Discussion

Which one of the following, if true, most seriously weakens the argument?
(A)Heating raw milk in a microwave oven to a temperature of 100 degrees Celsius destroys nearly all of the lysozyme initially present in that milk.
(B)...
(C)...
(D)...
(E)...
(F)...
*This question is included in Sample Lesson Set 1: Basic Questions, question #7

The solution is

Posted: 07/14/2011 01:59
? Do ltge it t
Posted: 07/14/2011 14:19
This argument makes 2 claims, and then draws a conclusion:

Claim 1: Milk heated to 50 in a microwave loses half its lysozyme.

Claim 2: Milk heated to 50 in a conventional oven will not lose its lysozyme.

Conclusion: Microwaves, and NOT heat, are what destroy the lysozyme.


How can we weaken this argument? Well, we can show that heat DOES destroy lysozyme. But how would we do that?


It's not immediately clear to me, so let's look through the answer choices:

"A": This is about heating milk in a microwave, so it's not going to help us show that heat, and NOT microwaves, can destroy lysozyme. Next choice.

"B": This is totally irrelevant. Next.

"C": The speed at which a conventional heat source can heat milk to more than 50 degrees will not help us. Next.

"D": The taste of milk does not come into play in the argument. This is not our choice.

"E": If a microwave that heats a liquid to an overall temp of 50 degrees ALSO creates pockets of heat that are much hotter than 50, it's possible that the cup of raw milk heated to 50 in a microwave actually has pockets that are MUCH HOTER than 50. This is it!

If choice "E" is true, then maybe it IS the heat that is destroying the lysozyme (in the pockets that get MUCH HOTTER than 50). If this choice is true, the argument is weakened.

Posted: 08/18/2011 09:46
Thanks
Posted: 01/01/2012 08:20
I'm really not clear on this one...maybe I'm not understanding how option "e" weakens the argument
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Contributor
Posted: 01/05/2012 00:37
Ramon,

The argument says that in a Microwave, a cup of milk heated to 50 has half its lysozyme killed.

Then it says that ALMOST NONE of the lysozyme gets killed in a conventional oven heated to 50.

Then the conclusion: it must be the microwaves that kill the lysozyme, and NOT the heat.

What the conclusion is saying:
since the both the microwaved cup AND the oven-heated cup are heated to 50, heat must not be what kills the lysozyme.

But what if the milk heated in the microwave ACTUALLY got much hotter than 50?
Then it would be possible that the heat actually WAS responsible for killing the lysozyme.
If this were true, then it could actually be HEAT that kills lysozyme, and that the milk heated in the conventional over didn't reach lysozyme-killing temperature.

Now do you see how choice (E) weakens the argument?
Posted: 01/05/2012 22:51
I believe the answer should be C not E.
Here is why:
Even if the temperature can go beyond 50c in the microwave it is safe to assume that it isn't going to something crazy high like 100c. It is more likely to be 5-10c higher. Yet the difference between conventional and microwave is night and day. Unless the reader knows that at a certain temperature the effects of heat become exponential or explodes, the answer E is not a safe bet.

On the other hand we have choice C.
With C we can point the difference in effect as a result of the speed of the heating process rather than the method. This is the most reliable way assuming we don't know anything else to dismantle this argument(given these choices)

How do you guys feel.
At a certain
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Contributor
Posted: 01/09/2012 00:44
jacky,

Choice (C) only deals with conventional heat sources. The microwave oven is not discussed.

What we need to weaken the argument is an answer choice that shows that it COULD BE heat and NOT microwaves that kill the enzyme. In order to show this, the answer choice MUST make some statement that shows how microwaves and conventional ovens are different in some way that the original argument did not consider. Answer choice fails to do this.

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