In some species of cricket, the number of chirps per minute used by th

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended core meaning of this sentence is that the number of chirps per minute used by the male cricket to attract females rises and falls in accordance with the surrounding temperature, and this number can in fact serve as an approximate thermometer.

Concepts tested here: Subject-Verb Agreement + Pronouns + Meaning + Modifiers + Verb Forms

• For referring to the purpose/intent of an action, the infinitive verb form ("to + base form of verb" – “to + attract” in this case) is preferred over the present participle ("verb+ing" - "attracting" in this case).
• "who/whose/whom/which/where", when preceded by a comma, refers to the noun just before the comma.

A: This answer choice incorrectly refers to the singular noun "number" with the plural verbs "rise" and "fall". Further, Option A incorrectly refers to the singular noun "number" with the plural pronoun "they". Additionally, Option A uses the present participle ("verb+ing" - "attracting" in this case) to refer to the purpose of the action "used"; remember, for referring to the purpose/intent of an action, the infinitive verb form ("to + base form of verb") is preferred over the present participle ("verb+ing" - "attracting" in this case).

B: This answer choice incorrectly refers to "the surrounding temperature" with "which can in fact serve", illogically implying that the surrounding temperature can serve as an approximate thermometer; the intended meaning is that the number of chirps per minute used by the male cricket to attract females can serve as an approximate thermometer; remember, "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma. Further, Option B uses the present participle ("verb+ing" - "attracting" in this case) to refer to the purpose of the action "used"; remember, for referring to the purpose/intent of an action, the infinitive verb form ("to + base form of verb") is preferred over the present participle ("verb+ing" - "attracting" in this case).

C: This answer choice incorrectly refers to the singular noun "number" with the plural verbs "rise" and "fall". Further, Option C alters the meaning of the phrase through the construction "in fact possibly serving"; the construction of this phrase incorrectly implies that the number of chirps practically serves as an approximate thermometer; the intended meaning is that the number of chirps can serve as an approximate thermometer. Further, Option C uses the present participle ("verb+ing" - "attracting" in this case) to refer to the purpose of the action "used"; remember, for referring to the purpose/intent of an action, the infinitive verb form ("to + base form of verb") is preferred over the present participle ("verb+ing" - "attracting" in this case).

D: Correct. This answer choice correctly refers to the singular noun "number" with the singular verbs "rises" and "falls" and the singular pronoun "it". Further, Option C uses the clause "and it can in fact serve", conveying the intended meaning - that the number of chirps can serve as an approximate thermometer. Additionally, Option D uses the infinitive verb form ("to + base form of verb" - "to + attract" in this sentence) to refer to the purpose of the action "used".

E: Trap. This answer choice alters the meaning of the phrase through the construction "in fact possibly serving"; the construction of this phrase incorrectly implies that the number of chirps practically serves as an approximate thermometer; the intended meaning is that the number of chirps can serve as an approximate thermometer.

Hence, D is the best answer choice.

To understand the concept of "Infinitive" versus "Present Participle" on GMAT, you may want to watch the following video (~1 minute):



To understand the concept of "Which", "Who", "Whose", and "Where" on GMAT, you may want to watch the following video (~1 minute):



All the best!
Experts' Global Team

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an approximate thermometer.

A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting females rises and falls in accordance with the surrounding temperature, which can in fact serve
C. in attracting females rise and fall in accordance with the surrounding temperature, in fact possibly serving.
D. to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve.
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly serving.

Here's how to answer this question in <30 seconds.

Step 1) Read "the number of chirps used by the male TO DO SOMETHING"

Recognize that the structure is "used by the male TO DO SOMETHING" - so you skim down the first few words of each answer choice and notice only (D) and (E) have "to attract" as the first two words.

Step 2) Now that you've narrowed it down to (D) and (E), don't bother reading from the top of the sentence stem anymore.

Just continue reading through answer choice (D). So we have:
"the number of chirps used by the male TO ATTRACT X rises and falls in accordance with the surrounding temperature, and it can in fact serve..."

"it can in fact serve" - what is "it" referring to? It's referring to "number of chirps."

"And the number of chirps can in fact serve as an approximate thermometer" - that's what choice (D) suggests.

What does chocie (E) suggest?

(E): "the number of chirps used by the male TO ATTRACT females [does x], in fact possibly serving as an approximate thermometer."

Wait a minute, we have "serving as thermometer" at the end but in the beginning we have: "does x" - specifically "rises and falls"

"Rises and falls" is NOT consistent with "serving as a thermometer" - see (E) looks no good.

Let's look back at (D).
(D): "number of chirps rises and falls...and [the number of chirps] can serve as a thermometer"

Ah - that's more like it. The number of chirps rises and falls..and can serve as a thermometer. The verb tenses are more consistent here than they are in (E).

Step 3) Compare (D) and (E) and recognize that only (E) uses consistent verb tenses on both sides of the sentence. Pick (D) and move on.

If something is a fact, we can't say it is possible. Because it is a fact.

Hi Folks,

D to attract females rises and falls in accordance with the surrounding temperature, and it can in fact serve

"It" refers to "The no of chirps per minute"
Can someone please explain how could "The no of chirps per minute" server as an thermometer... ?? quiet strange

The idea in this sentence is that one could, it one wanted, measure the temperature by counting the number of chirps per minute produced by some male crickets. Since the frequency of chirps rises and falls with the temperature, someone could count the chirps and determine the approximate temperature. Of course, this person would need some data on the number of chirps per minute at different temperatures to get a sense of the scale.

So, PrakharGMAT, that's how the number could serve as a thermometer.

Ergenekon, notice that we are definitely describing a possibility more than an established practice. It seems unlikely that anyone actually measures the temperature in this way! In any case, there's no rule that says that something that has been established as a fact can't be described as possible. In fact, we do this all the time. Someone will accomplish something, and we'll say that we now know that accomplishment is possible. The problem with E actually goes a bit in the other direction. If we follow the main clause with "possibly serving," we're saying that this number may in fact be serving as a thermometer. In other words, E implies that the crickets (or someone else unnamed) may routinely use this number to measure the temperature, and that's not really what the author is getting at.

Hi,


Very sorry to open this thread. Here is why I choose D over E

'D' Has two independent clauses joined by 'and, and pronoun 'it' refers to noun number of thermometers, which is all fine and clear.
'E' has (in fact possibly) serving which acts as an -ing modifier preceded by comma which modifies the entire clause and refers to the subject. However, here "The number of chirps....................with the surrounding temperature' is enclosed within two commas which makes it a parenthetical information and serving illogically refers to "species of cricket".

Can anyone confirm/explain if my reasoning for ruling out 'E' correct?

Thanks in advance.

I'm afraid that doesn't work. If the end modifier ("serving") were a noun modifier, it would need to be much closer to the noun in question. An "-ing" word preceded by a comma typically introduces an adverbial modifier, and that's what we have here. There's nothing wrong with that grammatically, and that's why we have to go with the meaning issue I described.

Responding to a pm:


The number of chirps is what could act as a thermometer. We would of course need a conversion scale. Depending on the "number of chirps" and its corresponding temperature reading on the scale, we could guess the temperature.
Hence, "it" refers to "number of chirps"

As for (E), it implies that the number of chirps possibly serves as a thermometer. It doesn't. Nobody actually uses the number of chirps as a thermometer. (D) implies that it could serve i.e. it has the ability to serve as a thermometer (even though we wouldn't really use it normally).

In some species of cricket, the number of chirps (Singular Subject) per minute used by the male for attracting (Wrong Idiom: use 'TO' to express intend or objective) females rise and fall (Plural Verb: S-V disagreement) in accordance with the surrounding temperature, and they (Unclear Antecedent: the number of chirps ? should be IT) can in fact serve as an approximate thermometer.

A. for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve.
B. for attracting (Wrong Idiom) females rises and falls in accordance with the surrounding temperature, which (Refers to temperature - changes the meaning of original sentence) can in fact serve
C. in attracting (Wrong Idiom) females rise and fall (Plural Verb: S-V disagreement) in accordance with the surrounding temperature, in fact possibly serving (Verb + ing modifier: Can modify preceding clause, preceding noun, or even the subject of the preceding clause. Qualifies 'the number of chirps'? or 'surrounding temperature'? or entire clause ?)
D. to attract (Correct Idiom) females rises and falls (Singular Verb) in accordance with the surrounding temperature, and it (Keeps ||ism intact with 'the number of chirps' - singular subject) can in fact serve. - Best choice
E. to attract females rises and falls in accordance with the surrounding temperature, in fact possibly serving (Verb + ing modifier: Can modify preceding clause, preceding noun, or even the subject of the preceding clause. Qualifies 'the number of chirps'? or 'surrounding temperature'? or entire clause ?)

Please explain what is wrong in option E and whats correct in option D

From a PM:


"Can" isn't the same thing as "possibly." "Can" indicates potential or ability -- so in (D), the number of chirps has the ability to serve as a thermometer. And it's reasonable enough to say that it does, "in fact", have that ability. "Possibly" simply indicates that we don't really know whether something is actually occurring; it says nothing about ability or potential.

So (E) is saying something slightly different from (D): the number of chirps is "in fact possibly serving" as an approximate thermometer. And that's muddier, as described in both my explanation and in sayantanc2k's above.

Isn't ''used for'' wrong in A,B,C? I found that this is wrong in a file, perhaps compiled by carcass , containing 100 hard SC ques from OG and Manhattan.

Hello rma26,

I will be glad to help you out with this one.

As such the phrase used for is not incorrect.

However, in this official sentence, we need the phrase to attract to show why male crickets use their chirps in a certain manner. Hence use of for attracting is not correct.

Hope this helps.
Thanks.
Shraddha

shouldnt it be serves instead of serve in option D

Nope! Sure, "it serves" would be correct, but there's a helping word ("can", "must", "may", "should", etc.) in the sentence, so "it can serve" would be correct.

Hey GMATNinja,

I was stuck with options D&E. But chose D since E was nonsensical.
But I found it really hard to eliminate D because "it" was not referring back to a noun but to a phrase " the number of chirps per minute ".
Is this usage grammatically correct ??

Thanks in advance
Hareesh

The grammar in an OA is always correct! And this usage is quite common. Consider a silly example: "The number of dogs my toddler has frightened with her aggressive displays of affection is high, and if it continues to increase, we will likely receive a reprimand from the neighborhood association." Here "it" refers to "the number of dogs" or "the number." If that number "continues to increase" there will be consequences. Perfectly logical.

I hope that helps!