Question

1. a gradual process of change and replacement of the types of species in a community. primary succession a tertiary cycle ecological succession pioneer species 8. which of the following is part of the nitrogen cycle? conversion of atmospheric nitrogen into usable organic a compounds by bacteria nitrogen fixation all answers are correct. conversion of nitrogen from decaying organisms into ammonia 9. the type of organisms that convert the nitrogen in the atmosphere into chemical compounds that other organisms can use are. 10. nitrogen is needed by organisms to make.

Explanation:

• Question 7: Ecological succession is the gradual process of change and replacement of species in a community. Primary succession is a type of ecological succession. Tertiary cycle is not a standard ecological term. Pioneer species are the first species to colonize an area during succession.
• Question 8: Nitrogen fixation (by bacteria converting atmospheric nitrogen into usable organic compounds) and conversion of nitrogen from decaying organisms into ammonia are both part of the nitrogen cycle. So all answers (A, B, D) being correct (option C) is valid.
• Question 9: Bacteria (specifically nitrogen - fixing bacteria) convert atmospheric nitrogen into chemical compounds that other organisms can use.
• Question 10: Nitrogen is needed by organisms to make proteins (and nucleic acids like DNA and RNA).

Answer:

1. C. ecological succession
2. C. All answers are correct.
3. Bacteria (nitrogen - fixing bacteria)
4. Proteins (and nucleic acids)