The product of fertilization is called which of the following?

• A. Zygote
• B. Gamete
• C. Embryo
• D. Blastocyst

Answer: (A)

When a sperm and an egg unite, the immediate product is a zygote. This single cell is diploid, carrying genetic material from both parents, and it marks the start of a new organism. A gamete is simply a sperm or an egg before they fuse, not the result of fertilization. After fertilization, the zygote begins rapidly dividing (cleavage) to form a multicellular embryo, and later stages like a blastocyst occur as development continues. So the product of fertilization is the zygote.