The rivet model of community structure suggests that a) damaged communities can be repaired if species are added. b) communities are tightly integrated units that may be seriously affected by changes in the abundance of only one species. c) most communities are robust in the face of disturbance. d) top-down regulation of communities is most important. e) if one species disappears, another will probably take its place.

What is the difference between the conducting zone and the respiratory zone of the respiratory system? the conducting zone is a series of cavities and tubes that move air to the respiratory zone where gases exchange with the bloodstream. the conducting zone exchanges gases between the lungs and the alveoli and the respiratory zone is a series of cavities and tubes that move air to the conducting zone. the conducting zone moves oxygen into the cells and the respiratory zone takes carbon dioxide away from the cells. the conducting zone moves oxygen into the bloodstream and the respiratory zone takes carbon dioxide away from the bloodstream.

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels

What are characteristics of minerals? select 3 choices