BillyZ wrote:
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.
Passage summary
(i)Carotenoids acquired directly and indirectly.
(ii)Males prone to disease and parasites will use carotenoids for immunity and males that are healthy will use them for attracting females.
Question 1Quote:
According to the “conventional view” referred to in line 13 of the passage, brighter carotenoid-based coloration in certain species suggests that an individual
Context from the passage: 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.
(A) lives in a habitat rich in carotenoid-bearing plants and insects
- Nothing can be derived about the habitat of this species from the context. Eliminate A
(B) has efficient detoxification processes
- Nothing is mentioned about the efficiency of detoxification process. Eliminate B
(C) has a superior immune system
- Bright-colored species do have a superior immune system but as per the conventional view SPECIFICALLY, nothing is mentioned! Eliminate C
(D) possesses superior foraging capacity
- direct and easy reference from the context mentioned in the passage. This option is better than option C because there is direct reference to the conventional view Keep D
(E) is currently capable of reproducing
- Nothing is mentioned in the context about the reproduction. Eliminate E
Question 2Quote:
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?
Context from the passage:
(i)animal species have shown that when choosing mates, females prefer males with brighter carotenoid-based coloration.
(ii)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
(A) Inefficient detoxification processes
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Well, the passage did mention about the detoxification process but nothing is mentioned about the efficiency of the process. Eliminate A(B) Immunity to parasite infestation
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The lack of bright coloration means that the male is using carotenoids to BOOST IT'S IMMUNE SYSTEM. This option says the opposite. Eliminate B(C) Low genetic resistance to disease
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Males with bright coloration are genetically resistant. Thus, the lack of bright coloration means that males are using carotenoids for fighting the disease. They have low genetic resistance to disease. Keep C
This is a classic GMAT trick of twisting the options in a subtle way (D) Lack of interest in mating
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Nothing can be derived from the context that whether a male with a lack of bright coloration is interested in mating or not? Eliminate D(E) Lack of carotenoid-storing tissues
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No connection between carotenoid storing tissues and lack of coloration from the context. Eliminate E Question 3Quote:
The passage suggests that relatively bright carotenoid-based coloration is a signal of which of the following characteristics in males of certain animal species?
Context from the passage:
animal species have shown that when choosing mates, females prefer males with brighter carotenoid-based coloration.
(A) Readiness for mating behavior
- As per the context we can infer nothing whether a male is ready for mating? It's just the female that prefer males with bright coloration. Trap answer. Eliminate A
(B) Ability to fight
- Ability to fight what? diseases or other animals. Open-ended option there. Eliminate B
(C) Particular feeding preferences
- Not mentioned in the passage. Eliminate C
(D) Recovery from parasite infestation
- Nothing is mentioned about the recovery of males from parasite infection. Eliminate D
(E) Fitness as a mate
- Females prefer bright-colored males for mating. They are fit as a mating partner. Makes sense as per the context. Keep E
Question 4Quote:
The passage implies which of the following about the insects from which animals acquire carotenoids?
Context from the passage: 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
(A) They do not produce carotenoids themselves.
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I really love such options because they are classics GMAT twisters that GMAC tests students on!
Anyway, plants and algae themselves produce carotenoids (directly). Insects produce them indirectly. This means that insects DO NOT produce carotenoids. Insects get them from somewhere else. Keep A(B) They use carotenoids primarily for coloration.
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We don't know from the context what insects do with carotenoids. Eliminate B(C) They maintain constant levels of carotenoids in their tissues.
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we don't know this either. Eliminate C (D) They are unable to use carotenoids to boost their immune system.
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Same error as option B. Eliminate D(E) They are available in greater abundance than are carotenoid-bearing plants.
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The context tells us nothing about the number of carotenoids in insects vs plants. Eliminate E Question 5Quote:
Information in the passage suggests that which of the following is true of carotenoids that a male animal uses for detoxification processes?
Context from the passage:
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.
(A) They were not acquired directly from plants and algae.
- We cannot infer from the context whether carotenoids used for the detoxification process were acquired from plants and algae or somewhere else. Eliminate A
(B) They cannot be replenished through foraging.
- Foraging was a conventional view. No link to the detoxification process. Eliminate B
(C) They cannot be used simultaneously to brighten coloration.
- Again a classic GMAT option. There is so much to learn from this passage itself. 🙈
Males can use their SCARCE carotenoids EITHER for immune defense and detoxification OR for attracting females. This clearly tells that males can use their carotenoids for one single purpose BUT NOT simultaneously. Keep C
(D) They do not affect the animal's susceptibility to parasites.
- If a male is using its carotenoids for detoxification then that male is genetically susceptible to the parasite and disease. It is using them for boosting immunity and to become genetically resistant. Eliminate D
(E) They increase the chances that the animal will be selected as a mate.
- If males are using carotenoids for detoxification, then they WILL NOT be able to show them off for attracting females. The carotenoids are used up to boost the immune system because the males are not genetically strong. They will NOT be selected as a mate. Eliminate E