mountains, in deserts, are more frequent and higher than those on terras

Well, it would make sense from a geological perspective - Terras are earth-like planets containing liquid water, so rain and liquid flow would slowly erode and flatten the mountains, while Deserts have no water, therefore mountains can grow to virtually any size there.

Well, it would make sense from a geological perspective ... rain and liquid flow would slowly erode and flatten the mountains, while Deserts have no water .... .

But also, water allows plate tectonics, as we see Venus and Mars have little to no liquid water and so no plate tectonics.

Unless there's been a major paradigm shift in the geology field that I haven't heard about, water has nothing to do with plate tectonics.

The plates in the crust make up the lithosphere, which as the name implies is a sphere of hard rock. They float on top of the asthenosphere, which is a layer made of liquid magma. In the case of continents, the rock is less dense and remains on top, but in the case of the sea floor, the rock is more dense (it's made of the same minerals, but denser because it is cooler). Thus the edges of the oceanic plates are generally either new rock being formed from magma bubbling up or old rock sinking into the mantle, slowly dragging the rest of the plate along with it.

It does require liquid, but it's subsurface magma that it requires, not water.

parameciumkid, I actually also thought that Alek's claim wasn't correct at first, but I looked it up and from what I have gathered it is actually partially correct. Oceans are required for Earth-style plate tectonics, since the oceans seem to be the cause of the lithosphere fracturing(or something to that effect).

The oceans allow for easier movement. Water has the effect of grease in an engine, where plate tectonics may work without it but it has to be specially made and would be quite rare, because water allows the plates to not grind against each other as much, causing movement to occur faster and easier.

The temperature you search for is only the planets average temperature. At a specific point in the orbit it may be higher or lower due to eccentricity and since you chose a narrow temperature range the temperature will almost always go out of bounds at some point in the orbit.

The oceans allow for easier movement. Water has the effect of grease in an engine, where plate tectonics may work without it but it has to be specially made and would be quite rare, because water allows the plates to not grind against each other as much, causing movement to occur faster and easier.

Alek, I never heard of this "feature" of the oceans. Can you cite some article or source from which you brought this information?