Chapter 23: Protists

A comprehensive set of vocabulary flashcards covering key concepts in the study of protists, their characteristics, metabolism, reproduction, and ecological roles.

Protists

Organisms classified in the kingdom Protista, typically unicellular or simple multicellular eukaryotes.

Eukaryotic Cells

Cells that contain a nucleus and membrane-bound organelles.

Nuclear Envelope

A double membrane that surrounds and protects the nucleus.

Mitochondria

Membrane-bound organelles where cellular respiration occurs, producing energy.

Cytoskeleton

A network of fibers that organizes cell structure and activities.

Flagella

Long, whip-like structures that aid in the movement of cells.

Cilia

Short, hair-like structures that also assist in cell movement.

Endosymbiosis

A theory that explains the origin of eukaryotic cells through symbiotic relationships.

Chloroplasts

Organelles responsible for photosynthesis in plants and some protists.

Amoebozoa

A group of protists characterized by amoeboid movement and phagocytosis.

Archaeplastida

Supergroup that includes plants and algae, characterized by chloroplasts derived from cyanobacteria.

Excavata

A diverse group of protists, many of which have flagella and lack conventional mitochondria.

Mixotrophs

Organisms that can use both photosynthesis and heterotrophic nutrition.

Phagocytosis

The process by which a cell engulfs particles or other cells.

Saprobes

Heterotrophic organisms that obtain nutrients from decaying organic matter.

Symbionts

Organisms that live in close association with another organism, which may be mutualistic, commensal, or parasitic.

Alternation of Generations

A reproductive cycle in which organisms alternate between haploid and diploid stages.

Plasmodium

A genus of protists that cause malaria in humans.

Trypanosoma

A genus of protists that cause sleeping sickness, transmitted by the tsetse fly.

Diatoms

Unicellular algae with silica cell walls, significant primary producers in aquatic ecosystems.

Brown Algae

Multicellular, mostly marine algae that include seaweeds; important producers in coastal environments.

Dinoflagellates

Unicellular protists with flagella; some species are bioluminescent or toxic.

Morphological Characteristics

Physical attributes used to categorize and distinguish between different organisms.

Motility

The ability of an organism to move independently using metabolic energy.

Asexual Reproduction

Reproduction that does not involve the fusion of gametes; includes binary fission and budding.

Sexual Reproduction

Reproduction involving the combination of genetic material from two parents.

Euglenozoans

A group of flagellated protists characterized by unique mitochondria and diverse nutritional modes.

Gymnamoebas

Free-living amoebas found in various habitats, feeding on bacteria and other protists.

Entamoebas

Pathogenic amoebas that can infect human guts and cause diseases.

Ciliates

A group of protists characterized by the presence of cilia, used for movement and feeding.

Apicomplexans

A group of parasitic protists that typically have complex life cycles involving multiple hosts.

Alveolates

Group of protists that possess membrane-bound sacs (alveoli) beneath the plasma membrane.

Cell Differentiation

The process by which generic cells change into specialized cells.

Photosynthesis

The process through which green plants and some protists use sunlight to synthesize nutrients.

Endosymbiotic Theory

The theory that eukaryotic cells arose from symbiotic relationships between prokaryotic cells.

Microtubules

Cylindrical structures that are part of the cytoskeleton and are involved in cell shape and movement.

Parabasalids

A group of flagellated protists that are typically anaerobic and often symbiotic.

Giardia intestinalis

A parasite that causes intestinal discomfort, often found in contaminated water.

Chlorophytes

A class of green algae closely related to land plants.

Red Algae

Marine algae that have red pigments and can be multicellular.

Phytoplankton

Photosynthetic microorganisms that float near the surface of water.

Larval Stages

The juvenile form of an organism that undergoes development into adulthood.

Flagellar Motility

Movement mechanism in some protists driven by one or more flagella.

Cell Junctions

Structures that facilitate communication and adhesion between cells.

Environmental Changes

Conditions such as temperature, nutrient availability that can influence protist life cycles.

Human Health Impact

The influence of protist diseases on human health, including infections and epidemics.