Taxa are groups used in classification and can occur at different levels. For example, dogs are mammals, and mammals are animals: these groups do not all represent the same level. This helps you interpret references to organisms belonging to the same taxon in classification systems.
Which five plant groups are studied in this chapter, and how does it treat cyanobacteria despite their common name?
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The chapter studies algae, bryophytes, pteridophytes, gymnosperms and angiosperms. Cyanobacteria, despite the common name blue-green algae, are excluded from algae in the classification used here.
How do artificial and natural classification systems differ in the characters they use? Why can a few superficial characters be misleading?
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Artificial systems use a small selection of superficial characters and may separate closely related species. Vegetative characters can be affected by the environment. Natural systems consider affinities using both external and internal evidence, including anatomy, embryology, ultrastructure and phytochemistry.
What is the basis of phylogenetic classification, and what does it assume about organisms grouped in the same taxon?
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It is based on evolutionary relationships and assumes common ancestry among organisms grouped in the same taxon.
Distinguish numerical taxonomy, cytotaxonomy and chemotaxonomy by the evidence each uses.
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Numerical taxonomy assigns codes to observable characters and processes them, giving each character equal importance in the method described here. Cytotaxonomy uses chromosome information such as number, structure and behaviour. Chemotaxonomy uses chemical constituents.