Â­Mesoamericans began writing during the mid-Pre-classic period. The Mayans were the first to keep any sort of historical record, and the beginnings of the calendar were born. The Mayans used stelae, or stone monuments, to carve their civil events, calendars and astronomy knowledge. They also inscribed their religious beliefs and mythology on pottery.
The nucleus is a membrane bound structure that contains the cell's hereditary information and controls the cell's growth and reproduction. It is commonly the most prominent organelle in the cell. The nucleus is surrounded by a structure called the nuclear envelope.
Plant and animal cells are different.Animal cells have 5  parts.    Nucleus  Cytoplasm  Mitochondria  Vacuoles  Cell membrane   1. Nucleus is like a person's bra â¦ in.it tells the cell how to do  it's job.   2. The cell membrane is like the skin.It lets things is and out of  the cell.   3. Vacuoles store water for the cell.they also store waste  products.   4. Cytoplasm is like water or liquid and fills the inside of the  cell.it holds the other parts of the cell in place.   5.