What is each half called when the earth is divided into two equal halves?

The line that separates the northern and southern hemispheres is the

The line that separates the western and eastern hemispheres is the

Are lines of latitude parallel?

Parallel lines that measure the distance north or south of the equator are called lines of

Imaginary half-circles that measure the distance east or west of the prime meridian are called lines of

Do lines of latitude and longitude form a grid on Earth's surface?