The muscle that serves as the prime mover during a movement is called the

Agonist

Explanation:

The muscle that serves as a prime mover during a movement is called "agonist". Agonist refer to the leader muscles that contract and cause the movement.  

For example, the deltoid muscle is the prime mover or agonist. Contraction of deltoid muscle causes abduction of the arm. An agonist for one type of movement may serve as antagonist or fixator for some other movement.

rocks and weathering-matching

one characteristic that is shared by all is a soft body. many

of these invertebrate animals also have an outer shell to protect their

body. oysters, clams, snails, and mussels are all mollusks. so are octopuses, squids, and slugs. mollusks live on land and in freshwater.