LSAT Explanation PT 45, S4, Q5: Rats fed high doses of the

LSAT Question Stem

Which one of the following, if true, does the most to resolve the apparent discrepancy in the information above? 

Logical Reasoning Question Type

This is a Paradox question. 

Correct Answer

The correct answer to this question is A. 

LSAT Question Complete Explanation

First, let's break down the passage and understand the paradox presented. The passage tells us that rats fed high doses of saccharin develop silicate crystals, which are toxic to cells lining the bladder, and eventually lead to bladder cancer. However, mice fed high doses of saccharin do not get bladder cancer. The paradox here is that both rats and mice are fed high doses of saccharin, but only rats develop bladder cancer.

To better understand this, let's use a simple example. Imagine a group of people who eat a particular type of candy and experience toothaches, while another group of people who eat the same candy do not experience toothaches. The paradox would be that both groups consume the same candy, but only one group experiences toothaches.

Now, let's analyze the answer choices and determine which one best resolves the discrepancy in the passage.

a) Urine proteins that react with saccharin to form silicate crystals are found in rats but not in mice.

This answer choice resolves the paradox by explaining that rats have a specific urine protein that reacts with saccharin to form the toxic silicate crystals, which are not present in mice. This difference between the two species could be the reason why only rats develop bladder cancer when fed high doses of saccharin.

b) Cells in the bladder regenerate more quickly in mice than they do in rats.

While this answer choice presents a difference between rats and mice, it does not directly address the discrepancy in the passage. Faster regeneration in mice might not necessarily prevent the formation of silicate crystals or cancerous cells, and the answer choice does not provide enough information to explain why mice do not develop bladder cancer.

c) High doses of saccharin are much more likely to produce silicate crystals than lower doses are.

This answer choice does not resolve the paradox, as it only provides information about the relationship between saccharin dosage and crystal formation. It does not explain why mice do not develop bladder cancer when fed high doses of saccharin.

d) The silicate crystals are toxic only to the cells lining the bladder and not to other bladder cells.

This answer choice explains the specific effect of silicate crystals, but it does not address the discrepancy in the passage. It does not explain why mice do not develop bladder cancer when fed high doses of saccharin, even though they have the same cells lining their bladder.

e) High doses of other artificial sweeteners have been shown to produce silicate crystals in mice but not in rats.

This answer choice presents a difference between rats and mice regarding other artificial sweeteners, but it does not address the discrepancy in the passage. We are trying to explain why high doses of saccharin cause bladder cancer in rats but not in mice, and this answer choice does not provide any information about saccharin.

In conclusion, the correct answer choice is (a), as it provides a clear explanation for the discrepancy in the passage by highlighting a difference between rats and mice that could account for the different outcomes when fed high doses of saccharin.