The intricate structure of the compound insect eye, having hundreds of

Hello Everyone!

Let's take a close look at this question, one problem at a time, to come up with the right answer quickly! Before we dive in, here is the original question with the major differences between each option highlighted in orange:

The intricate structure of the compound insect eye, having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it evolved independently of the vertebrate eye.

(A) having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it
(B) having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they
(C) with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they
(D) with its hundreds of miniature eyes called ommatidia, help explain scientists' assuming that it
(E) with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it

Right away, 3 major differences jump out between each option:

1. having hundreds / with its hundreds
2. help / helps
3. it / they

#2 and #3 on the list are both easy concepts to deal with, so let's start there before getting to #1 on the list, which is a little more complicated.

#2 on our list deals with subject/verb agreement. We know that the subject is the singular word "structure." Let's rule out any options that use the plural verb "help," which doesn't agree in number with our singular subject!

(A) having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it
(B) having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they
(C) with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they
(D) with its hundreds of miniature eyes called ommatidia, help explain scientists' assuming that it
(E) with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it

There you go - right away, we can eliminate options A & D because they don't follow proper subject/verb agreement!

Now, let's tackle #3 on our list: it/they. This is an issue of pronoun/antecedent agreement! The pronouns are referring back again to our subject: structure. Let's rule out any options that use the plural pronoun "they" because it doesn't agree in number with our singular antecedent:

(B) having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they
(C) with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they
(E) with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it

This leaves us with only one option left - option E, which is the correct answer! It uses proper subject/verb agreement and pronoun/antecedent agreement throughout!

(If you're wondering why we skipped over #1 on our list, it's because both constructions are actually okay to use. Instead of wasting time fretting over something that looks confusing, start with the easy differences first, such as subject/verb agreement or pronoun/antecedent agreement. Most of the time, those will rule out enough options for you to choose the correct overall answer. If not, then you can take more time to deal with the more complicated stuff.)


Don't study for the GMAT. Train for it.

Dear Friends,

Here is a detailed explanation to this question-

Concepts tested here: Subject-Verb Agreement + Pronouns + Awkwardness/Redundancy

A: This answer choice incorrectly refers to the singular noun "eye" with the plural verb phrase "help explain".

B: This answer choice incorrectly refers to the singular noun "eye" with the plural pronoun "they". Additionally, Option B uses the needlessly wordy phrase "that are called ommatidia", leading to awkwardness and redundancy.

C: This answer choice incorrectly refers to the singular noun "eye" with the plural pronoun "they". Additionally, Option C uses the needlessly wordy phrase "that are called ommatidia" and the passive voice construction "scientists' assuming", leading to awkwardness and redundancy.

D: This answer choice incorrectly refers to the singular noun "eye" with the plural verb phrase "help explain". Additionally, Option D uses the passive voice construction "scientists' assuming", rendering it awkward and needlessly indirect.

E: Correct. This answer choice correctly refers to the singular noun "eye" with the singular verb phrase "helps explain" and the singular pronoun "it". Additionally, Option E is free of any awkwardness or redundancy.

Hence, E is the best answer choice.

All the best!
Experts' Global Team

A having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it (SV error)
B having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they (Pronoun error)
C with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they(Pronoun error)
D with its hundreds of miniature eyes called ommatidia, help explain scientists' assuming that it (SV error)
E with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it (Correct Answer)

Hi......
i have a doubt regarding antecedents for pronoun,.....
In OG13,#81,
"Fossils of the arm of a sloth found in Puerto Rico in 1991, and dated at 34 million years old, made it the earliest known mammal of the greater antiles islands. "

OG explanation for this sentence being wrong- "sloth is the object of a preposition and not the subject of the sentence, there is no reasonable antecedent for the pronoun it ".

but in OG13,#7,
"The intricate structure of the compound insect eye, with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it evolved independently of the vertebrae eye."
above is the correct sentence as per OG....
here, compound insect eye is the object of the preposition... so in the modifier "with its...." , its cannot refer to compound insect eye.... but OG says its refers to the compound insect eye..........
contradicting explanations in two different sentences... help pls...

First split : The intricate structure......... HELP/HELPS explain........

The intricate structure ( singular )..... must be paired with Helps ( singular verb )

A,D disappears, Left with B, C, E

2nd Split : Scientists assumed that....... THEY / IT........

The pronoun refers back to the EYE ( Singular )........ So the Pronoun should be IT ( SINGULAR ) and not THEY.

Thus B n C get back to their cocoon.

Leading to E, my take

Hi stotite,

The difference here lies in the meaning. You're basically asking why the descriptive phrase seems to be describing the second noun or object of the sentence--but in one case, it's used correctly and in the other case it's used incorrectly.

Here are the two examples:

(1) "Fossils of the..sloth, made it the earliest known mammal..."

(2) "The intricate structure of the compound insect eye..."

The sentences seemingly have the same structure. Why, then is (1) no good and (2) is good?

The difference is in the meaning.

In (1) when we say "fossils of the sloth" - we are bringing up two very different things. One is the actual sloth. The other is a fossil - something that was DERIVED from the original sloth.

In (2) when we say "intricate structure of the eye" - INTRICATE STRUCTURE is merely a DESCRIPTION of the eye. We're still talking about the eye, but more specifically we are referencing the intricate structure of the eye. You're still talking about the eye in general in both cases.

This contrasts with the situation in (1) where you are potentially referencing two different things - one is the fossil of the sloth and the other is the sloth itself. So when you use the word IT - the reader won't know which one you are referring to.

But in (2) when you use IT - you are clearly referencing the "intricate structure of the eye" as a whole mainly because the phrase is not composed of 2 different elements. Rather, the intricate structure is a characteristic of the eye. Whereas the "fossil" is not really a characteristic of the "sloth."

For more information on these subtleties and other SC frameworks, please reference the SC Pill Core Framework #3.

Hii supri.
Though I am not an expert, I will still try my best.
(A)having hundreds of miniature eyes called ommatidia,help explain why scientists have assumed that it Note that "haiving hundreds of miniature eyes called ommatidia" is modifying the entire preceding clause "The intricate structure of the compound insect eye". Logically the "structure" is not having hundreds of eyes but "compound insect eye" has. Also, on removing this modifier, the sentence becomes The intricate structure of the compound insect eye HELP explain why scientists have assumed that it evolved independently of the vertebrate eye.
The HELP does'nt agree with the subject of the previous clause "the intricate structure" and hence incorrect. It should be HELPS.
(B)having hundreds of miniature eyes that are called ommatidia,helps explain why scientists have assumed that they "They" hasn't got any logical referent here. Use of "that are called" seems pretty wordier. It can be easily written as "...called".
(C)with its hundreds of miniature eyes that are called ommatidia,helps explain scientists` assuming that they
"scientists' assuming" is a noun and cannot come after "explain" in this context. Since you are also a noun, try putting your name after explain. ex-"...helps explain supri". Its illogical. "that are called" is still wordier. No logical referent for "they".
(D)with its hundreds of miniature eyes called ommatidia,help explain scientists` assuming that it
Same as C.
(E)with its hundreds of miniature eyes called ommatidia,helps explain why scientists have assumed that it CORRECT..

+1E.
Hope that helps.
-s

I figured out the errors with each answer choice much similar to the ways listed above. I was looking at one point in OG answer explanation that "using 'assuming' with possesive 'scientists'' form" is incorrect. Say, if i change answer (C) as below, will it be correct.

(C) with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' ASSUMPTION that IT

Hi mamthak

Even you change assuming to assumption, the sentence is still wrong because:

- Structure: "assumption that + clause" is not as good as "assume that + clause"
(1) Scientists have the assumption that whale evolved from elephant
(2) Scientists assume that whale evolved from elephant
Which one is better. Definitely, GMAT likes the latter, it's more concise and has clear meaning.
Remember the order V-A-N (verb-adjective-noun). If you can use verb, use verb, do not use noun form.

- Idiom: assumption that ==> incorrect. Correct idiom is "assumption of/about"

Hope it' clear.

Could somebody please clarify me how "with" is different from "having" here.

How is it that "having" is modifying "structure", while "with" is modifying "compound insect eye". Kindly help me understand the usage of with here.

Thanks a lot GmatClub.

Could you help me on how "with" modifies the "eye" and not the "structure"?

WITH ...will modify eye.....according to context of the sentence)

it cannot modify intricate structure as that will be illogical....to say intricate structure have hundreds of miniature eyes.


The intricate structure of the compound insect eye,withits hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it evolved independently of the vertebrate eye


HOPE IT IS CLEAR.

I thought I understood the usage of "with" until I saw this official sentence.

I believe that if I am changing the rules of using a concept every time so as to match the correct answer, then I am sure that I didn't understand the concept well. I believe that is exactly what is happening in this case in understanding the usage of "with" on the GMAT.

In our previous conversation, we thought "with" modifies the preceding noun or the clause. But, it looks like we're missing something here. Below is an official sentence from the GMAT Prep.

Sentence: (This is the correct option in the question. But, the stress here is to understand how is it correct?)

Visitors to the park have often looked up into the leafy canopy and saw monkeys sleeping on the branches, with arms and legs hanging like socks on a clothesline.

The official explanation says "with" is modifying "monkeys" correctly and it is not modifying "branches".

I don't understand why is it so? According to our understanding, "with" should modify the preceding noun "branches".

I understand that branches cannot have arms and legs and hence it modifies monkeys. I think this explanation doesn't solve the problem. Because, there has to be a better explanation to this usage. Else, we're saying that "with" is always correct on the GMAT as it can be associated to modify anything as desired by the context of the sentence.

I believe we need to understand this better.

I request the experts on this forum to please help us on this.

Thanks a lot!!

Firstly, both the verbs "have often looked up" and "saw" are associated to "Visitors". I'd expect the second verb also to be in a a form that aligns with "have" => verb should be "have seen" .

Secondly to generalise this concept of usage of "with XXX" --> it falls into the category of prepositional phrases , which are very versatile , and everything that's said about "with" being a versatile modifier applies to all prepositional phrases

In this specific Question - i think "with arms and legs hanging like ..... " modifies the noun phrase "monkeys sleeping on the branches" . it simply cannot modify just branches or monkeys. "with ....." here describes HOW monkeys are sleeping on the branches , modifying the action denoted by the -ING modifer sleeping.

The intricate structure of the compound insect eye, having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it evolved independently of the vertebrate eye.

A having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it
B having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they
C with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they
D with its hundreds of miniature eyes called ommatidia, help explain scientists' assuming that it
E with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it


This sentence addresses why scientists have decided that the vertebrate eye arid the insect eye evolved independently of each other. The insect eye is much more intricate, with hundreds of miniature eyes. The sentence needs to be clear as to what has hundreds of miniature eyes. The structure or the insect eye? Furthermore, the singular subject intricate structure requires the singular verb helps.

A. having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it
having..modified subject of the preceding clause "The intricate structure" and meaning looks like The intricate
structure has miniature eyes(insect eye has miniature eyes).so this option is out

B. having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they
Option B is out for the same reason as given in Option A.

C. with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they
The intricate structure ...helps(correct). they(plural) is refer to back to The intricate structure(singular)..so
Incorrect

D. with its hundreds of miniature eyes called ommatidia, help explain scientists' assuming that it
The intricate structure ...help(incorrect)

E. with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it
The intricate structure ...helps(correct).It refers to The intricate structure...Correct.

The intricate structure of the compound insect eye, having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it evolved independently of the vertebrate eye.

A having hundreds of miniature eyes called ommatidia, help explain why scientists have assumed that it
B having hundreds of miniature eyes that are called ommatidia, helps explain why scientists have assumed that they
C with its hundreds of miniature eyes that are called ommatidia, helps explain scientists' assuming that they
D with its hundreds of miniature eyes called ommatidia, help explain scientists' assuming that it
E with its hundreds of miniature eyes called ommatidia, helps explain why scientists have assumed that it

Sir,

This is OG13 Q7 SC. I have seen your Video on You tube, but still I have a doubt.

As per my understanding comma+with modifies the action in the preceding clause.

This is not a clause "The intricate structure of the compound insect eye". Since it doesnt have SV pair (verb missing). How come comma+with modify anything before it?
If there would have been no comma then the case be different. I think w/o comma with modifies the closest noun. Please help me where do I have Knowledge Gap.

OA : E

Dear honchos,
I'm happy to respond, my friend.

I don't know where you have heard that rule about "comma + with," but that's too rigid. The preposition "with" is very common, and it could come after a comma for any one of a number of reasons. A prepositional phrase beginning with the word "with" can be a adjectival phrase, that is, a noun modifier, or it can be an adverbial phrase, that is, a verb or clause modifier. If the "with" prepositional phrase acts as a clause modifier, then, yes, it is likely to come after a comma. Here, the "with" phrase is a noun modifier, modifying the noun "eye." It is set off by commas because it is a non-vital modifier. See:
https://magoosh.com/gmat/2012/that-vs-which-on-the-gmat/
https://magoosh.com/gmat/2012/gmat-gramm ... modifiers/
Does all this make sense, my friend?
Mike