Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What is the function of lines of longitude?

1. They measure distances north and south of the equator.

2. They measure distances east and west of the prime meridian.

3. They divide the Earth into hemispheres.

4. They help define time zones across the earth.

The correct answer is: They measure distances east and west of the prime meridian.

The function of lines of longitude is indeed to measure distances east and west of the prime meridian. Lines of longitude, which run from the North Pole to the South Pole, are expressed in degrees, with the prime meridian at 0 degrees serving as the reference point. As you move to the east or west from this line, the degrees increase up to 180 degrees, marking the eastern and western hemispheres. This system is crucial for navigation and mapping, as it allows for precise location identification and helps travelers and geographers understand their position relative to the global coordinate system. While options related to distances north and south, dividing the Earth into hemispheres, and defining time zones touch on important concepts in geography, they do not accurately describe the specific role that lines of longitude play. Lines of latitude, for instance, are responsible for measuring distances north and south of the equator.