LSAT Explanation PT 31, S3, Q22: Some types of organisms originated through

LSAT Question Stem

Which one of the following is most strongly supported by the information above? 

Logical Reasoning Question Type

This is a Most Strongly supported question. 

Correct Answer

The correct answer to this question is E. 

LSAT Question Complete Explanation

The question type for this problem is Most Strongly Supported (MSS), which means we need to find the answer choice that is most strongly supported by the information provided in the passage.

First, let's break down the passage. It talks about endosymbiosis, which is when one organism engulfs another, and a part of the engulfed organism becomes a functioning part of the one that engulfed it. Think of it like a larger fish swallowing a smaller fish, and then the smaller fish helps the larger fish in some way. The passage also mentions an unusual nucleomorph (a structure containing DNA) found in a chlorarachniophyte plant. This nucleomorph has two versions of a particular gene, which suggests that it could be the remains of an engulfed organism's nucleus.

Now, let's analyze the answer choices:

a) Only organisms of types that originated through endosymbiosis contain nucleomorphs.

This answer choice is too strong because of the word "only." The passage doesn't provide enough evidence to support this claim.

b) A nucleomorph within the chlorarachniophyte holds all of the genetic material of some other organism.

This answer choice is also too strong because of the word "all." The passage only mentions that two versions of a particular gene were found, not all the genetic material of another organism.

c) Nucleomorphs originated when an organism endosymbiotically engulfed a chlorarachniophyte.

This answer choice makes a general statement about all nucleomorphs based on the information provided about one unusual nucleomorph. It exaggerates the situation and is not supported by the passage.

d) Two organisms will not undergo endosymbiosis unless at least one of them contains a nucleomorph.

This answer choice is similar to answer choice (a) and is incorrect for similar reasons. The passage doesn't establish a conditional relationship where nucleomorphs are necessary for endosymbiosis.

e) Chlorarachniophytes emerged as the result of two organisms having undergone endosymbiosis.

This answer choice is the correct one because it is most strongly supported by the passage. The unusual nucleomorph found in the chlorarachniophyte, with its two versions of a particular gene, suggests that the chlorarachniophyte could have originated through endosymbiosis.