Chinmoy Debnath :
PCIe x16 Slots- Generation 3.0/ 2.0, 1
what does it means PCIe x16 slot running at 3.0 or 2.0 bcz my GPU supports 3.0
PCi-E 3.0 slot backward is compatible with 2.0 and 1.1/1.0 VGAs also.
On topic : if you don't have the desire to OC and only need to run your CPU at stock clock then the cheapest B75 motherboard that is NOT from Asrock or Asus should do the job well. But since you've taken the 3570k, which means you want to OC your CPU, get at least a Z75 motherboard or, if you can't find any Z75 motherboard there, a Z77 motherboard with heatsink around CPU area.