Ok, you got one PCI-E x16 slot for GPU on your MB, so technically any PCI-E GPU would fit-in there, it could be PCI-E x16 2.0/3.0. doesn't matter.
SO it means that i can insert any graphic card irrespective of 2.0 or 3.0 ? Right ?
But I would like to suggest you, don't go for any expensive GPU or in other words high performance GPU's, cause your CPU could bottleneck the GPU, and there is another thing, that is your system memory (RAM), which you couldn't stress more than 4GB. Modern day games will require you to have min, 8GB of RAM for smooth operation.
My motherboard ram is maximum 2 gb ddr2 capacity and i have 2 gb installed so i cannot have any more modification in my ram section.
Now comes the question of PSU/SMPS ! What do you have ? Is it a branded one or a local one ? If its a local one than you have to buy a decent brand PSU, else you wont be able to power your GPU. I know there are some GPU's which don't require much power, but still they require some to operate, which a local PSU cant generate.
My PSU is 450W local power supply .
Then comes the question, do you have a big enough cabinet to put-on the GPU ? are there enough ventilation to keep the GPU cool ?
My Cabinet is big enough to house a graphic card. If not i can break some part of the cabinet so as to store it.
For ventilation, i can add another fan in the cabinet.
Now, if you are still desperate enough to play games then go for GTX 750ti or GTX 950, but again I would suggest you not to spend more money on your current system, it could be fatal. Hope I made myself clear. Thanks.