December 2005 LSAT
Section 1
Question 25
Almost all microbe species live together in dense, interdependent communities, supporting the environment for each ot...
Replies
Mehran on October 16, 2018
@Brandon the conclusion here is, "Thus, microbiologists lack complete knowledge of most microbe species."The support?
"Almost all microbe species live together in dense, interdependent communities, supporting the environment for each other, and regulating the population balances for their different species through a complex system of chemical signals."
"For this reason, it is currently impossible to cultivate any one such species in isolation."
This is a Strengthen with Sufficient Premise question, so we are looking for the answer choice that 100% guarantees the conclusion here.
Notice the jump in the argument. Because it is currently impossible to cultivate any one microbe species in isolation, microbiologists lack complete knowledge of most microbe species.
Now let's take a look at (C), which states:
"No microbiologist can have complete knowledge of any species of organism unless that microbiologist can cultivate that species in isolation."
This is "No As are Bs" so this sentence would be diagrammed as follows:
MCK ==> CSI
not CSI ==> not MCK
Notice that the contrapositive here closes the gap by making "impossible to cultivate any one microbe species in isolation" (not CSI) sufficient for "microbiologists lack complete knowledge" (not MCK).
As such, (C) would be the correct answer.
Hope that helps! Please let us know if you have any other questions.
Anthony-Resendes on December 15, 2020
@Mehran Maybe I missed it sir but the question at the top is about microbe species versus all species. The argument is specifically about Microbe species not any species which would normally be out of scope but for whatever reason is relevant here. Please elaborate sir.