BSC 1011 Brooks Unit 3 Exam Review
Questions And Complete Answers
Which is the most primitive Parazoan? - ANSWER Placozoa
Asconoid - ANSWER Simplest form of sponges, with canals leading directly from the
outside to the interior (Sac)
Syconoid + Leuconoid - ANSWER Sponge body plans with more layers
Porocytes - ANSWER (Outer) Tubular cells that allow water to flow from the outside of
the sponge to its central cavity
Myocytes - ANSWER (Outer) muscle cells
Spicules - ANSWER (Middle) small, spike shaped particles of calcium carbonate or
silicon dioxide that make up the skeleton of some sponges
Spongin - ANSWER (Middle) Flexible protein material that make up the skeleton of some
sponges.
Amoebocytes - ANSWER Cells that create other cell types
Collencytes - ANSWER Used for structural support, neuron-like
Choanocytes - ANSWER Collar cells that line the body cavity and have flagella that
circulate water in sponges (similar morphology to choanoflagelletic protists)
Class Calcarea - ANSWER calcium carbonate spicules
Class Hexactinellida - ANSWER glass sponges
Class Demospongiae - ANSWER Most sponges today are in this class
Most diverse class
Class Sclerospongiae - ANSWER coralline sponges
Metagenesis (cnidaria) - ANSWER Alternation of generations-like process between
polyp and medusa
Cnidae - ANSWER Capsule-like organelles that are contained in cnidocytes.
Nematocysts - ANSWER Cnidae type:
stinging cells
Spirocysts - ANSWER Cnidae type:
, Used for adherence
Only in Anthozoans
Ptychocysts - ANSWER Cnidae type:
Substrate used to construct tube for burrowing sea anemones.
"Nerve Net" - ANSWER Of cnidarians, a mesh of interacting neurons with no central
control organ
Class Hydrozoa - ANSWER Polyp stage dominant
Polymorphism
What type of mesoglea exists in Class Hydrozoa? - ANSWER Acellular
Where are the Cnidae located in Class Hydrozoa? - ANSWER Epidermis
Polymorphism - ANSWER The coexistence of two or more distinct forms in the same
population.
Gastrozooid - ANSWER feeding polyp
Gonozooid (Gonangium) - ANSWER reproductive polyp
Dactylzooid - ANSWER Contain nematocysts
Skeletozooid - ANSWER Produce chitinous structure
Hydra - ANSWER No metagenesis because of freshwater habitat
Obelia medusa - ANSWER Hydra-Like
Physalia - ANSWER Portuguese man-of-war
"a floating, polymorphic colony"
Class Scyphozoa - ANSWER medusa stage dominant
"Scyphomedusae" large
What type of mesoglea exists in Class Scyphozoa? - ANSWER Cellular
Questions And Complete Answers
Which is the most primitive Parazoan? - ANSWER Placozoa
Asconoid - ANSWER Simplest form of sponges, with canals leading directly from the
outside to the interior (Sac)
Syconoid + Leuconoid - ANSWER Sponge body plans with more layers
Porocytes - ANSWER (Outer) Tubular cells that allow water to flow from the outside of
the sponge to its central cavity
Myocytes - ANSWER (Outer) muscle cells
Spicules - ANSWER (Middle) small, spike shaped particles of calcium carbonate or
silicon dioxide that make up the skeleton of some sponges
Spongin - ANSWER (Middle) Flexible protein material that make up the skeleton of some
sponges.
Amoebocytes - ANSWER Cells that create other cell types
Collencytes - ANSWER Used for structural support, neuron-like
Choanocytes - ANSWER Collar cells that line the body cavity and have flagella that
circulate water in sponges (similar morphology to choanoflagelletic protists)
Class Calcarea - ANSWER calcium carbonate spicules
Class Hexactinellida - ANSWER glass sponges
Class Demospongiae - ANSWER Most sponges today are in this class
Most diverse class
Class Sclerospongiae - ANSWER coralline sponges
Metagenesis (cnidaria) - ANSWER Alternation of generations-like process between
polyp and medusa
Cnidae - ANSWER Capsule-like organelles that are contained in cnidocytes.
Nematocysts - ANSWER Cnidae type:
stinging cells
Spirocysts - ANSWER Cnidae type:
, Used for adherence
Only in Anthozoans
Ptychocysts - ANSWER Cnidae type:
Substrate used to construct tube for burrowing sea anemones.
"Nerve Net" - ANSWER Of cnidarians, a mesh of interacting neurons with no central
control organ
Class Hydrozoa - ANSWER Polyp stage dominant
Polymorphism
What type of mesoglea exists in Class Hydrozoa? - ANSWER Acellular
Where are the Cnidae located in Class Hydrozoa? - ANSWER Epidermis
Polymorphism - ANSWER The coexistence of two or more distinct forms in the same
population.
Gastrozooid - ANSWER feeding polyp
Gonozooid (Gonangium) - ANSWER reproductive polyp
Dactylzooid - ANSWER Contain nematocysts
Skeletozooid - ANSWER Produce chitinous structure
Hydra - ANSWER No metagenesis because of freshwater habitat
Obelia medusa - ANSWER Hydra-Like
Physalia - ANSWER Portuguese man-of-war
"a floating, polymorphic colony"
Class Scyphozoa - ANSWER medusa stage dominant
"Scyphomedusae" large
What type of mesoglea exists in Class Scyphozoa? - ANSWER Cellular
