How many constellations in the Earth?
There are no constellations in the Earth. They are in space. There are 88 official constellations.
Why do the planets appear to move through the constellations instead of with the constellations as Earth rotates?
(circumpolar - our view of the constellation on Earth) Constellations are circumpolar because they are only how we view them on Earth. The constellations would be different on another planet or at another viewing point. They are circumpolar since they are at different distances in relation to each other and to the Earth.