What is the term for the cell resulting from the union of an ovum and a spermatozoon?

The term for the cell that results from the union of an ovum (egg) and a spermatozoon (sperm) is called a zygote. This is the first stage in the development of a new organism following fertilization. The zygote contains a complete set of genetic material, with half coming from the mother and half from the father, and it will undergo multiple rounds of division as it develops into an embryo.

In contrast, an embryo refers to the developing organism after the zygote stage, specifically during the early stages of development, but before it becomes a recognizable organism. A gamete is a reproductive cell, specifically the sperm or the ovum, that participates in fertilization but is not the product of their union. Chloroplasts, on the other hand, are organelles found in plant cells that are responsible for photosynthesis and are unrelated to the process of fertilization or the formation of new organisms.