Relevant lessons: Phenomenon-hypothesis questions | Weakening Questions
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that microwaves rather than heat kill an enzyme in milk. He bases this on the difference in enzyme concentration between milk heated in a microwave and milk heated through a conventional source.
Notable Assumptions
The author assumes that the two methods of heating—microwaves and conventional heat sources—are in all ways comparable, hence why microwaves themselves are to blame for the enzyme reduction. This means that the author doesn’t believe that some difference in the heating methods (e.g. time it takes to reach 50 degrees Celsius) accounts for the difference in enzyme concentration.
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.
We don’t care what happens at 100 degrees Celsius. We need to weaken the author’s hypothesis about milk heated to 50 degrees Celsius.
B
Enzymes in raw milk that are destroyed through excessive heating can be replaced by adding enzymes that have been extracted from other sources.
The author hypothesizes about what causes milk to lose its enzymes. We’re not interested in how those enzymes can be replenished.
C
A liquid exposed to a conventional heat source of exactly 50 degrees Celsius will reach that temperature more slowly than it would if it were exposed to a conventional heat source hotter than 50 degrees Celsius.
The stimulus talks about a heat source of 50 degrees Celsius. We’re not interested in other ranges.
D
Milk that has been heated in a microwave oven does not taste noticeably different from milk that has been briefly heated by exposure to a conventional heat source.
Taste is irrelevant. We’re talking about enzymes.
E
Heating any liquid by microwave creates small zones within it that are much hotter than the overall temperature that the liquid will ultimately reach.
While milk is heated to 50 degrees Celsius in the microwave, pockets reach higher temperatures that thus kill the enzymes. This shows that microwaves themselves don’t kill enzymes—instead, high heat does.
Relevant lessons: Referential phrasing | Phenomenon-hypothesis questions | Weakening Questions
Relevant lessons: Referential phrasing | Phenomenon-hypothesis questions | Weakening Questions
Summarize Argument: Phenomenon-Hypothesis
The scientist hypothesizes that the Earth’s warming is a result of the buildup of minor gases in the atmosphere. She bases this on the fact that such gases block the outward flow of heat away from the planet.
Notable Assumptions
Based merely on a correlation between the buildup of gases and the Earth’s warming, the scientist assumes that the former causes the latter. This means she doesn’t believe that the causal relationship is the inverse, or that there’s some hidden third factor causing both a building of gases and the Earth’s warming. The scientist also assumes a true (i.e. 1:1) correlation between the buildup of gases and the Earth’s warming over the last century, without providing data to prove such a correlation.
A
Only some of the minor gases whose presence in the atmosphere allegedly resulted in the phenomenon described by the scientist were produced by industrial pollution.
The stimulus never mentions pollution. The scientist doesn’t seem to care what caused the gases to build up in the atmosphere.
B
Most of the warming occurred before 1940, while most of the buildup of minor gases in the atmosphere occurred after 1940.
If the warming largely preceded the gas buildup, the gas buildup certainly couldn’t have caused the warming. This destroys the causation that the scientist assumes to be true.
C
Over the last century, Earth received slightly more solar radiation in certain years than it did in others.
We don’t know which years those were, or what the effects of solar radiation are. This doesn’t give us nearly enough information.
D
Volcanic dust and other particles in the atmosphere reflect much of the Sun’s radiation back into space before it can reach Earth’s surface.
The scientist doesn’t care about solar radiation.
E
The accumulation of minor gases in the atmosphere has been greater over the last century than at any other time in Earth’s history.
We don’t care about what happened in past centuries. We need to know if the buildup of gases in the last century caused the Earth’s warming.
Relevant lessons: For, since, because | Conditional logic | Sufficient assumption questions
Relevant lessons: For, since, because | Conditional logic | Sufficient assumption questions
Summarize Argument
The author argues that there are no shared values across cultures as long as there are distinct cultures. She supports this by citing anthropological evidence: distinct cultures differ in their moral codes.
Notable Assumptions
Based on the fact moral codes differ between cultures, the author assumes that no two distinct cultures share the same moral value. This means she believes that all the values contained in a moral code are unique to that moral code. She also believes that when cultures differ on moral codes, they differ entirely rather than by degree or at the margins.
A
Anthropologists rely on inadequate translation techniques to investigate the values of cultures that use languages different from the anthropologists’ languages.
The study is flawed, so any conclusions drawn from the study are questionable. Here, anthropologists might not’ve correctly identified if moral codes really differ between cultures or not.
B
As a result of advancing technology and global communication, we will someday all share the same culture and the same values.
Whether or not we all share the same culture has no bearing on distinct cultures, even if those cultures exist only as hypotheticals. Since the author concludes about distinct cultures, this doesn’t weaken.
C
Although specific moral values differ across cultures, more general moral principles, such as “Friendship is good,” are common to all cultures.
Specific values differ, but foundational values show similarities among cultures. This means that some values, in a broad sense, may be shared among cultures.
D
The anthropologists who have studied various cultures have been biased in favor of finding differences rather than similarities between distinct cultures.
Anthropologists provide flawed studies, which means we can’t draw conclusions from them. This weakens the argument, which is supported only by an anthropological study.
E
What appear to be differences in values between distinct cultures are nothing more than differences in beliefs about how to live in accordance with shared values.
Contrary to the author’s conclusion, cultures actually do share values. The differences are actually about beliefs.