Illinois Nail Technician Practice Exam

What are the three types of skeletal systems found in animals?

1. Hydrostatic skeleton, exoskeleton, and endo skeleton

2. Hard shell, soft body, and rigid skeleton

3. Cartilage, bone, and liquid skeleton

4. External shell, internal organs, and cartilage

The correct answer is: Hydrostatic skeleton, exoskeleton, and endo skeleton

The three types of skeletal systems found in animals are accurately represented by hydrostatic skeletons, exoskeletons, and endoskeletons. A hydrostatic skeleton is made up of a fluid-filled cavity surrounded by muscle; this allows animals such as jellyfish and earthworms to maintain shape and facilitate movement. Exoskeletons, on the other hand, are hard outer structures found in arthropods like insects and crustaceans, providing both protection and support while allowing for mobility. Endoskeletons are internal frameworks, such as bones and cartilage, found in vertebrates, which support the body and protect internal organs. The other options do not accurately categorize the types of skeletal systems in animals. While hard shells, soft bodies, and rigid skeletons might describe some physical traits of specific organisms, they do not represent the broader functional categories of skeletal systems. Similarly, cartilage, bone, and liquid skeleton are components and descriptors rather than distinct types of skeletal systems. Lastly, external shell, internal organs, and cartilage mix different anatomical structures that do not correspond to a unified classification system for skeletal support.