On what basis, are plants and animals classified? [Pg. No. 228]

Plants and animals are classified on the basis of their similarities and differences in body structure, mode of nutrition, organisation of cells and level of complexity. Plants are commonly classified using features such as presence or absence of vascular tissues, seeds, flowers, and type of body organisation. Animals are classified using features such as body symmetry, body cavity, segmentation, presence or absence of backbone, and level of organ development. These features help in arranging organisms into systematic groups and understanding their relationships.