Download Concept Check Questions

Concept Check Questions
Chapter 33 – Invertebrates
33.1
Sponges are sessile and have a porous body and choanocytes
1. Describe how sponges feed.
2. Explain how changes in water currents can affect sponge reproduction.
33.2
Cnidarians have radial symmetry, a gastrovascular cavity, and cnidocytes
1. Compare and contrast the polyp and medusa forms of cnidarians.
2. Describe the structure and function of the stinging cells for which cnidarians are named.
33.3
Most animals have bilateral symmetry
1. Explain how tapeworms can survive without a coelom, a mouth, a digestive system, or an
excretory system.
2. Is the presence or absence of an alimentary canal related to the size of an animal?
Support your answer with two examples.
3. Explain how, in terms of function, ectoprocts have more in common with nonbilaterian
corals than with their closer bilaterian relatives.
33.4
Molluscs have a muscular foot, a visceral mass, and a mantle
1. Explain how the modification of the molluscan foot in gastropods and cephalopods
relates to their respective lifestyles.
2. How have bivalves diverged from the basic molluscan body plan?
33.5
Annelids are segmented worms
1. Annelid anatomy can be described as “a tube within a tube.” Explain.
2. Explain how an earthworm uses its segmental muscles and coelom in movement.
33.6
Nematodes are nonsegmented pseudocoelomates covered by a tough
cuticle
1. Why would it be risky to order pork chops “rare” in a restaurant?
2. How does the nematode body plan differ from that of annelids?
33.7
Arthropods are segmented coelomates that have an exoskeleton and
jointed appendages
1. In contrast to our jaws, which more up and down, the mouthparts of arthropods move
side to side. Explain this feature of arthropods in terms of the origin of their mouthparts.
2. Would it be reasonable to call phylum Arthropoda the most successful animal phylum?
Explain your answer.
3. Describe two adaptations that enabled insects to thrive on land.
33.8
Echinoderms and chordates are deuterostomes
1. Explain how the symmetry of echinoderms and cnidarians exemplifies convergent
evolution.
2. Describe the hydraulic and muscular actions by which a sea star moves its tube feet.