1. A- Role of iron binding agents is not the primary purpose.
B- New treatments are never mentioned. Illogical.
C- Yes, the function of fever and temperature rises is what is mainly talked about.
D- Constant temperature is opposite to what is actually talked about.
E- Is just a part, and not the primary purpose.

2. A- Serum iron production is not mentioned in the experiment.
B- Warm blooded experiments have not been carried out. Incorrect.
C- Totally irrelevant.
D- Correct as this is mentioned in the line "microbial synthesis of siderophores—substances that bind iron—in bacteria of the genus Salmonella declined at environmental temperatures above 37℃ and stopped at 40.3℃."
E- Trap answer. The bacteria is not of salmonella but attacking it. Also we don't know if the iron is used as a nutrient.

3. A- True because the passage mentions "Cold-blooded animals were used to test this hypothesis because their body temperature can be controlled in the laboratory". From this it can be inferred warm blooded animals' temperatures are harder to control in a lab.
B- No info to infer any of this.
C- This is true for iguana's, who are cold blooded.
D- Just an amalgam of incorrect info.
E- No such pattern is mentioned.

4. A- If body temperature is lowered then iron production will increase and this means production of bacteria will also increase.
B- This will increase bacteria. Opposite of being treated.
C- Correct. If serum iron is unavailable, the bacteria won't be able to bind.
D- Reduced iron diets might work but it is not the most effective treatment.
E- This only works for iguana's. Not sure if applicable to warm blooded creatures.

This is the key relationship that makes C the best answer

The other answers are out of scope or not mentioned in the passage.

Hope now is clear.

Ask if you need further assistance.

My guess -

C
D
A
C

Please share the answer explanation for question 4.

if serum iron level falls during infection, why are we administering a medication that makes serum iron "unavailable " to the bacteria

Hey,

Here is the explanation for Q3.

https://gre.myprepclub.com/forum/warm-bloo ... tml#p54454

The last question is a bit confusing between C and D. But C is stronger. So, correct.

1. The passage is primarily concerned with attempts to determine

(A) the role of siderophores in the synthesis of serum iron

This is mentioned but is not the primary purpose of the passage

(B) new treatments for infections that are caused by A. hydrophilia

No.

(C) the function of fever in warm-blooded animals

Yes. The entire passage is dedicated to answering the questions -"Why then during sickness should temperature rise, apparently increasing stress on the infected organism?

(D) the mechanisms that ensure constant body temperature

The passage is not interested in the mechanisms that maintain constant body temperature.

(E) iron utilization in cold-blooded animals

No.



2. According to the passage, Garibaldi determined which of the following?

(A) That serum iron is produced through microbial synthesis.

No.

(B) That microbial synthesis of siderophores in warm-blooded animals is more efficient at higher temperatures.

No. It is the other way around. He discovered that the microbial synthesis of siderophores in warm-blooded animals is inefficient at higher temperatures.

(C) That only iron bound to other substances can be used by bacteria.

No.

(D) That there is a relationship between the synthesis of siderophores in bacteria of the genus Salmonella and environmental temperature.

Yes. He found that microbial synthesis of siderophores—substances that bind iron—in bacteria of the genus Salmonella declined at environmental temperatures above 37°C and stopped at 40.3°C.

(E) That bacteria of the genus Salmonella require iron as a nutrient.

It is not mentioned in the passage that he determined that bacteria of the genus Salmonella require iron as a nutrient.


3. Which of the following can be inferred about warm-blooded animals solely on the basis of information in the passage?

(A) The body temperatures of warm-blooded animals cannot be easily controlled in the laboratory.

Yes. The following sentences in the passage reveal this - "Cold-blooded animals were used to test this hypothesis because their body temperature can be controlled in the laboratory."

(B) Warm-blooded animals require more iron in periods of stress than they do at other times.

Not mentioned in the passage.

(C) Warm-blooded animals are more comfortable at an environmental temperature of 37°C than they are at a temperature of 42°C.

Not mentioned in the passage.

(D) In warm-blooded animals, bacteria are responsible for the production of siderophores, which, in turn, make iron available to the animal.

Not mentioned in the passage. The bacteria, according to the passage synthesize siderophores which bind iron for their own consumption and not the animal.

(E) In warm-blooded animals, infections that lead to fever are usually traceable to bacteria.

Not mentioned in the passage.


4. If it were to be determined that “similar phenomena occur in warm-blooded animals”, which of the following, assuming each is possible, is likely to be the most effective treatment for warm-blooded animals with bacterial infections?

What are the similar phenomena? It is the reduction in mortality rates at higher temperatures in iguanas reversed when iron solution was injected. Therefore, since injection of iron solution (which increases availability of iron to A.hydrophilia) plays a crucial role in increasing mortality rates, the most effective treatment for warm-blooded animals would be a method which denies iron availability to the bacteria.

(A) Administering a medication that lowers the animals’ body temperature

Assuming it is possible to lower the body temperature of a warm-blooded animal without affecting its health, no, it is not the most effective treatment. It will improve the bacteria's ability to intake iron and thus increase the intensity of sickness in the animal.

(B) Injecting the animals with an iron solution

No. It will improve the bacteria's ability to intake iron and thus increase the intensity of sickness in the animal.

(C) Administering a medication that makes serum iron unavailable to bacteria

Yes. This will deny iron to the bacteria, prevent it from multiplying, and thus reduce the infection.

(D) Providing the animals with reduced-iron diets

Not the most effective.

(E) Keeping the animals in an environment with temperatures higher than 37°C

No, since it is a warm-blooded animal, this may not be possible.

My guess:

C
D
A
A

Added the OA guys.

Ask if something is unclear to you.

Regards

Why is the answer to the last question C?

please explain question no 3 and 4

Can you brief me with options ( C ) and ( D ) of Q4….
Thank you

For anyone confused by 27, from what I understand, the body increases its temperature so that it prevents the production of the siderophobes and prevents the bacteria from getting iron; furthermore, the increase in iron causes an increase in mortality so this is evidence that increasing the concentration of iron can counteract the effect of reducing siderophobes/iron binding. So the root of the problem is the bacteria binding (even at high temperatures, it is not completely stopped). Now, I could see either C or D working for 28 but it is much more effective to tackle the root of the problem (bacteria binding to the iron) than to give a low-iron diet, so I put D. E is a tricky choice because we know that the production of Salmonella stops around 40.3 degrees and the experiment on iguanas was done at 42 degrees, so it is not easy to say if any temperature greater than 37 degrees would be okay.

I got 26 wrong too because I was only looking at the first line "Warm-blooded animals have elaborate ... controls to maintain constant body temperature". I was thinking, this does not necessarily mean that warm-blooded animals' temperature cannot be easily controlled! But if we look at lines 13-15, it says that "Cold-blooded animals were used ... because their body can be controlled ...". The word "because" infers that warm-blooded animals may be harder to control.

However, I think C could be a possible answer because it says that "healthy animals prefer the lower temperature". It doesn't specify that warm-blooded or cold-blooded animals prefer it, so I believe it is speaking about both?!

Q3


Cold-blooded animals were used to test this hypothesis because their body temperature can be controlled in the laboratory.

From this sentence we can easily infer that the warm-blood animal temperature is not easily controlled under testing or laboratory


Which of the following can be inferred about warm-blooded animals solely on the basis of information in the passage?

(A) The body temperatures of warm-blooded animals cannot be easily controlled in the laboratory.
(B) Warm-blooded animals require more iron in periods of stress than they do at other times.
(C) Warm-blooded animals are more comfortable at an environmental temperature of 37℃ than they are at a temperature of 42℃.

Cold-blooded animals were used to test this hypothesis because their body temperature can be controlled in the laboratory. Kluger reported that of iguanas infected with the potentially lethal bacterium A. hydrophilia, more survived at temperatures of 42℃ than at 37℃, even though healthy animals prefer the lower temperature.

C mentioned that warm-bllod animal were more used to at a temperature of 42C but those animals were the COLD-blood. Those used for the testing.

No where in the passage C is mentioned.


(D) In warm-blooded animals, bacteria are responsible for the production of siderophores, which, in turn, make iron available to the animal.
(E) In warm-blooded animals, infections that lead to fever are usually traceable to bacteria.





Q27
I think you overthinking the scenario

The key phrase is the following

Thus, fever would make it more difficult for an infecting bacterium to acquire iron and thus to multiply

Moreover, the passage suggests this

Cold-blooded animals were used to test this hypothesis because their body temperature can be controlled in the laboratory.

So C is the answer

For question 26, I was looking here when I got the evidence:
Kluger reported that of iguanas infected with the potentially lethal bacterium A. hydrophilia, more survived at temperatures of 42° C than at 37° C, even though healthy animals prefer the lower temperature.

@Carcass, wouldn't you say that "prefer" has the same kind of meaning as "comfortable"?

To be honest Sir I usually do not infer that much.

prefer= comfortable....it is not properly the same.

I prefer pizza rather than pasta. Am I comfortable ?' mhhhh far-fetched

I prefer to lay on the coach than bed....I am more comfortable on the former. Could be...

It depends.

Bottom line: DO NOT infer too much or try to find a meaning which goes too far. Stay tight to the passage I.E. Do not think too much


Regards