Protists and Slime Molds – Vocabulary (Chapter 1-6)

Protists

Eukaryotic, nucleus-containing organisms that are usually unicellular, though some are multicellular or colonial; diverse in nutrition (autotrophs, heterotrophs, or mixotrophs).

Eukaryote

Organisms whose cells contain a nucleus and membrane-bound organelles.

Prokaryote

Organisms that lack a nucleus and membrane-bound organelles (examples: bacteria and archaea).

Nucleus

Membrane-bound organelle that houses genetic material in eukaryotic cells.

Membrane-bound organelles

Internal cell structures enclosed by membranes (e.g., mitochondria, chloroplasts) found in eukaryotes.

Heterotroph

Organism that obtains carbon/energy by consuming or absorbing organic matter from outside its body.

Autotroph

Organism capable of producing its own food via photosynthesis (self-feeding).

Mixotroph

Organism that can use both autotrophy and heterotrophy to acquire energy and nutrients.

Fungus-like protists

Protists that feed by external digestion and absorption; often decomposers, including slime molds.

Animal-like protists

Protists that move and feed like animals; typically heterotrophic (protozoans).

Plant-like protists (algae)

Autotrophic protists capable of photosynthesis; diverse group including diatoms and green algae.

Amoebas

Protists that move and feed using pseudopodia (temporary cytoplasmic extensions).

Pseudopodia

Temporary projections of cytoplasm used for movement and feeding.

Lobed pseudopodia

Broad, lobe-shaped pseudopodia used by certain amoebas (sarcodines) for movement and feeding.

Sarcodina

Group of amoeboid protists characterized by lobed pseudopodia.

Axopodia

Thin, spike-like pseudopodia used for movement and prey capture in some protists.

Actinopoda

Protist group with axopodia; often have silica or other mineral skeletons (radiolarians and heliozoans).

Flagellates

Protists that move using one or more flagella; examples include Trypanosoma.

Flagellum

Whip-like tail used for locomotion in flagellated cells (plural: flagella).

Paramecium

A ciliate protist that uses numerous cilia for movement and feeding.

Cilia

Hair-like projections on the surface of some protists used for movement and feeding.

Ciliates

Protists with many cilia; example: Paramecium.

Diatoms

Plant-like protists with silica cell walls; contain chlorophylls a and c; limited locomotion; major oxygen producers.

Chlorophylls a and c

Photosynthetic pigments found in diatoms and some algae (a and c; different from land plants).

Silica cell wall

Rigid silica-based outer shell of diatoms.

Green algae (Chlorophyta)

Plant-like autotrophic protists with chlorophylls a and b; cellulose cell walls; often flagellated.

Chlorophylls a and b

Photosynthetic pigments that capture light energy in green algae and plants.

Dinoflagellates

Mixotrophic or autotrophic protists with two flagella; often bioluminescent and can cause red tides.

Bioluminescence

Emission of light by living organisms, such as some dinoflagellates.