Here's the breakdown:
* Zygote: This is the first cell of a new organism, formed by the fusion of a sperm and egg.
* Morula: This is a solid ball of cells formed by multiple cell divisions of the zygote. It occurs after the zygote undergoes a series of mitotic divisions.
Think of it like this:
* Zygote: The seed of a plant
* Morula: The seed starting to sprout and form a ball of cells
So, while they are both related to early embryonic development, they are distinct stages.