What is a zygote?

A zygote is defined as a fertilized egg that results from the union of a sperm cell and an egg cell. This is the very first stage of development in sexually reproducing organisms, marking the beginning of embryogenesis. Once the sperm penetrates the egg, their genetic material combines to create a unique set of DNA, resulting in the formation of the zygote.

This stage is crucial because it represents the initial phase where the genetic information from both parents merges to form a new organism. The zygote undergoes multiple divisions and differentiation processes as it develops into a multicellular organism. Understanding the concept of a zygote is fundamental in fields such as developmental biology, reproductive medicine, and genetics, as it highlights the significance of fertilization in the life cycle of an organism.

The other choices refer to different biological concepts. A fungal infection does not relate to the fertilization process. A stage in cell division pertains to the processes of mitosis and meiosis but occurs after the formation of a zygote. Similarly, a group of cells that forms tissues refers to a later development stage beyond the zygote stage, where cells have differentiated and organized into structured forms.