Species interdependence in nature confers many benefits on the species

Question

Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when one species involved in the relationship is affected by a catastrophe. Thus, flowering plant species dependent on insect pollination, as opposed to self-pollination or wind pollination, could be endangered when the population of insect-pollinators is depleted by the use of pesticides.

In the forests of New Brunswick, for example, various pesticides have been sprayed in the past 25 years in efforts to control the spruce budworm, an economically significant pest. Scientists have now investigated the effects of the spraying of Matacil, one of the anti-budworm agents that is least toxic to insect-pollinators. They studied Matacil’s effects on insect mortality in a wide variety of wild insect species and on plant fecundity, expressed as the percentage of the total flowers on an individual plant that actually developed fruit and bore seeds. They found that the most pronounced mortality after the spraying of Matacil occurred among the smaller bees and one family of flies, insects that were all important pollinators of numerous species of plants growing beneath the tree canopy of forests. The fecundity of plants in one common indigenous species, the red-osier dogwood, was significantly reduced in the sprayed areas as compared to that of plants in control plots where Matacil was not sprayed. This species is highly dependent on the insect-pollinators most vulnerable to Matacil. The creeping dogwood, a species similar to the red-osier dogwood, but which is pollinated by large bees, such as bumblebees, showed no significant decline in fecundity. Since large bees are not affected by the spraying of Matacil, these results add weight to the argument that spraying where the pollinators are sensitive to the pesticide used decreases plant fecundity.

The question of whether the decrease in plant fecundity caused by the spraying of pesticides actually causes a decline in the overall population of flowering plant species still remains unanswered. Plant species dependent solely on seeds for survival or dispersal are obviously more vulnerable to any decrease in plant fecundity that occurs, whatever its cause. If, on the other hand, vegetative growth and dispersal (by means of shoots or runners) are available as alternative reproductive strategies for a species, then decreases in plant fecundity may be of little consequence. The fecundity effects described here are likely to have the most profound impact on plant species with all four of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species.  Perhaps we should give special attention to the conservation of such plant species since they lack key factors in their defenses against the environmental disruption caused by pesticide use.    1 
 1. Which of the following best summarizes the main point of the passage?

(A) Species interdependence is a point of weakness for some plants, but is generally beneficial to insects involved in pollination.
(B) Efforts to control the spruce budworm have had deleterious effects on the red-osier dogwood.
(C) The used of pesticides may be endangering certain plant species dependent on insects for pollination.
(D) The spraying of pesticides can reduce the fecundity of a plant species, but probably does not affect its overall population stability.
(E) Plant species lacking key factors in their defenses against human environmental disruption will probably become extinct.

2 
 2. According to the author, a flowering plant species whose fecundity has declined due to pesticide spraying may not experience an overall population decline if the plant species can do which of the following?

(A) Reproduce itself by means of shoots and runners.
(B) Survive to the end of the growing season.
(C) Survive in harsh climates.
(D) Respond to the fecundity decline by producing more flowers.
(E) Attract large insects as pollinators.

3 
 3. The passage suggests that the lack of an observed decline in the fecundity of the creeping dogwood strengthens the researchers conclusions regarding pesticide use because the

(A) creeping dogwood is a species that does not resemble other forest plants
(B) creeping dogwood is a species pollinated by a broader range of insect species than are most dogwood species
(C) creeping dogwood grows primarily in regions that were not sprayed with pesticide, and so served as a control for the experiment
(D) creeping dogwood is similar to the red-osier dogwood, but its insect pollinators are known to be insensitive to the pesticide used in the study
(E) geographical range of the creeping dogwood is similar to that of the red-osier dogwood, but the latter species relies less on seeds for reproduction

4 
 4. The passage suggests that which of the following is true of the forest regions in New Brunswick sprayed with most anti-budworm pesticides other than Matacil?

(A) The fecundity of some flowering plants in those regions may have decreased to an even greater degree than in the regions where Matacil is used.
(B) Insect mortality in those regions occurs mostly among the larger species of insects, such as bumblebees.
(C) The number of seeds produced by common plant species in those regions is probably comparable to the number produced where Matacil is sprayed.
(D) Many more plant species have become extinct in those regions than in the regions where Matacil is used.
(E) The spruce budworm is under better control in those regions than in the regions where Matacil is sprayed.

5 
 5. It can be inferred that which of the following is true of plant fecundity as it is defined in the passage?

(A) A plant’s fecundity decreases as the percentage of unpollinated flowers on the plant increases.
(B) A plant’s fecundity decreases as the number of flowers produced by the plant decreases.
(C) A plant’s fecundity increases as the number of flowers produced by the plant increases.
(D) A plant’s fecundity is usually low if the plant relies on a small number of insect species for pollination.
(E) A plant’s fecundity is high if the plant can reproduce quickly by means of vegetative growth as well as by the production of seeds.

6 
 6. It can be inferred from the passage that which of the following plant species would be LEAST likely to experience a decrease in fecundity as a result of the spraying of a pesticide not directly toxic to plants?

(A) A flowering tree pollinated by only a few insect species
(B) A kind of insect-pollinated vine producing few flowers
(C) A wind-pollinated flowering tree that is short-lived
(D) A flowering shrub pollinated by a large number of insect species
(E) A type of wildflower typically pollinated by larger insects

7 
 7. Which of the following assumptions most probably underlies the author’s  tentative recommendation in lines 51-54?

(A) Human activities that result in environmental disruption should be abandoned.
(B) The use of pesticides is likely to continue into the future.
(C) It is economically beneficial to preserve endangered plant species.
(D) Preventing the endangerment of a species is less costly than trying to save an already endangered one.
(E) Conservation efforts aimed at preserving a few well-chosen species are more cost-effective than are broader-based efforts to improve the environment.

arundas · Accepted Answer

Question 7:

The last statement: 
Perhaps we should give special attention to the conservation of such plant species since they lack key factors in their defenses against the environmental disruption caused by pesticide use.

Question#7 Which of the following assumptions most probably underlies the author’s tentative recommendation in lines 51-54?

(A) Human activities that result in environmental disruption should be abandoned.

-- To extreme

(B) The use of pesticides is likely to continue into the future.

-- As the author talks about handling the disruption caused by pesticide it means that pesticide would be continued to be used in future

(C) It is economically beneficial to preserve endangered plant species.

-- Out of scope: Author does not talk about economic benefits

(D) Preventing the endangerment of a species is less costly than trying to save an already endangered one.

-- Out of scope: Author does not talk about cost anywhere

(E) Conservation efforts aimed at preserving a few well-chosen species are more cost-effective than are broader-based efforts to improve the environment.

-- Out of scope: Author does not talk about cost anywhere

AndrewN · Answer

Hello,  SophieZhang . You have to be careful when answering RC or CR questions to stick to exactly what the passage says. Otherwise, multiple answers will start to look too close to call, and you will never see the task as anything more than a guessing game.

Since the question refers to the definition of  plant fecundity  provided by the passage, we need to find that definition, which is given in the middle of the second paragraph:

plant fecundity, expressed as  the percentage  of the total flowers on an individual plant that actually developed fruit and bore seeds

Looking at the answer choices, we can get rid of any that do not take such a percentage into account.

In one fell swoop, we have gotten rid of two tricky answers, both of which seem to stem from the final paragraph. Of the three remaining options, (B) and (C) latch on to the same idea and cannot really be teased apart: if one of them were correct, then so, too, ought to be the other. That leaves us with (A), and that answer does, in fact, resemble the definition given in the passage. If  unpollinated flowers  increase as a percent of the total flowers on a plant, then that plant is understood to have a decreased fecundity.

I cannot stress the point enough: stick to just what the passage says. The more you bring in associative thoughts, the less likely you will be to walk away with the correct answer, and the longer you will likely take to answer the questions (a double whammy).

I hope that helps. Thank you for thinking to ask me about the question.

- Andrew

thanhtam0102 · Answer

2. According to the author, a flowering plant species whose fecundity has declined due to pesticide spraying may not experience an overall population decline if the plant species can do which of the following?
(A) Reproduce itself by means of shoots and runners.
" on the other hand, vegetative growth and dispersal (by means of shoots or runners) are available as alternative reproductive strategies for a species, then decreases in plant fecundity"

3. The passage suggests that the lack of an observed decline in the fecundity of the creeping dogwood strengthens the researchers conclusions regarding pesticide use because the
(D) creeping dogwood is similar to the red-osier dogwood, but its insect pollinators are known to be insensitive to the pesticide used in the study
"The creeping dogwood, a species similar to the red-osier dogwood, but which is pollinated by large bees, such as bumblebees, showed no significant decline in fecundity."

4. The passage suggests that which of the following is true of the forest regions in New Brunswick sprayed with most anti-budworm pesticides other than Matacil?
(A) The fecundity of some flowering plants in those regions may have decreased to an even greater degree than in the regions where Matacil is used.
"New Brunswick various pesticides have been sprayed in the past 25 years ; Matacil, one of the anti-budworm agents that is least toxic to insect-pollinators."

5. It can be inferred that which of the following is true of plant fecundity as it is defined in the passage?
(A) A plant's fecundity decreases as the percentage of unpollinated flowers on the plant increases.
" flowering plant species dependent on insect pollination could be endangered when the population of insect-pollinators is depleted by the use of pesticides." It means that unpollinated flowers increase will lead to the decreasing in number of plant (fecundity).

(C) A plant's fecundity increases as the number of flowers produced by the plant increases. 
"It maybe true but the reproduction of many other plants depend on shoots or runners." So choice A is much clearer.

6. It can be inferred from the passage that which of the following plant species would be LEAST likely to experience a decrease in fecundity as a result of the spraying of a pesticide not directly toxic to plants?
(C) A wind-pollinated flowering tree that is short-lived
" Thus, flowering plant species dependent on insect pollination, as opposed to self-pollination or wind pollination, could be endangered when the population of insect-pollinators is depleted by the use of pesticides." It means that wind pollination may have not negative impacts by the use of pesticides.

(E) A type of wildflower typically pollinated by larger insects. 
"The creeping dogwood, a species similar to the red-osier dogwood, but which is pollinated by large bees, such as bumblebees, showed no significant decline in fecundity."

7. Which of the following assumptions most probably underlies the author's tentative recommendation in lines 51-54?
(A) Human activities that result in environmental disruption should be abandoned.
(B) The use of pesticides is likely to continue into the future.
 I think we can easily remove choice C, D and E since there is no information related to cost in the last sentence of the passage. 
Choice A uses the word "abandoned", which did not appear in the sentence, and the author only warn people to pay attention to the use of pesticides. 
"pay attention to the use of pesticides." It implies that there is no regulation to stop using pesticides, or using pesticides may continue to use. 
Choice B correct.

NandishSS · Answer

HI  GMATGuruNY ,  AndrewN  ,  GMATCoachBen  ,  BrightOutlookJenn

For the first question is it not author trying to say - "Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when one species involved in the relationship is affected by a catastrophe." - then he goes on to provide the example?

GMATGuruNY · Answer

The correct answer must be supported by EVERY PARAGRAPH.
Here, every paragraph focuses on the USE OF PESTICIDES:

Paragraph 1:
 Flowering plant species could be endangered by the use of pesticides.

Paragraph 2:
 Various pesticides have been sprayed in the past 25 years in efforts to control the spruce budworm.
These results add weight to the argument that...the pesticide used decreases plant fecundity.

Paragraph 3:
 The question of whether...the spraying of pesticides actually causes a decline in the overall population...remains unanswered.
Perhaps we should give special attention to the...environmental disruption caused by pesticide use.

Thus, the main point is expressed by C:
 The use of pesticides may be endangering certain plant species.

C

AndrewN · Answer

Hello,  NandishSS . I agree with the approach  GMATGuruNY  has outlined above. I will add that you have to be careful not to rely on quick fixes for answers to RC questions, particularly those that are broad in scope. Simply looking to the first or last lines of a passage may not prove sufficient to glean what the passage is driving at, although I will say, in this case, that the final line does place an emphasis on plant conservation in light of pesticide use, and that notion falls in line with choice (C). If you were confused about (A), notice how, after the comma, the second clause veers into questionable territory by focusing on insects and the  generally positive  effect pesticide use has on them. The last line of the opening paragraph directly contradicts such an idea, though, when it mentions the depletion of insect-pollinators  by the use of pesticides . Finally, the closing paragraph barely mentions insects, except to say that insect-pollinators have a  profound impact  on certain plant species. That is a far cry from discussing the benefits of pesticide use to insects. Choice (A) is a trap answer that lifts some of the keywords from the opening line of the passage, but it does not hold up to scrutiny at all. None of the other answers makes a compelling case as a reasonable option.

I hope that helps you out. Thank you for thinking to ask me about the question.

- Andrew

SophieZhang · Answer

Hi Andrew,

Could you explain Q5? Why D is wrong, in the last p has defined feceulity with 4 factors, small number of insect pollinator is one of them, I really don't understand

mSKR · Answer

Hi  IanStewart   EducationAisle   CrackVerbalGMAT   GMATNinja

Could you give your comments on how to avoid answer D for Q6?

The fecundity effects described here are likely to have the most profound impact on plant species with all four of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species.

The above statement make me choose options:

a dependence on a small number of insect-pollinator species= Opposite of option D
Although after finding " A wind-pollinated" in C , C wins over D.

Query on Q: 
If no C option, is there any chance D could be still an answer?
I am not able to reject D with confidence .
Please suggest.

During exam mode, these incidents are very normal. ( for some questions, it saves time but some question such as this one, it became disaster ).
 My query: 
What can we do not to miss such hints /key words/adjectives during the exam mode? How do you handle?

Thanks  IanStewart   EducationAisle   CrackVerbalGMAT   GMATNinja

EducationAisle · Answer

Yes, I think so.

However, the question asks us which of the following plant species would be LEAST likely to experience a decrease in fecundity as a result of the spraying of a pesticide not directly toxic to plants. So, C is clearly the winner because the introductory para clearly says: "Thus, flowering plant species dependent on insect pollination, as opposed to self-pollination or  wind pollination , could be endangered when the population of insect-pollinators is depleted by the use of pesticides.".

So, it is clear that in case of  wind pollination , spraying of a pesticide has  ZERO  effect on pollination.

On the other hand, if a flowering shrub pollinated by a large number of insect species, there will obviously be  some  effect of the spraying of a pesticide. The quantum of the effect would depend on the number of pollinators (insect species) that are effected by the pesticide.

heyrohit · Answer

This feels like a torture for someone who don't know the meaning of fecundity.

Had the author added just one line that fecundity is similar to fertility, the passage would have been such a breeze. But that's what these authors do. More I come to such passages, more I doubt why I am studying for this exam.

GMATGuruNY · Answer

The second paragraph defines  plant fecundity  as   the percentage of the total flowers on an individual plant that actually developed fruit and bore seeds.

Mavisdu1017 · Answer

Hi expert,
Can any expert explain Q6? I was torn by C and D. As passage says short life span is a disadvantage character, and C says tree with short-live. 
While D says a large number of pollinators, that should be an advantage character. So how to compare C to D? Thanks in advance.

GMATGuruNY · Answer

Which of the following plant species would be LEAST likely to experience a decrease in fecundity as a result of the spraying of a pesticide not directly toxic to plants?

Focus on the BIG IDEA:
 Species interdependence can become a point of weakness when one species involved in the relationship is affected by a catastrophe. Thus, flowering plant species dependent on insect pollination could be endangered when the population of insect-pollinators is depleted by the use of pesticides.

Implication:
A plant species NOT dependent on insect-pollinators would be LEAST likely to be affected by the use of pesticides.
Of the five answer choices, only C refers to a plant species not dependent on insect pollination:
 a wind-pollinated flowering tree that is short-lived

C

According to the passage, plants most at risk have  ALL FOUR of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species. 
The passage does not say that a short life span ON ITS OWN is a disadvantage.

Mavisdu1017 · Answer

GMATGuruNY  sorry expert, don’t get you well. How should I comprehend this sentence: plants most at risk have  ALL FOUR of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species.
I think at risk means a disadvantage. Mind to explain further? Thanks

GMATGuruNY · Answer

What the passage DOES NOT say:
 The fecundity effects described here are likely to have the most profound impact on plant species with  AT LEAST ONE  of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species. 
Here, the phrase in red conveys that -- for a plant to be profoundly affected by pesticide use -- it must have AT LEAST ONE of the four characteristics.
As a result, there will be a profound effect on a plant that has a short life span but that lacks the other three characteristics.

What the passage ACTUALLY says:
 The fecundity effects described here are likely to have the most profound impact on plant species with  ALL FOUR  of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species. 
Here, the phrase in blue conveys that -- for a plant to be profoundly affected by pesticide use -- it must have ALL FOUR characteristics.
As a result, there will NOT be a profound effect on a plant that has a short life span but that lacks the other three characteristics.

C: A flowering tree that is short-lived 
This option refers to a short life span but does not mention the other three characteristics.
As a result, there is no indication that the flowering tree will be profoundly affected by pesticide use.

Carcass · Answer

EXPLANATION OF THE PASSAGE

Species interdependence in nature confers many benefits on the species involved, but it can also become a point of weakness when one species involved in the relationship is affected by a catastrophe.

Ok . Many species are intertwined with each other, and they have a lot of benefits from this mutual relationship. However, we do have also several drawbacks

Thus, flowering plant species dependent on insect pollination, as opposed to self-pollination or wind pollination, could be endangered when the population of insect-pollinators is depleted by the use of pesticides.

Plants depend on pollination from other animals or insects such as bees

In the forests of New Brunswick, for example, various pesticides have been sprayed in the past 25 years in efforts to control the spruce budworm, an economically significant pest.

We used pesticides to fight X but this had negative effects

Scientists have now investigated the effects of the spraying of Matacil, one of the anti-budworm agents that is least toxic to insect-pollinators.

A new compound could be be less harmful to pollinators than it was those we used 25 years ago

They studied Matacil’s effects on insect mortality in a wide variety of wild insect species and on plant fecundity, expressed as the percentage of the total flowers on an individual plant that actually developed fruit and bore seeds.

Ok Metacil was tested in the way you read above: in a certain ration. Do not need to remember in your mind. Just the location of the ratio in the passage just in case you need it to recall

They found that the most pronounced mortality after the spraying of Matacil occurred among the smaller bees and one family of flies, insects that were all important pollinators of numerous species of plants growing beneath the tree canopy of forests.

From the use of Matacil your bees and ONE family of flies were affected

The fecundity of plants in one common indigenous species, the red-osier dogwood, was significantly reduced in the sprayed areas as compared to that of plants in control plots where Matacil was not sprayed.

This specific plant if handled with the matacil had influenced the production if used

This species is highly dependent on the insect-pollinators most vulnerable to Matacil.

Red-osier heavenly depends on the pollinators that are affected a lot by Matacil

The creeping dogwood, a species similar to the red-osier dogwood, but which is pollinated by large bees, such as bumblebees, showed no significant decline in fecundity.

Another plant similar to the red osier- in the same scenario was not affected or at least in a minimum way nor the pollinators LARGE bees

Since large bees are not affected by the spraying of Matacil, these results add weight to the argument that spraying where the pollinators are sensitive to the pesticide used decreases plant fecundity.

The sentence above tell us that probably Matacil is dangerous for YOUNG bees but not Older or LARGE bees

The question of whether the decrease in plant fecundity caused by the spraying of pesticides actually causes a decline in the overall population of flowering plant species still remains unanswered.

regardless the first observations we do not have conclusive results to be certain

Plant species dependent solely on seeds for survival or dispersal are obviously more vulnerable to any decrease in plant fecundity that occurs, whatever its cause.

also plant that depends from the fecundity of other plant could be also affected. Not sure thought this is the real meaning of this portion. Kinda blurry

If, on the other hand, vegetative growth and dispersal (by means of shoots or runners) are available as alternative reproductive strategies for a species, then decreases in plant fecundity may be of little consequence.

In the scenario above, having an alternative, the fecundity could be the same

The fecundity effects described here are likely to have the most profound impact on plant species with all four of the following characteristics: a short life span, a narrow geographic range, an incapacity for vegetative propagation, and a dependence on a small number of insect-pollinator species.

The fecundity could be impacted for the reasons above

Perhaps we should give special attention to the conservation of such plant species since they lack key factors in their defenses against the environmental disruption caused by pesticide use.

Conclusion of the argument

Carcass · Answer

EXPLANATION #1

1. Which of the following best summarizes the main point of the passage?

(A) Species interdependence is a point of weakness for some plants, but is generally beneficial to insects involved in pollination.

Not really

(B) Efforts to control the spruce budworm have had deleterious effects on the red-osier dogwood.

Just a fact and also is not related each other

(C) The used of pesticides may be endangering certain plant species dependent on insects for pollination.

Clearly the right answer. It is correct in 30 seconds once reading

(D) The spraying of pesticides can reduce the fecundity of a plant species, but probably does not affect its overall population stability.

Just a fact in details

(E) Plant species lacking key factors in their defenses against human environmental disruption will probably become extinct.

Totally out of scope

Carcass · Answer

EXPLANATION #2

2. According to the author, a flowering plant species whose fecundity has declined due to pesticide spraying may not experience an overall population decline if the plant species can do which of the following?

(A) Reproduce itself by means of shoots and runners.

Yes true. See the portion of the passage where alternative ways of pollination can stabilize the fecundity of the plants

(B) Survive to the end of the growing season.

Out of scope

(C) Survive in harsh climates.

never mentioned the climate

(D) Respond to the fecundity decline by producing more flowers.

Never mentioned this detail about more flowers

(E) Attract large insects as pollinators.

Out of scope never mentioned

Carcass · Answer

EXPLANATION #3

3. The passage suggests that the lack of an observed decline in the fecundity of the creeping dogwood strengthens the researchers conclusions regarding pesticide use because the

(A) creeping dogwood is a species that does not resemble other forest plants
(B) creeping dogwood is a species pollinated by a broader range of insect species than are most dogwood species
(C) creeping dogwood grows primarily in regions that were not sprayed with pesticide, and so served as a control for the experiment
(D) creeping dogwood is similar to the red-osier dogwood, but its insect pollinators are known to be insensitive to the pesticide used in the study
(E) geographical range of the creeping dogwood is similar to that of the red-osier dogwood, but the latter species relies less on seeds for reproduction

if you scan the option vertical the ONLY mentioned in the passage is that  creeping dogwood is similar to the red-osier

D in 10 seconds is the right choice

Species interdependence in nature confers many benefits on the species

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GMAT Reading Comprehension (RC) Questions

Species interdependence in nature confers many benefits on the species

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