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Community Interactions: Mutualism (+/+) & Commensalism (+/0) quiz #3

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  • How does commensalism differ from mutualism?
    Commensalism is a community interaction where one organism benefits while the other is unaffected, making it a plus zero (+/0) interaction, unlike mutualism where both benefit.
  • Give an example of a mutualistic relationship described in the lesson.
    An example is the relationship between the red-billed oxpecker and the impala, where the bird eats ticks off the impala, benefiting both.
  • What is the definition of symbiosis?
    Symbiosis refers to any close and prolonged interaction between two species.
  • How is exploitation different from mutualism and commensalism?
    Exploitation is a plus minus (+/−) interaction where one organism benefits at the expense of another, unlike mutualism (+/+) and commensalism (+/0).
  • What is the effect of competition on the fitness of organisms involved?
    Competition negatively affects the fitness of all organisms involved, making it a minus minus (−/−) interaction.
  • How does commensalism often benefit the benefiting organism?
    The benefiting organism in commensalism may use the other for shelter, food, transportation, or habitat.
  • Can mutualistic relationships be non-obligate? Explain.
    Yes, mutualistic relationships can be non-obligate, meaning the organisms benefit from each other but do not depend on the relationship for survival.
  • What is a plus zero interaction in ecological terms?
    A plus zero interaction is one in which one organism benefits and the other is unaffected, as seen in commensalism.
  • What is the main difference between parasitism and mutualism?
    In parasitism, one organism benefits while the other is harmed (+/−), whereas in mutualism, both benefit (+/+).
  • How does the impala benefit from its relationship with the red-billed oxpecker?
    The impala benefits by having parasites (ticks) removed from its fur.
  • Can commensalism involve transportation? Give an example.
    Yes, commensalism can involve transportation, such as when one organism uses another for movement without affecting it.
  • Why is parasitism considered a form of exploitation?
    Parasitism is considered exploitation because the parasite benefits at the expense of the host, which is harmed.
  • How does character displacement relate to competition?
    Character displacement occurs when species evolve differences to minimize competition for resources.
  • What is the fitness effect of commensalism on the unaffected organism?
    The fitness of the unaffected organism in commensalism remains unchanged.
  • How are mutualism and commensalism different from competition?
    Mutualism and commensalism involve at least one organism benefiting, while competition harms all involved.
  • What are two types of symbiotic relationships found in plant roots, and how do they differ in terms of benefits to the organisms involved?
    Two types of symbiotic relationships in plant roots are mutualism and commensalism. In mutualism, both organisms benefit from the interaction (plus-plus), while in commensalism, one organism benefits and the other is unaffected (plus-zero). Both are forms of symbiosis, which refers to close and prolonged interactions between species.