The symbols +, −, and 0 are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, − denotes a negative interaction, and 0 denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned.
- What does the graph in the accompanying figure tell you about the definition of a keystone species?
A) A keystone species has little interaction with other species in an environment.
B) Removing a keystone species from the community drastically reduces diversity.
C) Adding a keystone species to the community will make it more diverse.
D) Removing a keystone species from the community will eventually allow for the invasion of a new species.

Question

The symbols +, −, and 0 are to be used to show the results of interactions between individuals and groups of individuals in the examples that follow. The symbol + denotes a positive interaction, − denotes a negative interaction, and 0 denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned.
- What does the graph in the accompanying figure tell you about the definition of a keystone species?
A) A keystone species has little interaction with other species in an environment. 
B) Removing a keystone species from the community drastically reduces diversity. 
C) Adding a keystone species to the community will make it more diverse. 
D) Removing a keystone species from the community will eventually allow for the invasion of a new species.

Quizplus · Accepted Answer

The graph shows that removing the keystone species (sea star) drastically reduces the diversity of the community, indicating that the keystone species plays a crucial role in maintaining species diversity. This supports the definition of a keystone species as a species that has a disproportionately large effect on the community relative to its abundance or biomass. Therefore, option B, "Removing a keystone species from the community drastically reduces diversity," is the best choice.

The Symbols +, −, and 0 Are to Be Used