Answer to Question 1ANS: B
Cnidarians are carnivorous animals that have stinging cells. These are called cnidoblasts. The sea
jellies are in the medusa stage of cnidarians. Information can be found in the section Invertebrates Are
the Most Successful and Abundant Animals.
Answer to Question 2ANS: D
Ophiuroids, or brittle stars, have long, slender arms. They break off their arms when being attacked as
an evasive tactic. Information can be found in the section Advanced Invertebrates Have Complex
Bodies and Internal System
