Chapter 31 Flashcards
Animals that have no particular symmetry exhibit
asymmetry
Which type of animal symmetry produces mirror images of each other no matter how the animal is sliced longitudinally?
radial symmetry
The term deuterostome refers to
the second embryonic opening becoming the mouth.
Which difference distinguishes protostomes from deuterostomes?
Their embryonic development is different.
T or F? Protostomes form a true coelom.
True
T or F? In protostomes, the first opening during embryonic development becomes the anus.
False
T or F? Protostomes will become mollusks, annelids, and arthropods
True
T or F? Protostomes are more advanced than acoelomates, but not as advanced as deuterostomes
True
T or F? Sponges have no nerve fibers.
True
T or F? Sponges have no fully developed muscle fibers.
True
T or F? Amoeboid cells capture food particles from the water.
False
T or F? Sponges may reproduce asexually by budding or by regeneration from a small piece.
True
Why are real bath sponges so soft?
The harder silica or calcium spicules are absent and the softer spongin remains.
A recent study of the marine hawksbill turtle’s stomach contents revealed that sponges constitute a major portion of their diet. Sponge beds are generally protected from predators by the sponge’s calcium and silica crystals, but these were found in quantity in the turtles’ digestive systems. These structures that protect the sponges from most predators, but not turtles, are
spicules
Which of the following organisms exhibit radial symmetry as adults?
cnidarians
T or F? In cnidaria, the adult body is bilaterally symmetrical.
False
T or F? In cnidaria, there are two tissue layers: an outer epidermis and inner gastrodermis.
True
T or F? In cnidaria, stinging cells contain a threadlike nematocyst released to capture prey.
True
T or F? In cnidaria, a jellylike mesoglea contains cells that form a nerve net throughout the body
True
The stinging cells or nematocysts are characteristic of
cnidarians
The molluscs look so different, and yet we can tell they are related because they all
have a mantle, visceral mass, and a foot.
Which of the following is NOT characteristic of earthworms?
A. segmentation
B. hermaphroditic
C. paired nephridia in each segment
D. dorsal solid nerve cord
D. dorsal solid nerve cord
Earthworms are
annelids.
Which type of organism is characterized by having jointed appendages, ability to molt, and three sets of fused segments?
arthropods
