PLASMIC a.
replicating independently of the chromosome, but transferred, like the chromosome, to subsequent generations. In bacteria, plasmids often carry the genes for antibiotic resistance; they are exploited in genetic engineering as the vehicles for introduction of extraneous DNA into cells, to alter the genetic makeup of th…
POLYGON n.
A plane figure having many angles, and consequently many sides; esp., one whose perimeter consists of more than four sides; any figure having many angles. Polygon of forces (Mech.), a polygonal figure, the sides of which, taken successively, represent, in length and direction, several forces acting simultaneously upon…