Kap FL 2 - Q31 Bio

[StarFall]

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Spoiler alert: Question from Kaplan's Full length #2, Bio section



Q31: Based on information in the passage, which of the following is NOT true of Bacteroides?

Passage info: Table presented in the passage shows Bacteroides are Gram-negative.

- Bacteroides is sensitive to penicillin. Wrong answer, but I chose this answer since this answer is FALSE.
- Outside knowledge used: Penicillin works by destroying cell wall, thus works better on gram-positive strains than negative. Since gram-positive strains have cell wall on outside and gram-negative strains have an extra membrane that encloses the cell wall (so membrane is on most outer), this makes it harder for penicillin to penetrate membrane in gram-negative strains -> resistant to penicillin -> bacteroides are gram-neg so they are resistant.

http://en.wikipedia.org/wiki/Bacteroides_fragilis
States that Bacteroides are resistant (opposite of sensitive) to penicillin.

Is this a bad question, am I confusing resistance and sensitivity, or am I really not thinking straight?

 

[sazerac]

The answer key says that table 1 says that the bacterium is sensitive to penicillin. I'm just not seeing that. It doesn't really say anything at all about the subject of penicillin sensitivity. Maybe the table was modified, or cut off?

Anyway, answer A is obviously correct, B is a little fuzzy, and C and D are wrong. Go with A.

 

[NextStepTutor_1]

Agreed. If in fact the table conveys that Bacteriodes are not resist to penicillin, this is a small piece of information that does not need to be known to answer the question. Generally it's best not to chose an answer just because it's evidence is omitted (i.e. if the passage doesn't talk about it). However, if you knew that background knowledge about penicillin then I can see why B was attractive. However, here A is referred to in the passage so you're able to directly prove or disprove it's merit.

 

[StarFall]

The answer key says that table 1 says that the bacterium is sensitive to penicillin. I'm just not seeing that. It doesn't really say anything at all about the subject of penicillin sensitivity. Maybe the table was modified, or cut off?

Anyway, answer A is obviously correct, B is a little fuzzy, and C and D are wrong. Go with A.

Agreed. If in fact the table conveys that Bacteriodes are not resist to penicillin, this is a small piece of information that does not need to be known to answer the question. Generally it's best not to chose an answer just because it's evidence is omitted (i.e. if the passage doesn't talk about it). However, if you knew that background knowledge about penicillin then I can see why B was attractive. However, here A is referred to in the passage so you're able to directly prove or disprove it's merit.

I can see why A is correct since it's mentioned in the passage, but how would you eliminate B as a wrong answer (true concept of Bacteroides)?
More evidence/passage correlation for A than B?
It seems like the table for this question is wrong or Kaplan meant to put resistant instead of sensitive.

 

[sazerac]

I bet the table is wrong.