The answer that goes in the blank is Division.
Answer:
Arthropods have a tough, non-living outer shell called exoskeleton, which protect their soft bodies while echinoderms have living endoskeletons, which develops within the deeper skin or body tissues and act as their protective covering.Explanation:
Answer:
Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body.
Explanation: