1. Which organisms are capable of converting gaseous nitrogen in the air into a form that other living organisms can use?
A. nitrogen-fixing bacteria
B. denitrifying bacteria
C. decomposers
D. producers
2. Which step in the nitrogen cycle is accelerated at the beginning of the eutrophication process?
A, denitrification
B. nitrogen fixation
C. producer uptake of nitrogen
D. consumer decomposition
3. Which of the following is carried out by denitrifying bacteria?
A. break down large, nitrogen-rich molecules to simple molecules
B. build large, nitrogen-rich molecules from simple molecules
C. convert biologically useful nitrogen to gaseous nitrogen
D. convert gaseous nitrogen to biologically useful nitrogen
4. Which type of organism moves nitrogen from cells of producers back to the soil?
A. decomposers
B. consumers
C. nitrogen-fixing bacteria
D. denitrifying bacteria
5. What would be the consequence of an ecosystem that had no nitrogen-fixing bacteria?
A. Nitrogen from decomposing animals would never be returned to the soil.
B. Decomposers would not be able to break down the nitrogen present in plants they feed on.
C. Plants would have to rely on biologically available nitrogen present in the soil.
D. Consumers would not survive since they would have no way to obtain the nitrogen they need.
My anwers so far:
1.A
2.C
3.D or C
4.A
5.C
1. How to get the answer: To answer this question, you need knowledge about the nitrogen cycle and the role of different organisms in it. Nitrogen-fixing bacteria are known to convert gaseous nitrogen in the air into a form that other organisms can use, so the correct answer is A.
2. How to get the answer: The question asks about which step in the nitrogen cycle is accelerated at the beginning of eutrophication. To answer this, you need to know about the nitrogen cycle and how eutrophication affects it. In eutrophication, excessive nutrients, including nitrogen, enter a body of water, causing an increase in algal growth. This increase in algal growth is primarily due to increased nitrogen availability, which is facilitated by an acceleration of producer uptake of nitrogen. Therefore, the correct answer is C.
3. How to get the answer: This question is asking about the specific role of denitrifying bacteria. To answer this, you need to know about the nitrogen cycle and the role of denitrifying bacteria in it. Denitrifying bacteria convert biologically useful nitrogen into gaseous nitrogen, so the correct answer is C.
4. How to get the answer: This question asks about the type of organism that moves nitrogen from cells of producers back to the soil. To answer this, you need to understand the nitrogen cycle and the role of different organisms in it. Decomposers are the organisms responsible for breaking down the organic matter and returning nitrogen to the soil. Hence, the correct answer is A.
5. How to get the answer: This question is asking about the consequence of an ecosystem without nitrogen-fixing bacteria. To answer this, you need to understand the role of nitrogen-fixing bacteria in the nitrogen cycle and its impact on the ecosystem. Nitrogen-fixing bacteria are responsible for converting gaseous nitrogen into a biologically available form, making it available to plants. In their absence, plants would have to rely solely on biologically available nitrogen present in the soil, which could limit their growth and productivity. Therefore, the correct answer is C.