Which characters are taken into account in the Natural System of Classification?

Correct answer: Both external characters and internal anatomy

Correct answer: B. A natural classification system considers many features together so that the overall similarities among organisms are represented more realistically. These may include external morphology, internal anatomy, embryology, reproductive structures, and chemical or biochemical characters such as phytochemical evidence in plants. A is incorrect because using only external characters is too narrow and is characteristic of a simple artificial approach. C is incorrect because economic usefulness may help describe importance to humans but does not reveal natural relationships. D is incorrect because organisms living in the same habitat may be very different and may not share close ancestry. Natural classification is therefore broader than a single visible feature, although it is not exactly the same as a modern DNA-based phylogenetic system. Memory cue: natural classification uses a “bundle” of characters, not one convenient character.