Assertion : Movement of body parts serves to change the body posture.
Reason : Body parts move in relation to body axis.
Movement of body parts serves many purposes. Movement of limbs, appendages, head and trunk serve to change the body posture to maintain equilibrium against gravity. Limb movements also required for carrying out locomotion. Prehension of food involves movements of tongue, jaws, snout, tentacles, limbs and appendages in different animals. Movements of eyeballs and pinna of ear help to collect information from the external environment. Food and urine are propelled by the movement of digestive urinary tract respectively.