11. Which of the following is a characteristic of cnidarians?
a) They have a hard exoskeleton
b) They have a segmented body
c) They have stinging cells
d) They have jointed appendages
Answer: c) They have stinging cells
12. What is the body plan of a sponge?
a) Radial symmetry
b) Bilateral symmetry
c) Asymmetrical
d) Spherical
Answer: c) Asymmetrical
13. Which of the following is a characteristic of arachnids?
a) They have jointed appendages
b) They have three pairs of legs
c) They have a soft body
d) They respire through gills
Answer: a) They have jointed appendages
14. How many legs do insects typically have?
a) 4
b) 6
c) 8
d) 10
Answer: b) 6
15. Which of the following is a phylum of marine invertebrates?
a) Chordata
b) Nematoda
c) Cnidaria
d) Mollusca
Answer: c) Cnidaria
