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.
The nucleus (pl. nuclei; from Latin nucleus or nuculeus, meaning kernel) is a membrane enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material (DNA), organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes.he cell nucleus contains the majority of the cell's genetic material, in the form of multiple linear DNA molecules organized into structures called chromosomes.A chromosome is an organized structure of DNA and protein that is found in cells.