Background: In many ways, bacterial metabolism provides traits that are useful for ecological stability and for human society. One example is that some bacteria have the ability to fix nitrogen gas using the enzyme nitrogenase. This environmentally important trait can be found in bacteria of most metabolic types listed above. This leads to the ecologically important processes of denitrification, sulfate reduction, and acetogenesis, respectively. Bacterial metabolic processes are also important in biological responses to pollution; for example, sulfate-reducing bacteria are largely responsible for the production of the highly toxic forms of mercury (methyl- and dimethylmercury) in the environment. Non-respiratory anaerobes use fermentation to generate energy and reducing power, secreting metabolic by-products (such as ethanol in brewing) as waste. Facultative anaerobes can switch between fermentation and different terminal electron acceptors depending on the environmental conditions in which they find themselves.

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read more about denitrification?
Answer: Scott

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read less about denitrification?
Answer: Brett

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read less about sulfate reduction?
Answer: Brett

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read more about sulfate reduction?
Answer: Scott

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read more about acetogenesis?
Answer: Scott

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read less about acetogenesis?
Answer: Brett

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read less about the production of the highly toxic methylmercury?
Answer: Brett

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read more about the production of the highly toxic methylmercury?
Answer: Scott

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read more about the production of the highly toxic dimethylmercury?
Answer: Scott

Situation: Brett and Scott were both studying bacteria for their exam. Scott read more about nitrogen-fixating and sulfate-reducing bacteria, while his colleague Brett read more about non-respiratory anaerobe bacteria and facultative anaerobes.

Question: Which student read less about the production of the highly toxic dimethylmercury?
Answer: Brett

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned more about the enzyme nitrogenase?
Answer: Bob

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned less about the enzyme nitrogenase?
Answer: Andy

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned less about denitrification?
Answer: Andy

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned more about denitrification?
Answer: Bob

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned more about sulfate reduction?
Answer: Bob

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned less about sulfate reduction?
Answer: Andy

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned less about acetogenesis?
Answer: Andy

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned more about acetogenesis?
Answer: Bob

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned more about fermentation to generate energy?
Answer: Andy

Situation: Bob and Andy are two microbiologists.  They are studying bacteria: Bob studies nitrogen fixating bacteria, while Andy studies non-respiratory and facultative anaerobes.

Question: Which researcher learned less about fermentation to generate energy?
Answer: Bob

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had more bacteria that used the enzyme nitrogenase?
Answer: region A

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had fewer bacteria that used the enzyme nitrogenase?
Answer: region B

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had less denitrification?
Answer: region B

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had more denitrification?
Answer: region A

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had more sulfate reduction?
Answer: region A

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had less sulfate reduction?
Answer: region B

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had less acetogenesis?
Answer: region B

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had more acetogenesis?
Answer: region A

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had more bacteria which use fermentation to generate energy?
Answer: region A

Situation: Two regions, region A and region B, shared a common border, a river. Region A was favorable for sulfate-reducing bacteria and nitrogen fixing bacteria, while region B was more favorable for the developement of Non-respiratory anaerobes and facultative anaerobes.

Question: Which region had fewer bacteria which use fermentation to generate energy?
Answer: region B