water is drawn in through pores into a cavity called the spongocoel, and out through opening called osculum
Body plan of a cnidarian
sac w/ central digestive compartment = gastrovascular cavity, which serves as a hydrostatic skeleton
Echinoderms have a unique..
water vascular system, a network of hydraulic canals branching into tube feet that function in locomotion, feeding, and gas exchange.
A radially symmetrical animal that has two embryonic tissue layers probably belongs to which phylum?
Which cells in a sponge are primarily responsible for trapping and removing food particles from circulating water?
What would be the most effective method of reducing the incidence of blood flukes in a human population?
Reduce the freshwater snail population
Some species of this annelid class release an anticoagulant that is of medical significance?
Infection with which parasite might cause excessive elasticity in human skeletal muscles
Which of the following are entirely, or partly, composed of calcium carbonate?
coral animals' exoskeletons
Which of the following characteristics most likely explains why insects are so successful at dispersing to distant environments?
Protostomes that have an open circulatory system and an exoskeleton of chitin are part of which phylum?
Protostomes with a unique drape of tissue that may secrete a shell are part of which phylum?