Animal that has a backbone.
Animal that doesn't have a backbone.
Worm with cylindrical, segmented bodies.
Invertebrate with segmented body and jointed limbs, such as spiders and insects.
Aquatic animal that has a saclike body with stinging tentacles.
Aquatic animal, such as sea urchin or starfish, which have spiny skin.
Aquatic animal that has a soft body surrounded by a hard outer shell.
A body plan in which the organs and tissues are arranged in a circle around a central axis.
A body plan in which two halves of the body are mirror images of one another.
The early stage of an embryo that is composed of a hollow ball of cells.
A bilaterally symmetrical invertebrate whose blastophore forms into a mouth.
Opening of the blastula.
A bilaterally symmetrical invertebrate whose blastophore forms into an anus.
Specialized cells that push water through sponges and pull food from the water.
An opening in the top of the sponge through which water exits
Stinging cell that lines cnidarian tentacles.
Poison-filled structures in the tentacles of cnidarians.
The umbrella-shaped form of the cnidarian that can float freely in the water.
A cylinder-shaped cnidarian that attaches to objects on the ocean bottom and remains sedentary.
Organisms that emerge from three cell layers.
A fluid-filled cavity that forms between the tissues.
Animals that lack a coelom.
An animal that has both male and female reproductive organs.
A wall that divides the segments of a worm
The larval stage of the mollusk.
A rough, tongue-like organ in mollusks that is used for eating food.
A layer of tissue surrounding the mollusk's body that produces the shell.
A layer underneath the mantle which contains the mollusk's internal organs
The hard material on the outside of invertebrates, used for protection and support
A polysaccharide component of the arthropod exoskeleton
The process of shedding of the outer skin as the animal grows
Tube that runs through an arthropod body and enables breathing
Tube that collects wastes from the arthropod's body for removal.
The stage at which an insect transforms into its adult form
Group of crustaceans that have ten (five pairs) feet.
Specialized legs used for catching prey.
A hard protective coating on the back of an animal.
The middle part of the body in an arthropod between the head and abdomen.
Appendages used for swimming.
Arthropod that breathes air and has four pairs of legs.
Fang-like appendages near the mouth of an arachnid used to inject the prey with a paralyzing venom.
An animal that has chelicerae.
Organs in the spider that contain silk glands.
Appendages near the mouths of ticks, spiders, and other arachnids used to latch onto prey.
Any arthropod that has an elongated body composed of many segments, such as the centipede and millipede.
An internal skeleton
A structure in the echinoderm through which water enters the vascular system.
Bulb-like sacs in the echinoderm vascular system that are contracted to push the water through the canals into the foot.
A disease caused by the parasitic schistosome flatworm.
A disease caused by the parasitic roundworm Trichinella, which lives in meat.
A disease caused by microscopic parasites and transmitted through the bite of an infected Anopheles mosquito.
A disease caused by bacteria transmitted by the bite of a deer tick that causes muscle and joint aches.
Animals that are relocated from their native ecosystem to other parts of the world.
A now extinct class of arthropod.
The concentration of sense organs in the front of an animal's body.
In some invertebrates, a structure made up of nerve cells; in mammals, a group of nerve cell bodies.
Small openings through which air enters and exits the body of arthropods.