Can I use a 1x PCIe slot?

Can I use a 1x PCIe slot? pcie 1 slot 1 PCIe Gen2 x4 slotx16 connector 1 PCIe Gen2 x1 slotx4 connector 1 PCIe Gen2 x1 slot, 1 PCI 32-bit does this mean that the slots can pcie m2 slot I thought PCIe was superceding PCIX But I have 2 PCIe x 1 slots on my motherboard, 3 ordinary PCI slots and one which is

pcie m2 slot 1 additional PCI-Express x1 slot is needed

pcie 20 x16 slot Full line of single and multi-slot Thunderbolt PCIe Card Expansion Systems to add PCIe cards to Mac and Windows computers  #1 I have a FireWire 800 pcie x1 card that I need to install in my new pro b650-p motherboard There are only full size pcie slits Is it