Scientists had long wondered what biological processes allow atmospheric nitrogen to be converted into a form usable by plants and other organisms. Nitrogen is an essential element found in DNA and RNA. In the late 1880's, scientists discovered that some bacteria are capable of carrying out the process. They named the process nitrogen fixation. During nitrogen fixation, bacteria produce other nitrogen-containing compounds that can be used by plants. The nitrogen can then be passed on from plants to other organisms in the food chain. The process of nitrogen fixation is now well understood and has become the basis for agricultural practices such as crop rotation.
Based on the given information, which of these is true?
A.
Bacteria will eventually turn all atmospheric nitrogen into ammonia and damage ecosystems.
B.
Bacteria are beneficial to plants, but they cause harm and disease to animals.
C.
Bacteria increase the number of plants and decrease the number of animals in an ecosystem.
D.
Bacteria help maintain the health of an ecosystem by providing nutrients.