The motherboard has a huge connector that connects to a board with either one CPU socket or a board with two sockets. And the single socket board has 4 DIMM slots while the dual socket board has 8 slots, so take that into consideration as well.
So, the answer is no, a Pro originally configured with one CPU only handles one CPU. On top of that, the CPU is a 3500 series. It only has 1 QPI path. The processors that come with the dual are 5500 series.