You may exit out of this review and return later without penalty.
Close
Sharing assignments in OpenClass
OpenClass is on a mission to improve & democratize education. Through our platform, educators can share assignments privately or with our entire community to improve accessibility of the best learning resources around the world.
Our assignments guide students through research-backed study sessions to reinforce learning. If this review is relevant to your teachings, feel free to add it to one of your classes!
Our format is simple and engaging: students are asked a retrieval question, then shown corrective feedback and a multiple-choice mastery question to assess their understanding of the material. Assignments adapt to unique student needs and continue to draw questions until a student has demonstrated mastery.
Explain the difference between species richness and species diversity in a community. Why is it important to consider both when studying an ecosystem?
Describe the concept of trophic structure in a community and explain how energy flows through different trophic levels.
How can the introduction of a new species affect the species richness and species diversity of a community?
Discuss how keystone species influence the trophic structure and species diversity of a community.
How does the concept of an ecological niche relate to species diversity within a community?
Describe the interaction between a predator and its prey. How does this relationship affect the population dynamics of both species involved?
Explain the concept of mutualism and provide an example of a mutualistic relationship in nature.
What is competition in an ecological context, and how can it affect the species involved?
Define commensalism and provide an example of a commensal relationship in nature.
Describe parasitism and explain how it differs from predation. Provide an example of a parasitic relationship.
Describe the role of a keystone species in an ecosystem and provide an example of a keystone species in a marine environment.
Explain how the removal of a keystone species can affect an ecosystem, using the example of wolves in Yellowstone National Park.
Discuss the role of the African elephant as a keystone species in savanna ecosystems.
How do starfish (Pisaster ochraceus) function as a keystone species in intertidal zones?
Explain the concept of a keystone species using the example of the jaguar in tropical rainforests.
Describe the role of a keystone species in an ecosystem and provide an example of a keystone species in a marine environment.
(Student response here)
A keystone species is one that has a disproportionately large impact on its ecosystem relative to its abundance. These species help maintain the structure and stability of the community by controlling populations of other species and fostering biodiversity. An example of a keystone species in a marine environment is the sea otter. Sea otters prey on sea urchins, which, if left unchecked, can overgraze kelp forests. By controlling sea urchin populations, sea otters help maintain the health and diversity of kelp forest ecosystems.
Which of the following best explains why sea otters are considered a keystone species in marine ecosystems?
They are the largest predators in their ecosystem.
They control sea urchin populations, which helps maintain the health and diversity of kelp forests.
They are the primary producers in their ecosystem.
They are the most abundant species in their ecosystem.
CLOSE REVIEW
Instructor solution