How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

The criteria (norms) for deciding divisions in plants are different from the criteria for deciding the sub- groups among animals because the basic designs of their body is different. This is mainly due to the fact that plants are autotrophic and often remain fixed to substratum, while animals are heterotrophic and they can move. Thus, the body design of the two groups is based on the need to make their own food in case of plants and to acquire it from external source in case of animals. The other characteristics such as Presence or absence of skeleton, etc., are used to make subgroups among animals.