What is the specific term for the physical union of sperm and ova?

The process described as the physical union of sperm and ova is referred to as fertilization. This term specifically denotes the moment when the male gamete (sperm) penetrates and merges with the female gamete (ova), resulting in the formation of a zygote. This is a crucial step in sexual reproduction, leading to the development of a new organism.

In biological terms, fertilization initiates the process of embryonic development, which subsequently leads to the stages that follow in the life cycle of an organism. It's important to distinguish fertilization from other processes like meiosis, which is a type of cell division that produces gametes, and embryogenesis, which refers to the development of the embryo after fertilization. Although syngamy is also related to the process of gamete fusion, it is less commonly used in general contexts compared to fertilization.