4. nitrogen gas is more abundant in our atmosphere than
oxyganl however, nitrogen needs to be converted into
different forms to be used by many organlams. bacteria ara
highly involved in thisl describe the role of (a) bacteris
fixing nitrogen as they liva symblotically with some plant
species, (b) nitrifying bacteria, and (c) denitrifying bacteria
in the nitrogen cycle."

Which of the following is true about the introduction of a non-native species to an environment? (a) they usually adapt quickly so they can have a positive affect on the environment. (b) they can disrupt the environment and cause much damage and devastation to native species. (c) they usually become predators in a food chain and to keep prey populations under control. (d) because the native species are better-adapted to the environment, the non-native species always end up dying out.