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44 terms

Chapter 25: Protists

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Protists
Single-celled or simple multicellular eukaryotic organisms that generally do not fit in any other kingdom
Binary fission
A form of reproduction where one protist cell splits into two identical cells
Multiple fission
A form of reproduction that produces more than two offspring
Conjugation
Where two individuals join and exchange genetic material stored in a small second nucleus
Pseudopodia
Large, rounded cytoplasmic extensions that function both in movement and feeding
Amoeboid movement
A method of movement involving the creation of pseudopodia
Test
A protective covering used by some protists
Cilia
Short, hairlike cytoplasmic projections that line the cell membrane
Pellicle
A clear, elastic layer of protien that surrounds the cell membrane of ciliates
Oral groove
A funnel-like depression in a pellicle, leads to the mouth pore
Mouth pore
Through which food is swept into a ciliate's gullet
Gullet
Forms food vacuoles that move through a ciliate's cytoplasm
Anal pore
Expels undigested materials
Contractile vacuoles
Saclike organelles that expand to collect excess water and contract to squeeze the water out of the cell
Macronucleus
Contains multiple copies of DNA that direct the cell's metabolism and development
Micronucleus
Used in the exchange of genetic material during conjugation
Flagella
Long, whiplike structures that are made up of microtubules and used for movement
Algae
Autotrophic protists that have chloroplasts and produce their food through photosynthesis
Gametangia
Single-celled gamete chambers in which an alga's gametes are formed
Phytoplankton
Free-living aquatic organisms that are at the base of most marine and freshwater food chains (most unicellular algae are these)
Thallus
The plantlike body portion of a seaweed (usually has haploid cells)
Accessory pigments
Pigments that capture light energy and transfer it to chlorophyll
Diatoms
Unicellular protists that have double shells which contain silicon dioxide
Shells
The cell walls of diatoms which have two parts (like a box and lid) called valves made of silicon dioxide
Bioluminescence
The production of light by means of a chemical reaction in an organism
Red tide
Where dinoflagellate populations explode and they turn the water brownish red
Euglenoids
Flagellated unicellular algae that are both animal-like and plantlike
Fruiting body
A funguslike, spore-bearing structure that funguslike protists produce
Water mold
A funguslike protist composed of branching filaments of cells
Plasmodial slime molds
A funguslike protist that has ameboid cells, flagellated cells, and a plasmodial feeding stage in its life cycle
Cellular slime molds
A funguslike protist that lives as an individual haploid amoeboid cell which gathers with other such cells in a pseudoplasmodium when nutrients are scarce
Algal blooms
A vast increase in the concentration of diatoms and other photosynthetic protists which can be caused by high water temperatures or nutrient concentrations
Chemotaxis
The movement toward or away from a chemical stimuluslike movement towards food or away from toxins
Alginate
A polysccharide used in cosmetics, in various drugs, as a stabilizer in ice cream and salad dressings, in textiles, water-soluble medical dressings, for burns, and in inks, which is found in the cell walls of brown algae
Carregeenan
A sticky substance sometimes found on the cell walls of red algae
Agar
A polysccaride used in scientific research to culture microbes, and also in canned food and bakery items that is found on the cell walls of red algae
Diatomaceous earth
A layer of material at the bottom of lakes and oceans formed when diatoms die and their shells accumulate, which is used in detergents, paint removers, toothpaste, and sometimes in in fliters, or as a natural insecticide
Malaria
A disease caused by apicomplexians caracterized by severe chills, headache, fever, and fatigue
Sporozoites
Plasmodium cells that enter a human's bloodstream with a mosquito bite and infect the liver
Merozoites
New Plasmodium cells formed in the liver and infect human red blood cells
Gametocytes
Merozoites that develop the sexual forms of the parasite which are ingested by a mosquito when it bites an infected person and forms gametes
Giardiasis
An illness caused by Giardia lamblia that is characterized by severe diarrhea and intestinal cramps
Cryptosporidiosis
An illness caused mostly by Cryptosporidium parvum that is characterized by diarrhea and is resistant to chlorine disinfectants due to the protist's outer shell
Trichomoniasis
A disease caused by Trichomonas vaginalis and is spread by sexual contact (one of the most commmon sexually transmitted diseases)