbonate skeletons.

Coral bleaching

A process in which corals lose their algal pigments and eventually die because they have lost their dinoflagellate symbionts.

Phycoerythrin

A red accessory pigment that predominates in the chloroplasts of red algae belonging to Phylum $Rhodophyta$.

Agar

A substance originating from the cell wall of $Rhodophyta$ used for gel capsules, cosmetics, and as a base for laboratory culture media.

Carrageenan

A stabilizer for paints, cosmetics, dairy products, and toothpaste that originates from the cell walls of $Rhodophyta$.

Pneumatocysts

Gas-filled air bladders produced by certain brown algae, such as $Fucus\,vesiculosus$, used to increase buoyancy.

Diatoms

A major group of microscopic algae with glassy silica-based shells that generate approximately $20\%\text{ to }50\%$ of the oxygen produced on Earth annually.

Contractile vacuoles

Organelles in protists like $Paramecium$ that collect and expel unwanted water to maintain balance in a hypotonic environment.

Oral groove

A structure in $Paramecium$ lined with cilia that facilitates the movement of food particles toward the cell for ingestion into food vacuoles.

Eyespot

A special pigmented organelle in $Euglena$ that shields a light detector associated with the flagellum used for sensing light.

$$Acetabularia$$

A microscopic single-celled green alga used by Hämmerling in the $1930s\text{ to }1950s$ to demonstrate important facts about hereditary information in the cell.

$$P.\,falciparum$$

A parasitic protist that stains purple and is the causative agent of malaria in humans.

$$Trypanosomes$$

Protist parasites that serve as the causative agents for African sleeping sickness.