An internal skeleton found in vertebrates and usually made of cartilage and bone.

Gives vertebrate a strong support system.

A flexible supporting tissue that makes up part or all of some animals' skeleton.

Able to maintain a constant body temperature by internal means; warm-blooded.

Not able to maintain a constant body temperature by internal means; cold-blooded.

Blood that carries an abundant amount of oxygen.

Blood that contains little oxygen.

A respiratory structure in fish and other aquatic organisms that exchange oxygen and carbon dioxide in the water.

An organ that exchanges gases between the atmosphere and the blood.

The organ that produces bile; helps regulate substances in the blood, and stores vitamins and minerals.

The muscle that separates the thorax from the abdomen in mammals and humans and that aids in breathing.

The part of the nervous system consisting of the brain and spinal cord.

The part of the nervous system consisting of sensory receptors, sensory organs, and the nerves that connect to the central nervous system.

A saclike portion of the digestive tract that performs mechanical and chemical digestion.

The long, tubular organ in which most of the digestion and absorption of food occurs.

The part of the digestive tract that extends from the end of the small intestine to the anus and absorbs water and minerals.

An organism that eats plants.

An organism that eats other animals.

An organism that eats both plants and animals.

An organ found in most vertebrates that filters wastes from the blood.