1
Which type of skeletal system of animals is formed by the pressure exerted by the aqueous contents of the coelom on surrounding organs?
  1. hydrostatic skeleton
  2. exoskeleton
  3. axial skeleton
  4. appendicular skeleton
2
The skeletal system is necessary to support the body, protect internal organs, and allow movement. Which of the following organisms must shed and then regenerate its skeletal system as it grows?
  1. earthworm
  2. lobster
  3. snake
  4. sea

29.1Types of Skeletal Systems

The three types of skeleton designs are hydrostatic skeletons, exoskeletons, and endoskeletons. A hydrostatic skeleton is formed by a fluid-filled compartment held under hydrostatic pressure; movement is created by the muscles producing pressure on the fluid. An exoskeleton is a hard external skeleton that protects the outer surface of an organism and enables movement through muscles attached on the inside. An endoskeleton is an internal skeleton

abduction
when a bone moves away from the midline of the body
acetylcholinesterase
(AChE) enzyme that breaks down ACh into acetyl and choline
actin
globular contractile protein that interacts with myosin for muscle contraction
adduction
movement of the limbs inward after abduction
amphiarthrosis
joint that allows slight movement; includes syndesmoses and symphyses
angular movement
produced when the angle between the bones of a joint changes
appendicular skeleton
composed of the bones of the upper