Fertilization is defined as

Fertilization is defined as

• A. The union of egg and sperm to create a new cell
• B. The division of the fertilized egg into multiple cells
• C. The implantation of the zygote into the uterus
• D. The growth of the placenta

Answer: (A)

Fertilization is the union of egg and sperm to create a new cell. This moment forms a zygote that contains a complete set of chromosomes from both parents and marks the start of development. After fertilization, the zygote begins to divide to become a multicellular embryo, then moves to the uterus to implant, and later the placenta forms to support growth. The other options describe these later stages, not fertilization itself.

Fertilization is the union of egg and sperm to create a new cell. This moment forms a zygote that contains a complete set of chromosomes from both parents and marks the start of development. After fertilization, the zygote begins to divide to become a multicellular embryo, then moves to the uterus to implant, and later the placenta forms to support growth. The other options describe these later stages, not fertilization itself.