The Nucleus is in both plant and animal cells. The Nucleus is not always at the middle of the cell but is rarely at the edge of the cell because it’s a dangerous place for the nucleus to be since the nucleus is very important to a cell. The function of the Nucleus is to guide the cell on what to do using chromosomes – making it the control center of the cell. If a eukaryotic cell didn’t have a nucleus it wouldn’t be able to produce protein without genetic material so that would make that cell useless. A fun fact for the nucleus is that there is a part of the cell in the middle of the nucleus called the nucleolus which produces ribosomes that are transported to the rough endoplasmic reticulum.