Some embodiments include memory cells that contain a dynamic random access memory (DRAM) element and a nonvolatile memory (NVM) element. The DRAM element contains two types of DRAM nanoparticles that differ in work function. The NVM contains two types of NVM nanoparticles that differ in trapping depth. The NVM nanoparticles may be in vertically displaced charge-trapping planes. The memory cell contains a tunnel dielectric, and one of the charge-trapping planes of the NVM may be further from the tunnel dielectric than the other. The NVM charge-trapping plane that is further from the tunnel dielectric may contain larger NVM nanoparticles than the other NVM charge-trapping plane. The DRAM element may contain a single charge-trapping plane that has both types of DRAM nanoparticles therein. The memory cells may be incorporated into electronic systems.