Comparison at a cell level shows common components necessary for life. Animal cells have plasma membranes, a nucleus, mitochrondrian and ribosome (Freeman, et al. 2014). In addition to these cell structures, plant cells have walls made of cellulose that provide for structure and function that animals do not have (Education.com, 2012).
Organism growth starts from a single cell, thru division developing into cell specificity. Plant growth initiates from localized centers of meristem cells at shoot and root centric locations.