Quiz on keystone Species

Quiz on keystone species 1. What is a significant consequence of removing a keystone species from an ecosystem? A. Stability in the entire ecosystem due to other species compensating B. A decrease in biodiversity due to disrupted trophic interactions C. A temporary fluctuation in species abundance without long-term effects D. An increase in the population of all species in the ecosystem Answer: A decrease in biodiversity due to disrupted trophic interactions (B) The removal of a keystone species often leads to decreased biodiversity due to disrupted interactions within trophic levels. 2. Why is it important to study keystone species for ecosystem conservation? A. They exclusively control the population of all other species B. They provide a clear measure of ecosystem health C. They are always the largest species in an ecosystem D. Their preservation can help maintain overall ecosystem integrity Answer: Their preservation can help maintain overall ecosystem integrity (D) Understanding keystone species is vital for conservation, as their preservation can help maintain the integrity of entire ecosystems. 3. What challenge arises when defining a species as a keystone species? 2 A. Measuring the impact of species is straightforward and quick B. Keystone species are easily identifiable in all ecosystems C. There is a lack of uniform criteria for assessing importance D. All species are equally important in their ecosystems Answer: There is a lack of uniform criteria for assessing importance (C) One of the major challenges in classifying a keystone species is the absence of standardized measures of 'importance' . 4. In what way can studying keystone species contribute to predictive modeling? A. It helps in forecasting ecosystem responses to changes and disturbances B. It provides insights into species' evolution over time C. It allows for the prediction of population sizes of all species D. It simplifies the complexities of ecosystem interactions Answer: It helps in forecasting ecosystem responses to changes and disturbances (A) Recognizing the roles of keystone species aids in predictive modeling of how ecosystems may respond to various changes. 5. What indirect effect may result from the removal of a keystone species? A. Immediate stability in prey populations B. Increased competition among other predator species C. Reduction of habitat variety across the ecosystem 3 D. Expansion of the keystone's habitat range Answer: Reduction of habitat variety across the ecosystem (C) The removal of a keystone species can lead to reduced habitat variety as entire ecosystems may be affected by the removal. 6. What defines a keystone species in an ecosystem? A. Species whose loss leads to significant changes in ecosystem structure. B. Species that are only found in tropical regions. C. Species that are the most abundant in their environment. D. Species that primarily interact with only one other species. Answer: Species whose loss leads to significant changes in ecosystem structure. (A) Keystone species have a disproportionately large impact on ecosystem structure and function. 7. How do sea otters function as a keystone species? A. They solely feed on fish in their habitat. B. They are primary producers in the ocean ecosystem. C. They prevent overgrazing of kelp forests by controlling sea urchin populations. D. They provide shelter for sea urchins. Answer: They prevent overgrazing of kelp forests by controlling sea urchin populations. (C) Sea otters maintain kelp forests by preying on sea urchins, which can otherwise destroy these habitats. 4 8. What is a potential consequence of removing a keystone species from an ecosystem? A. Stabilization of species populations. B. Simplification of food web interactions. C. Increased genetic diversity among species. D. Improved habitat quality for all species. Answer: Simplification of food web interactions. (B) Removal of a keystone species can lead to altered community structures and reduced complexity in food webs. 9. Which characteristic is NOT typically associated with keystone species? A. A role in multiple trophic levels. B. High interaction with other species. C. Dependency on seasonal environmental changes. D. Low abundance relative to their impact. Answer: Dependency on seasonal environmental changes. (C) Keystone species are defined by their significant influence on ecosystems, not their dependency on environmental changes. 10. In what way do beavers serve as a keystone species? A. They create habitats through dam construction that affects water ecosystems. B. They keep herbivore populations in check. C. They control shoreline erosion through vegetation. 5 D. They primarily feed on fish. Answer: They create habitats through dam construction that affects water ecosystems. (A) Beavers alter river ecosystems by building dams that provide habitat for many aquatic species. 11. What role do grizzly bears play in their ecosystems as keystone species? A. They help with nutrient cycling and seed dispersal in forests. B. They exclusively inhabit mountainous regions. C. They primarily consume fruits and nuts without contributing to nutrient cycling. D. They compete with top predators for food. Answer: They help with nutrient cycling and seed dispersal in forests. (A) Grizzly bears are essential for nutrient cycling and seed dispersal, which supports forest ecosystems. 12. Which species is considered a significant top predator in coastal ecosystems? A. Grizzly bears B. Sea stars C. Sea otters D. Wolves Answer: Sea stars (B) Sea stars play a critical role as top predators in intertidal and coastal ocean 6 ecosystems. 13. What may happen to biodiversity if a keystone species is removed from an ecosystem? A. Biodiversity is likely to remain stable. B. Species will adapt without ecological disruptions. C. Biodiversity will increase due to less competition. D. Biodiversity may decline significantly. Answer: Biodiversity may decline significantly. (D) The absence of a keystone species often leads to a loss of biodiversity as the ecological balance is disrupted.