LSAT 123 | Section 2 | Logical Reasoning: Q14

LR Question 14 Explanation

QUESTION TEXT: A cup of raw milk, after being heated in a microwave oven…

QUESTION TYPE: Weaken

CONCLUSION: Microwaves are what destroy lysozyme enzyme. Heat is not the cause.

REASONING: Heating milk to 50 degrees Celsius in a microwave destroys half the lysozyme. Heating milk to 50 degrees normally leaves almost all lysozyme intact.

ANALYSIS: This sounds like a good argument. But it’s a weaken question, so there must be something wrong with it. I couldn’t think of anything in advance on this question. When that happens, just move on the answers. But remember what you’re looking for. You’re trying to show either:

1. that heat actually is the cause, or
2. that microwaves couldn’t cause the damage.

___________

1. So? This just reinforces what we know: microwaves can destroy lysozyme. A higher heat uses more microwaves, so this answer doesn’t mean heat is the cause. It’s likely still the microwaves.
2. This tells us that we can fix the problem caused by microwave heating. But it doesn’t tell us why the problem occurs.
3. If you picked this, you probably misread it as saying “conventional heat will heat milk more slowly than a microwave does”. The answer doesn’t say that. It tells us nothing about the situation in the stimulus.
    
   Instead, this just points out something obvious: warmer heat raises temperatures faster. So what? We already knew that was true! It’s basic science.
4. Taste doesn’t matter. The argument is only about microwaves’ impact on lysozyme.
5. CORRECT. This shows that microwave heating is different from conventional heating. A 50 conventional degree heat source can’t heat higher than 50 degrees (that’s common knowledge, which the LSAT requires you to assume). So this answer means the microwave heats the milk to warmer temperature than a conventional heat source can. Therefore, it’s possible that heat is the cause after all.