Carotenoids, a family of natural pigments, form an important part of

Question

Carotenoids, a family of natural pigments, form an important part of the colorful signals used by many animals. Animals acquire carotenoids either directly (from the plants and algae that produce them) or indirectly (by eating insects) and store them in a variety of tissues. Studies of several animal species have shown that when choosing mates, females prefer males with brighter carotenoid-based coloration. Owens and Olson hypothesize that the presence of carotenoids, as signaled by coloration, would be meaningful in the context of mate selection if carotenoids were either rare or required for health. The  conventional view  is that carotenoids are meaningful because they are rare: healthier males can forage for more of the pigments than can their inferior counterparts. Although this may be true, there is growing evidence that carotenoids are meaningful also because they are required: they are used by the immune system and for detoxification processes that are important for maintaining health. It may be that males can use scarce carotenoids either for immune defense and detoxification or for attracting females. Males that are more susceptible to disease and parasites will have to use their carotenoids to boost their immune systems, whereas males that are genetically resistant will use fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead.   1 
 RC00423-01 
 1. According to the “ conventional view ” referred to in line 13 of the passage, brighter carotenoid-based coloration in certain species suggests that an individual

(A) lives in a habitat rich in carotenoid-bearing plants and insects
(B) has efficient detoxification processes
(C) has a superior immune system
(D) possesses superior foraging capacity
(E) is currently capable of reproducing

2 
 RC00423-02 
 2. The idea that carotenoid-based coloration is significant partly because carotenoids are required for health suggests that a lack of bright coloration in a male is most likely to indicate which of the following?

(A) Inefficient detoxification processes
(B) Immunity to parasite infestation
(C) Low genetic resistance to disease
(D) Lack of interest in mating
(E) Lack of carotenoid-storing tissues

3 
 RC00423-03 
 3. The passage suggests that relatively bright carotenoid-based coloration is a signal of which of the following characteristics in males of certain animal species?

(A) Readiness for mating behavior
(B) Ability to fight
(C) Particular feeding preferences
(D) Recovery from parasite infestation
(E) Fitness as a mate

4 
 RC00423-04 
 4. The passage implies which of the following about the insects from which animals acquire carotenoids?

(A) They do not produce carotenoids themselves.
(B) They use carotenoids primarily for coloration.
(C) They maintain constant levels of carotenoids in their tissues.
(D) They are unable to use carotenoids to boost their immune system.
(E) They are available in greater abundance than are carotenoid-bearing plants.

5 
 RC00423-05 
 5. Information in the passage suggests that which of the following is true of carotenoids that a male animal uses for detoxification processes?

(A) They were not acquired directly from plants and algae.
(B) They cannot be replenished through foraging.
(C) They cannot be used simultaneously to brighten coloration.
(D) They do not affect the animal's susceptibility to parasites.
(E) They increase the chances that the animal will be selected as a mate.

ISSUE 2223  | MAGAZINE COVER DATE: 29 January 2000

https://www.newscientist.com/article/mg16522234-300-shes-gotta-have-it/

GMATNinja · Accepted Answer

Question 2 
 
Question 2 asks us which answer choice is most likely indicated by "a lack of bright coloration in a male" based on the idea that carotenoids are required for health.

The key to eliminating (A) is in the exact wording of the answer choice:
 
You are right that the passage mentions using carotenoids for detoxification processes, but what does it say about the  efficiency  of these processes? To answer this, look at the evidence stated in the passage:
 
This evidence tells us that some males have to use more carotenoids to boost their immune systems because they are more susceptible to disease and parasites. In other words, some males have to expend their carotenoids on immunity and detoxification because they are more likely to acquire a disease/parasite than other males.

What this does  not  tell us is  how efficient  the detoxification processes for either type of male is after they already acquired a disease/parasite. The drab males could have detoxification processes  just as efficient  as their flashy counterparts, but still use more carotenoids to boost their immunity because they are more susceptible to disease/parasites in the first place.

Because of the above reasoning, we cannot conclude that "a lack of bright coloration in a male is most likely to indicate" that those males have " inefficient  detoxification processes." (A) is not the answer to question 2.

As you point out, the evidence in support of (C) is clear: the passage states that "males that are  genetically resistant  will use fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead." So, we can easily infer that a lack of bright coloration indicates "low genetic resistance to disease." (C) is the correct answer.

Valhalla · Answer

Thanks for the upload.

Please comment on explanations, as I managed only to complete reading comprehension in 11:11.
Passage Analysis:
Tone: Explains / Descriptive
Organization:
Describe carotenoids usage in animals - 2 schools of thoughts  .

1. Inference:
The conventional view is that carotenoids are meaningful because they are rare: healthier males can forage for more of the pigments than can their inferior counterparts.
ANS: D possesses superior foraging capacity : healthier males can forage for more of the pigments than can their inferior counterparts.

2. Inference:
Although this may be true, there is growing evidence that carotenoids are meaningful also because they are required: they are used by the immune system and for detoxification processes that are important for maintaining health.
Males that are more susceptible to disease and parasites will have to use their carotenoids to boost their immune systems, whereas males that are genetically resistant will use fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead.
ANS: C Low genetic resistance to disease : males that are genetically resistant will use fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead.

3. Inference
Studies of several animal species have shown that when choosing mates, females prefer males with brighter carotenoid-based coloration.
ANS: E Fitness as a mate : Studies of several animal species have shown that when choosing mates, females prefer males with brighter carotenoid-based coloration.

4. Inference
Animals acquire carotenoids either directly (from the plants and algae that produce them) or indirectly (by eating insects) and store them in a variety of tissues. 
ANS: A They do not produce carotenoids themselves (obtain via POE + insect = animal, therefore if these animals / insects obtained carotenoids from plants / insects, therefore these animals / insects cannot themselves produce carotenoids) - Experts please help on Q4

5. Inference
It may be that males can use scarce carotenoids either for immune defense and detoxification or for attracting females. 
ANS: C They cannot be used simultaneously to brighten coloration : Because of the word OR

Kudos and constructive comments are appreciated. Thanks

GMATNinja · Answer

Passage breakdown

In passages that are one, long paragraph, it can be helpful to split the passage up. In this explanation, the passage will be split into three sections:

Section 1: from the start to “...if carotenoids were either rare or required for health.” 
 Section 2: from “The conventional view is that...” to “...their inferior counterparts” 
 Section 3: from “Although this may be true...” to the end of the passage.

In the first section, the author  introduces an animal behavior and provides two potential reasons for that behavior.

The behavior: "females prefer males with brighter carotenoid-based coloration." 
 Two potential reasons for this behavior: carotenoids are  either rare or required.

In the second section, the author  outlines the conventional view.

This view holds that carotenoids are meaningful because they are  rare .

In the third section, the author  argues that, while the conventional view may be true, the other potential explanation is ALSO true.

The author states that "there is growing evidence that carotenoids are meaningful also because they are  required ." 
 He/she then provides details to support this claim.

For more on the process of breaking down RC passages, check out  this article  and  our live RC videos .

Masterscorp · Answer

Question 5 is the hardest one imo:

RC00423-05
5. Information in the passage suggests that which of the following is true of carotenoids that a male animal uses for detoxification processes?

(A) They were not acquired directly from plants and algae.  carotenoids can be acquired from plants or insects and we don't have any info about whether there are different uses of the carotenoids from both sources 
(B) They cannot be replenished through foraging.  If animals use the sources mentioned above they can replenish carotenoids 
(C) They cannot be used simultaneously to brighten coloration.  This is mentioned in the passage. "It may be that males can use scarce carotenoids either for immune defense and detoxification or for attracting females". Yes, it says maybe, but it is the best out of all answers. 
(D) They do not affect the animal's susceptibility to parasites.  Carotenoids can be used to bolster the immune system, hence this answer is incorrect 
(E) They increase the chances that the animal will be selected as a mate.  It actually weakens the chances because carotenoids used for detoxification can't be used to increase brightness, leadiing to a higher chance of mating

NandishSS · Answer

HI  GMATNinja  ,  mikemcgarry  ,  egmat  ,  sayantanc2k ,  RonPurewal  ,  DmitryFarber  ,  MagooshExpert  (Carolyn),  ccooley  ,  GMATNinja Two ,  SarahPurewal  ,  EMPOWERgmatVerbal

Here is the relavent part but how to infer?

Animals acquire carotenoids either directly (from the plants and algae that produce them) or indirectly (by eating insects) and store them in a variety of tissues.

4. The passage implies which of the following about the insects from which animals acquire carotenoids?

(A) They do not produce carotenoids themselves.
(B) They use carotenoids primarily for coloration.
(C) They maintain constant levels of carotenoids in their tissues.
(D) They are unable to use carotenoids to boost their immune system.
(E) They are available in greater abundance than are carotenoid-bearing plants.

Gagoosh · Answer

I was thinking the same thing, but took clue from the information from within the brackets. Acquire directly (....that produce them) or indirectly (..eating insects). Infered that plants can produce them (animal consuming the plants that DIRECTLY produce carotenoids) and insects cannot produce carotenoids (animals acquiring carotenoids from insects, which in turn might be eating those plants, hence INDIRECTLY).

Await expert's view though.

teaserbae · Answer

GMATninja2   workout   broall   Gnpth  
Can you please explain in q4 how it is inferred ?

Nikhil · Answer

teaserbae

The answer lies in the following lines

"Animals acquire carotenoids either directly (from the plants and algae that produce them) or indirectly (by eating insects) and store them in a variety of tissues. "

Now what can we infer about the insects ?

Animals either acquire carotenoids from plant or by eating insects. These insects which come under the classification of animals again must have acquired carotenoids through plants or by eating some other insects. Hence these insects didnot produce the carotenoids themselves and that is what option A states.

JS1290 · Answer

Hi  GMATNinja ,

I was wondering could you please explain why option A is incorrect for Q2? The passage states that carotenoids are used "by the immune system for detoxification processes". It is also given that "males can use scarce carotenoids either for immune defense and detoxification or for attracting females". Based on this, can't we infer that a lack of bright coloration means that the carotenoids were used by the immune system or rather the detoxification was inefficient? I understand why option C is correct because we are strictly told about this option in the last line of our paragraph; however, I am unable to see the true reasoning behind why option A is incorrect.

If you could please share your thoughts behind it, I would immensely appreciate it!

aha · Answer

About Q.5
I followed your attached link and read your post. It seems like that unlike the healthy males, weak males cannot use carotenoids for two purposes at the same time.
Am I right?

GMATNinja · Answer

Take another look at the exact wording of question #5:
 
This question is asking specifically about "carotenoids that a male animal uses for detoxification processes." So, we know that the exact carotenoids in question have already been allocated for detoxification.

Out of all of the carotenoids that a given male bird can scrounge up, he will use some amount for his immune system/detoxification and some amount for coloration. A bird that is "more susceptible to disease and parasites" has to use his carotenoids to boost his immune system, while a more resistant bird will use "fewer carotenoids for fighting disease and will advertise this by using the pigments for flashy display instead."

In either case, if a carotenoid has already been used for detoxification processes, that  exact  carotenoid  cannot also be used to brighten the bird's coloration . This is true for both healthy and unhealthy birds. So, carotenoids that a male animal uses for detoxification processes "cannot be used simultaneously to brighten coloration." (C) is the correct answer for question #5.

I hope that helps!

zoezhuyan · Answer

Dear  GMATNinja

I struggle between D and E, I chose D because the statement " "
Does not it imply that recovered from carotenoids?

Please help.

GMATNinja · Answer

Bright carotenoid-based coloration might indicate a strong immune system and, thus, an  ability  to recover well from a parasite infestation. But bright carotenoid-based coloration does NOT indicate that the animal IS recovering from parasite infestation. The coloration is a sign that the male is fit as a mate, not that the male is  actively  recovering from an illness or infection.

In other words, you cannot point to male with bright carotenoid-based coloration and say, "oh, that male must be recovering from a parasite infestation right now."

I hope that helps!

zoezhuyan · Answer

Dear  GMATNinja , I am little confused. if the bird did not allocate all carotenoids for detoxification? I read the passage and #5 many times, I cannot figure out where tells all carotenoids are used for detoxification. if not all used for detoxification, it is possible that some amount will be used for coloration.

please help further.

thanks in advance

GMATNinja · Answer

The key in this portion:

This "scarce" resource, carotenoids, can be used either for immune defense/detox OR for attracting females. If you are susceptible to disease/parasites, you'll have to use your carotenoids to boost your immune system, leaving LESS of your carotenoid supply for coloration.

The main idea is that, with a limited supply of carotenoid, you have to choose how to allocate those carotenoids--do you want to use it all to boost your immune system? All for coloration? Some combination of the two? If you only have a fixed amount of carotenoids, you cannot simultaneously use ALL of your carotenoids to boost your immune AND use ALL of your carotenoids for coloration. Instead, you have to budget some amount for each purpose.

Sure, it is POSSIBLE that your supply of carotenoids is so large that you have enough to take care of your immune system and enough for coloration. But, according to the passage, birds that are more susceptible to disease/parasites will have less available for coloration.

Remember, we do not need to PROVE that choice (C) is true. The passage just has to SUGGEST that it is true.

I hope that helps!

Nonktp · Answer

GMATNinja  I'm not clear about question 3
I was considering choice A and choice E. But, I chose A. Could you please help clarify why choice E is the correct one ?
Appreciate your help.

GMATNinja · Answer

Consider this quote from the passage:

"Studies of several animal species have shown that when choosing mates, females prefer males with brighter carotenoid-based coloration."

In other words, a male’s bright, carotenoid-based coloration makes it a more desirable mate for females.

Now, let’s take a look at (A) and (E) to see if we can find a reason to eliminate each answer choice. Here’s (A):

So, does the passage suggest that bright, carotenoid-based coloration signals that an animal is READY to mate? It definitely suggests that such coloration signals a DESIRABLE mate, but that is different than being READY for mating behavior. In other words, an animal could be a desirable mate but still not be ready to mate. Eliminate (A).

And here’s (E):

You could claim the passage doesn’t mention the fitness as a mate of an animal with bright, carotenoid-based coloration, but the question asks what the passage suggests. The passage makes clear that females prefer bright coloration when choosing a mate. Presumably, that coloration is indicative of a male’s fitness as a mate. Otherwise, females would not prefer it. With that in mind, (E) is the correct answer to question 3.

I hope that helps!

Sahils57 · Answer

In Question 1.

According to the passage, per the conventional view brighter carotenoid-based coloration in certain  Males  would suggest that those males posses superior foraging capacity. But this question is not about a few certain males. This question is about . If the whole species has brighter carotenoid-based coloration wouldn't that mean that no individual has the superior foraging capacity? I chose D and then got confused by the wording of the question and ended up choosing A. To me the passage does not provide enough info to answer this question.

GMATNinja  could you help me out with my thought process. I know I'm reading too much into the question, but that's what the whole exam is I suppose.

GMATNinja · Answer

Question 1 
 
It's important to note that the question is framed in terms of the  conventional view . What does the conventional view say? It says that males who are better foragers can signal their superior ability to others because they will eat more carotenoids and have brighter colors. So the question is asking what it means if an individual within a species has brighter colors  according to the conventional view.

Before diving into the answer choices, it's helpful to note that the passage presents an alternative view to the conventional view. The passage states that there's evidence that brighter colors signal information about detoxification and the immune system.

In addition, take another look at the entire stem for question 1:
 
What does the word "in" mean here? It could mean the entire species has brighter coloration. But then what would the reference to the individual be about? A better interpretation is that the question is asking about an individual with brighter coloration   within  a species that experiences carotenoid-based coloration . So, the question doesn't ask about the species as a whole -- instead, it asks about certain individuals who have brighter coloration.

With all of that background, we should be ready to move through the answer choices.

This answer choice might be interesting if we were talking about entire species. But, as discussed above, the question is about  individuals  within species. And the conventional view is about individuals having superior foraging abilities -- not about the levels of carotenoid-bearing plans and insects in a particular habitat. So we can eliminate answer choice (A).

The passage discusses detoxification. However, it's the second view, not the conventional view, that says that detoxification is important. The question is about the conventional view, so answer choice (B) is out.

Similar to answer choice (B), the passage does discuss the immune system, but this is associated with the second view, not the conventional view, so we can eliminate this answer choice.

This is exactly what the conventional view is about: brighter coloration demonstrates superior foraging abilities. We'll leave answer choice (D) in.

The conventional view implicitly touches on reproduction because the brighter colored males send a signal to females. But what is the signal? That the brighter colored males are better foragers. There's no indication that the signal is that the brighter colored males are  capable  of reproducing. So answer choice (E) is out.

That leaves us with answer choice (D) as the correct answer.

I hope that helps!

Carotenoids, a family of natural pigments, form an important part of

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GMAT Reading Comprehension (RC) Questions

Carotenoids, a family of natural pigments, form an important part of

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