Organ Systems

Before DNA analyses were available, taxonomists looked at the various animal organ systems, especially the skeletal system, to determine relationships among animals. The list below is of several organ systems found in all animals.

• Which ones do you think make cheetahs unique among the felids?
  • Endocrine System
  • Digestive System
  • Nervous System
  • Muscular System
  • Excretory System
  • Respiratory System
  • Circulatory System
  • Immune System
  • Integumentary System
  • Reproductive System
  • Skeletal System