ozone layer

apex231 wrote: The importance of the ozone layer to terrestrial animals is that it entirely filters out some wavelengths of light but lets others through. Holes in the ozone layer and the dangers associated with these holes are well documented. However, one danger that has not been given sufficient attention is that these holes could lead to severe eye damage for animals of many species.

Which one of the following is most strongly supported by the statements above, if they are true?

A. All wavelengths of sunlight that can cause eye damage are filtered out by the ozone layer where it is intact.

Given in question-
-Ozone entirely filters out some wavelengths of light but lets others through.
-One danger that has not been given sufficient attention is that these holes could lead to severe eye damage for animals of many species.


Now holes in ozone may cause eye damage.
Where there are no holes there is no damage.
Ozone entirely filters out some wavelengths of light but lets others through.
This means all wavelengths of sunlight that can cause eye damage are filtered out by the ozone layer otherwise they will cause eye damage - this is exactly what option A says then why is it wrong?

Can any expert reply on this?

1.ozone layer allows only some wavelength of light to pass and blocks some not all wavelength of sunlight.
2.It never says that the those light which passes through ozone do not cause eye damage.

sam2304 wrote: 1.ozone layer allows only some wavelength of light to pass and blocks some not all wavelength of sunlight.
2.It never says that the those light which passes through ozone do not cause eye damage.

I understand your point, but if there are wavelengths that pass through ozone and can cause eye damage then how is this different from a having a hole in ozone (as that can also cause eye damage by letting in wavelengths that cause eye damage)?
In this case irrespective of presence or absence of hole in ozone, eye damage can be caused.

Light can pass through ozone in two ways

1) By holes in the ozone layer
2) By passing through the ozone layer.

A rules out the possibility of 2nd but not the 1st.

happymanocha wrote:Light can pass through ozone in two ways

1) By holes in the ozone layer
2) By passing through the ozone layer.

A rules out the possibility of 2nd but not the 1st.

Yes, that's exactly the point i am trying to make. That even with ozone layer intact there are some wavelengths of that can pass through and can cause eye damage. So eye damage can occur when there is no hole and there is a hole in ozone.

So to strongly support that hole in ozone is the reason for eye damage we need to first establish that without ozone hole there is no eye damage. This can only happen when "All wavelengths of sunlight that can cause eye damage are filtered out". This is what option A states.

Hope i am making sense?

Question stem states:

Which one of the following is most strongly supported by the statements above, if they are true?

not

Which one of the following is most strongly supports the statements above, if they are true?

I think you are overlooking this piece.

happymanocha wrote:Question stem states:

Which one of the following is most strongly supported by the statements above, if they are true?

not

Which one of the following is most strongly supports the statements above, if they are true?

I think you are overlooking this piece.

Happymanocha,

I think this doesn't make any difference. We need to clearly establish that ozone holes alone cause damage to eyes.

Thanks!

Received a PM on this one...

apex231, it does more a difference actually. One type of question is a STRENGTHEN question. This is the type that you are interpreting this question to be.

However, happymanocha is correct in that the question that we are looking at here is not a strengthen question, but an INFERENCE question.

In a strengthen question you are trying to prove a conclusion, so you would indeed be trying to prove that "these holes could lead to severe eye damage for animals of many species." If this were a strengthen question then A might point us in that direction.

However, for an inference question everything in the stimulus is a fact and you are not trying to prove what is said there, but you are relying on what is said there in order to draw an inference in the answer choice. So the question here becomes, do we know for certain that "All wavelengths of sunlight that can cause eye damage are filtered out by the ozone layer where it is intact."?

No. We do not know that for certain. First of all there is the word "severe" in the stimulus and not in the answer choice. The stimulus says that holes in the ozone "could lead to severe eye damage." The answer choice says that all wavelengths that can cause "eye damage" are filtered out. This is the kind of small difference in wording that makes a big difference on these types of questions. And even if they had each said severe, we still do not know that the light that filters through has not possibility of causing any eye damage - we simply know that with holes in the ozone animals of many species will have damage. A goes beyond what we can prove and so we can eliminate it.

E is the kind of limited conclusion that we are looking for.

Now I can see why this might seem to be a strengthen question, the wording of the question is very similar. You need to track where the support goes. This question says "Which of the following IS MOST STRONGLY SUPPORTED" this means the support flows down from the stimulus to the answer choice and this makes it an inference question.