The Prime Meridian is 1/2 of the boundary between the eastern and western hemispheres.
The Prime Meridian is part of the boundary between the eastern and western hemispheres. The International Date Line is the rest of the boundary.
The prime meridian at longitude 0° marks the eastern boundary of the Western Hemisphere The corresponding anti-meridian at Longitude 180° marks the western boundary of the Western Hemisphere. (In practical terms you could also consider the international date line to be the boundary - just not the official boundary.)
The prime meridian divides the earth into eastern and western hemispheres, just as the equator divides it into northern and southern hemispheres. Australia is to the east of the prime meridian and is considered to be in the eastern hemisphere.
The prime meridian separates the Eastern Hemisphere from the Western Hemisphere.
The eastern hemisphere includes parts of Europe, Africa, Asia, and Australia. It is divided from the western hemisphere by the Prime Meridian.
The eastern and western hemispheres do not have a physical barrier or boundary separating them. They are demarcated based on the Prime Meridian and the International Date Line.
There are no hemispheres without an eastern or western half. Every location on Earth lies in either the eastern hemisphere (east of the Prime Meridian) or the western hemisphere (west of the Prime Meridian).
The eastern hemiphere is the half of the globe to the "right" of the Prime Meridian as far as the International Date Line. Africa, Europe, Asia, and Australia are considered to be in the eastern hemisphere, although a large region in western Africa is to the west of the meridian.
The International Date Line and the Prime Meridian both separate the eastern from the western hemisphere.
The prime meridian helps to divide the earth into the Eastern Hemisphere and the Western Hemisphere.
Half of the Prime Meridian is in the northern hemisphere, and half of it is in the southern one. Also, it is half of the boundary line between the eastern and western hemispheres, so it's in either both or neither of those.