Here's why:
* Waterproof: The zygote is surrounded by a tough outer layer called the zona pellucida which protects it from the external environment and acts as a barrier against water.
* Reproductive cell: The zygote is formed by the fusion of a sperm cell (male gamete) and an egg cell (female gamete).
* Can grow into a new organism: The zygote undergoes a series of cell divisions and developmental processes to eventually form a complete organism.
It's important to note that the term "waterproof" is not completely accurate. While the zona pellucida provides protection, it's not entirely impermeable to water. However, it does significantly reduce the passage of water and other substances, creating a protective barrier for the developing embryo.
