1) The structure of plastids, as in the number of membranes which they contain. 2) The presence of hard outer coverings and the chemical nature of any such covering. 3) The mode of nutrition (photoautotroph, chemoheterotroph. etc.). 4) The means used for reproduction (sexual, asexual, fine details of how these are achieved).
Work Step by Step
Review Concept 28.1, making a list of features for which protists differ— any four of these will correctly answer the question.