Milkweed and Monarchs This edited excerpt is from an article by Acadia National Park of the National Park Service. Milkweed is the common name for many plants in the genus Asclepias. It is an herbaceous perennial, recognizable by its broad opposite leaves, colorful flower clusters, or seed pods filled with silk that carries its wind-dispersed seeds. Monarch butterflies only lay eggs on milkweed and monarch caterpillars only feed exclusively on milkweed leaves making the milkweed the only host plant for this butterfly species. There is a symbiotic relationship between the monarchs and the milkweed. The butterflies benefit by eating the nectar from the flowers and the milkweed benefits by getting help with pollination. There is also a very specialized relationship between the monarch caterpillars and the milkweed. There is a milky latex produced by the plant, which contains compounds called cardiac glycosides that are poisonous to most other animals. The monarch butterfly has developed resistance to this toxin, giving caterpillars a strong chemical defense against predators. In response, milkweed is trending toward faster regrowth following monarch caterpillar activity rather than increased toxicity. This is an example of coevolution, the process of living things influencing one another over thousands or millions of years." Image: A monarch butterfly on common milkweed by Yehyun Kim, Friends of Acadia. Question 1 5. What argument can be made, which could be supported by the evidence collected in the graph below, between the changes to the biological components (i.e. habitat, food source, egg laying location) of an ecosystem and the population of the Monarch butterfly? (1 point) Responses If the monarch population begins to recover and increase then the milkweed population will eventually go extinct. If the monarch population begins to recover and increase then the milkweed population will eventually go extinct. If the milkweed population begins to recover and increase then the monarch population will also begin to recover and increase. If the milkweed population begins to recover and increase then the monarch population will also begin to recover and increase. If the milkweed population continues to decrease then the monarch population will begin to recover and increase. If the milkweed population continues to decrease then the monarch population will begin to recover and increase. The milkweed population has no affect on the monarch population. The milkweed population has no affect on the monarch population. Question 2 6. Use the choices from the drop down menus to fill in each blank.(4 points) There is a symbiotic relationship between the monarch butterfly and the milkweed plant. Because the butterfly and the milkweed it is a relationship. There are no plant substitutes for where monarch butterflies can lay their eggs so there is a population dynamic connection between the butterfly and the milkweed plant as well. If the milkweed plants were to go extinct, then the monarch butterfly popuation would eventually because the butterfly would have nowhere to lay its eggs. Skip to navigation

Answer 1

There is a symbiotic relationship between the monarch butterfly and the milkweed plant. Because the butterfly and the milkweed coevolved, it is a coevolutionary relationship. There are no plant substitutes for where monarch butterflies can lay their eggs, so there is a population dynamic connection between the butterfly and the milkweed plant as well. If the milkweed plants were to go extinct, then the monarch butterfly population would eventually decline because the butterfly would have nowhere to lay its eggs.