1. The polynomial system employed a string of several names to identify single organisms. It could vary from individual to individual, and so was both a cumbersome and nonsystematic technique for identification.
2. The current hierarchical taxonomic system names are as follows: species, genus, family, order, class, phylum, and kingdom. Genus and species are either underlined or italicized, and the species name is not capitalized.
3. Prokaryotes lack membrane-bound organelles and microtubules, their DNA is not associated with proteins, their sexual recombination is different, and their cell walls contain muramic acid. Prokaryotes and eukaryotes exhibit a greater fundamental difference. Prokaryotes are contained within the kingdoms Archaebacteria and Eubacteria.
4. The Fungi, Plantae, and Animalia have evolved from Protista; most individuals in this kingdom are unicellular but there is no common characteristic-they are not plants, animals, or fungi. In terms of nutrition and locomotion, Animalia ingest food and are highly motile; Plantae manufacture food and are generally stationary; and Fungi digest food extracellularly and absorb it and are wholly nonmotile.
5. Of the eukaryotic kingdoms, the Protista are the most diverse; their common names are protozoa for the heterotrophic members and algae for the autotrophic members. Multicellular forms are exhibited by the red, brown, and green algae.
6. Mitochondria and chloroplasts are apparently of symbiotic origin, and mitochondria are possessed by nearly all eukaryotic organisms. This organelle is most closely related to nonsulfur purple bacteria. Three ancestors appear to have given rise to the other organelle because there are three distinct biochemical categories of chloroplasts.
7. Multicellular organisms possess a significant degree of coordination and integration among the individual cells of the group. Multicellularity arose many times in the evolutionary process. Its advantages are the ability to carry out activities, including self-protection, movement, and search for food and mates, with a complexity not possible by unicellular organisms.
8. Stress prompts sexual reproduction in many unicellular protists. The three major life cycles in eukaryotes are (1) zygotic meiosis, in which the zygote is the only diploid cell and, on forming it, the cell immediately undergoes meiosis; (2) gametic meiosis, in which the gametes are the only haploid cells, and two fuse and form the diploid zygote that grows to adulthood; and (3) sporic meiosis, in which there is a regular alternation of generations between a multicellular haploid phase and a multicellular diploid phase. The diploid phase produces spores that grow into a haploid phase, which then produces gametes, two of which then fuse to form the diploid zygote, the first cell of the multicellular diploid phase.
9. As many characteristics as possible are used in a phenetic analysis. Statistically-determined significant characters are given more weight or emphasis in phenetic analysis.
10. Analogous structures are structures that are similar in appearance or function, but do not share a common evolutionary descent. Homologous structures share a common evolutionary descent.
11. Features reflecting evolutionary relatedness are used in cladistics. The resulting cladogram shows the historical order in which evolutionary branches arose during the history of the group. Most present classification schemes employ both phenetic and cladistic techniques; while cladistics contributes recognition of derived characters, phenetics addresses the degree of divergence (see figure 29.10).