Question: why are we made up of lots of cells and not just one cell?

Lucy Oldacre-Bartley answered on 16 Nov 2016:

Good question – mainly because we are made up of lots of different organs and tissues that have different jobs. In order to do these jobs properly the cells need different proteins and other things to help do the job right. Therefore one big cell wouldn’t really work effectively.
Also our cells are dying and being replaced all the time – this would be more difficult if we only had one. ☺️