ASIM'S WEBWORLD View: Main School Main AP Biology Chapter Guides RELATED LINKS Chapter Outline		AP BIOLOGY: Chapter Twenty-Five Review Answers 1. Coevolution is long-term mutual evolutionary adjustment in the characteristics of organisms with relation to one another. Examples include the following: fruit provides food for animals which then increase seed dispersal of the plants; pollen or nectar provides animal food and causes flower pollination. 2. Defense structures include thorns, spines, prickles, sticky plant hairs, and high levels of silica. Nutritionally, if a plant lacks several of the 12 essential amino acids, it is less likely to be useful food. 3. Primary chemical compounds are regularly formed as components of various metabolic pathways; secondary compounds are chemicals not involved in metabolic pathways. Overgrazing is prevented by these secondary compounds because they may be unpalatable or toxic to metabolic processes or development. 4. These organisms evolved mechanisms over time that allowed them to break down the irritating compounds. By feeding on plants few to no other organisms eat, they are reducing outside competition on their food source. 5. Cryptic coloration provides camouflage, hiding the animal from predators. Aposematic coloration is highly visible and indicates the presence of some defensive mechanism. An animal that stores a plant's secondary chemicals will generally be poisonous and brightly colored, whereas an animal that degrades the compounds generally will not be poisonous and may be camouflaged. 6. Batesian mimicry describes the situation when an unprotected species evolves to resemble a chemically protected species. The purpose for the possessor is that it will not be preyed upon by those predators familiar with the model. 7. There must be a much smaller number of mimics than aposematics. If there are the same number of or more mimics, the predators will have a good chance of getting an unprotected individual rather than a protected individual and will not learn avoidance of the model. 8. The adult viceroy butterfly exhibits Batesian mimicry; the larval monarch butterfly exhibits aposematic coloration; and the larval viceroy butterfly exhibits cryptic coloration. 9. In Mullerian mimicry, several unrelated but usually dangerous or unpalatable organisms come to resemble each other, such as wasps and other stinging wasplike insects, gaining "safety in numbers" when the intelligent predators avoid them all as a group. These groups of organisms are typically equipped with bright warning colors, such as red or yellow. 10. Symbiotic relationships involve two or more kinds of organisms living together in a more or less permanent situation. The classes of symbiosis are (1) commensalism, in which one organism benefits while the other neither benefits nor is harmed; (2) mutualism, in which both organisms benefit; and (3) parasitism, in which one organism benefits while the other is harmed. 11. Ants on the acacia tree-mutualism; dodder and host plant-parasitism; sea anemones and anemone fish-commensalism; ants and aphids-mutualism; lice and birds-parasitism; lichens-mutualism; legume root nodules-mutualism; and fleas and humans-parasitism.