Invertebrate Groups
These are the simplest invertebrates.
What are sponges?
When both sides of an animal’s body mirror each other.
What is bilateral symmetry?
Animals with jointed limbs and an exoskeleton belong to this phylum.
What are arthropods?
This system helps echinoderms move and capture food.
What is the water vascular system?
Where most animals digest food.
What is the gut?
This phylum includes gastropods, bivalves, and cephalopods.
What are mollusks?
A hard outer covering that protects many arthropods.
What is an exoskeleton?
Arthropods with two pairs of antennae and gills.
What are crustaceans?
Animals like sea stars belong to this phylum.
What are echinoderms?
Animals that go through egg → larva → pupa → adult undergo this.
What is complete metamorphosis?
Jellyfish and sea anemones belong to this group.
What are cnidarians?
The soft body covering in mollusks that can form a shell.
What is the mantle?
Arthropods with one pair of antennae and compound eyes.
What are insects?
Echinoderms move using these structures.
What are tube feet?
This type of behavior is instinctive and not learned.
What is innate behavior?
Earthworms belong to this phylum.
What are annelid worms?
The circulatory system that pumps blood into sinuses instead of vessels.
What is an open circulatory system?
Arthropods with no antennae and chelicerae like spiders.
What are arachnids?
Adult echinoderms usually have this type of symmetry.
What is radial symmetry?
Tapeworms are an example of this type of organism.
What is a parasite?
Planarians and flukes are examples of these worms.
What are flatworms?
The internal skeleton found in animals like sea urchins.
What is an endoskeleton?
Wormlike arthropods with many legs.
What are centipedes?
Adult echinoderms usually have this type of symmetry.
What is a sea star, brittle star, sea cucumber, sea urchin, or sand dollar?
Arthropods get oxygen to tissues through this process.