Rocker arms, in conjunction with the camshafts, do so. The camshaft has an egg pattern on it, and this pushes the rocker arms up and down. The rocker arms are connected to the valves, and this puts the fuel/air mixture into the engine, then takes it out again
Hinge ligaments
muscles :)
the umbo
It controls opening and closing of stomata .
The opening, the body fo the interview and the closing
push rods connected to the camshaft
the adavctor muscle
guard cells
The opposite of opening would be closing or shutting.
by opening their mouths then closing it then opening it again, then closing it:-)
opening is 1500 n closing is 4889
governor senses the speed of spindle of engine and controls the mechanism of opening and closing of throttle valve