(1) (genetics) A segment of DNA where the repressor binds to, thereby preventing the transcription of certain genes. (2) (surgery) The one performing surgical procedures. (Genetics) In the Operon Model, the operator is the gene in which a repressor binds. This results in the prevention of the RNA polymerase from binding to it, thus, preventing the expression of certain genes in the operon unit. Word origin: Latin operÄ ( rÄ« ) (to work, effect).
Newton's first law states that an object at rest will stay at rest unless acted on by an unbalanced external force.. This concept is commonly referred to as inertia and was first hypothesized by Galileo Galilei in the late 1500s.
It is thus possible for forces to act on an object, yet have the net force be zero. When evaluating the motion caused by forces acting on an object, remember to find the vector sum of those forces. Also included in Newton's First Law, though not explicitly, is the concept of inertia. Inertia is defined as the tendency of an object to remain at a constant velocity.