Terms describes a muscle that is primarily responsible for causing a given action about a joint?

The  terms  include Agonist which  are  directly  involved  in  movement.
fixator   which  eliminate  unwanted  movement,  neutralizer  which  prevent  unwanted  movement,Antagonist which opposes  the  movement  of  a  joint  by  producing  torgue  and  Stabilizer  which  stabilizes  the  humeral  head  in  the  glenoid  flossa.

An autotrophic protist - they can perform photosynthesis and mainly consist of unicellular algae. they can be divided into number of systematic group according to the shape of their cell and the type of photosynthetic pigments they use.