Final answer:
The result of the union of sex cells (sperm and egg) is the formation of a zygote.
Step-by-step explanation:
The result of the union of sex cells (sperm and egg) is the formation of a zygote. When a sperm penetrates the egg, it triggers the egg to complete meiosis. The resulting cell, called a zygote, contains all the chromosomes needed for a new human organism. Half the chromosomes come from the egg and half from the sperm.