What enables the sperm to be guided to the ovum in order for fertilization to occur?

As long as a sperm cell is alive in the fallopian tube, it's capable of fertilizing an egg. If there's no egg in the fallopian tube, there's no chance of fertilization.
The fallopian tubes are about four inches (10 centimeters) long and transport the egg from the ovary to the uterus. They also provide sperm that make it that far with nutrients and a safe environment, the same kind the egg enjoys as it passes through. Of the millions of sperm cells that initially enter the cervix, there may be anywhere from one to a couple hundred that arrive at the fallopian tube