When DNA is copied, sometimes a new, incorrect, base pairing appears within the structure of a new DNA molecule replacing original base pairs. This mistake is called a base-pair .

Question 54 options:

Deletion

Insertion

Point

Duplication

explanation:

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.