Chapter 23: Protists

Question 1

Biological Carbon Pump

Answer 1

process by which inorganic carbon is fixed by photosynthetic species that then die and fall to the sea floor where they cannot be reached by saprobes and their carbon dioxide consumption cannot be returned to the atmosphere

Question 2

Bioluminescence

Answer 2

generation and emission of light by an organism, as in dinoflagellates

Question 3

Contractile Vacuole

Answer 3

vesicle that fills with water (as it enters the cell by osmosis) and then contracts to squeeze water from the cell; an osmoregulatory vesicle

Question 4

Cytoplasmic Streaming

Answer 4

movement to cytoplasm into an extended pseudopod such that the entire cell is transported to the site of the pseudopod

Question 5

Endosymbiosis

Answer 5

engulfment of one cell within another such that the engulfed cell survives, and both cell benefit: the process responsible for the evolution of mitochondria and chloroplasts in eukaryotes

Question 6

Endosymbiotic Theory

Answer 6

theory that states that eukaryotes may have been a product of one cell engulfing another, one living within another, and evolving over time until the separate cells were no longer recognizable as such

Question 7

Hydrogenosome

Answer 7

organelle carried by parabasalids (Excavata) that functions anaerobically and outputs hydrogen gas as a byproduct; likely evolved from mitochondria

Question 8

Kinetoplast

Answer 8

mass of DNA carried within the single, oversized mitochondrion, characteristic of kinetoplastids (phylum: Euglenozoa)

Question 9

Mitosome

Answer 9

nonfunctional organelle carried in the cells of diplomonads (Excavata) that likely evolved from a mitochondrion

Question 10

Mixotroph

Answer 10

organism that can obtain nutrition by autotrophic or heterotrophic means, usually facultatively

Question 11

Pellicle

Answer 11

outer cell covering composed of interlocking protein strips that function like a flexible coat of armor, preventing cells from being torn or pierced without compromising their range of motion

Question 12

Phagolysosome

Answer 12

cellular body formed by the union of a phagosome containing the ingested particle with a lysosome that contains hydrolytic enzymes

Question 13

Plankton

Answer 13

diverse group of mostly microscope organisms that drift in marine and freshwater systems and serve as a food source for larger aquatic organisms

Question 14

Plastid

Answer 14

one of a group of related organelles in plant cells that are involved in the storage of starches, fats, proteins, and pigments

Question 15

Raphe

Answer 15

slit in the silica shell of diatoms through which the protist secretes a stream of mucopolysaccharides for locomotion and attachment to substrates

Question 16

Test

Answer 16

porous shell of a foram that is built from various organic materials and typically hardened with calcium carbonate