1. Zygote in unicellular whereas embryo is multicellular.
2. Zygote is termed as a zygocyte in medical terms while the embryo is termed as a diploid eukaryote.
3. Zygote comes from the root Greek word ‘zygotos’ meaning yoked while embryo comes from the root Latin word ’embryum’ meaning ‘that which grows’.
4. The mitosis of the zygote results in to the formation of the embryo. So zygote is the first stage in the development of a new organism while embryo is the stage that follows next.
5. The process of zygote formation is fertilization while that of embryo is embryogenesis.