Final answer:
The statement that a high development of agonist-antagonist function is essential for a well-aligned and balanced body is TRUE. Synergists help agonists, whereas antagonists provide resistance to the agonists' movement. Moreover, normal reaction does not oppose gravity but acts perpendicular to the surface as a reaction to it.
Step-by-step explanation:
A high development of the agonist-antagonist function is essential to the development of a well-aligned and balanced body: TRUE. In the context of muscle function, agonists are the muscles primarily responsible for producing a movement, while antagonists are the muscles that oppose the movement of the agonists. A well-developed relationship between these muscles ensures proper joint movement and stability, preventing injuries and promoting balance in the body. This principle underlies many essential biological activities, as described by the principle 4.A.4 Interactions and coordination between organ systems.
The muscle helping an agonist work would be a synergist because they assist with the movement, while the fixator stabilizes the muscle's origin. Antagonists, on the other hand, provide resistance and balance to the movement of agonists.
The statement about normal reaction being the force that opposes gravity is FALSE. Normal reaction, also known as the normal force, is the support force exerted upon an object that is in contact with another stable object. It acts perpendicular to the surface of contact and is a reaction to the force of gravity, not in the direction of it.