pci express
In most languages with a null reference, it is simply a memory address to a zero-length memory block. So the only memory it would occupy in these cases would be enough for a memory pointer: usually around 4 bytes.
Germans
It is usually called just a Video Game Designer. Or it would fall under the category of Video game art development.
The opposite of occupy (move in) is "vacate" (leave). The opposite of occupy (take over) would be to surrender or yield. The opposite of occupy (one's attention) could be to divert.
Autotroph
There would literally be no air as there would be no space for it to occupy. If you compress air sufficiently it will liquify, but stilll occupy a discrete volumes.
Primary producer
18 cm^3
.012 grams
Primary producer
That the Germans would completely occupy it
If 2 mouse species tried to occupy the same niche they would fight. The mice fight to right to occupy the niche. The winner of the fight gets the niche.