Question

which process involves two gametes uniting to form a single cell, such as when a sperm combines with an egg to form a zygote?

Answer 1

The process you are describing is known as **fertilization**. During fertilization, two gametes (sperm from the male and egg from the female) unite to form a single new cell called a zygote. This zygote eventually undergoes cell division and develops into an embryo.