According to some botanists, invasive plants are the second

It has to be a A since all the options are marked A!
Ok, now for the reasoning
B, D and E are not parallel
C has the ambigous 'their'

Meaning
Some botanists believe invasive plants are second most serious threat to native species of plants and animals and also to the biologically diverse eco-system.
Habitat loss is the topmost threat( according to the botanists who believe invasive plants are second most serious threat)

Error Analysis
According to some botanists
invasive plants are the second most serious threat" S- Invasive plants verb- "are.."
-after habitat loss,--prepositional phrase,
to "native species....." and to"maintain biologically....".........To X and To Y. Parallel

No Error

POE
A. threat, after habitat loss, to native species of plants and animals and to the
maintenance of biologically diverse ecosystems- Correct Choice
B. threat, after habitat loss, to native species of plants and animals and for
maintaining biologically diverse ecosystems- To"X" and For"Y" not parallel
C. threat, after losing their habitat, to native species of plants and animals and
also to maintenance of biologically diverse ecosystems-To "X" and "Also to Y" not parallel
D. threat to native species of plants and animals and for maintaining biologically
diverse ecosystems, after habitat loss- Same error as B
E. threat to native species of plants and animals as well as to maintaining
biologically diverse ecosystems, after losing their habitat- To "X" and As well as"Y" Not parallel.

The phrase - after habitat loss- contained inside a couple of commas seems to be a non-essential modifier, which seems to be wrong. If that phrase is removed, the fact that they are the second most serious threat has no meaning. The OA seems dubious as per structural norms.

B and D: the second most serious threat...FOR maintaining biologically diverse ecosystems
Here, threat FOR is unidiomatic.
The correct idiom is X is a threat TO Y.
Eliminate B and D.

C: invasive species are the second most serious threat, after losing their habitat
Here, "their" seems to refer to "invasive species", implying that INVASIVE SPECIES are losing their habitat.
The intended meaning is that NATIVE SPECIES lose their habitat.
Eliminate C.

E: maintaining biologically diverse ecosystems, after losing their habitat
Here, "their" seems to refer "diverse ecosystems", implying that "DIVERSE ECOSYSTEMS" are losing their habitat.
The intended meaning is that NATIVE SPECIES lose their habitat.
Eliminate E.
The correct answer is A.

Hi Experts / GMATNinja / chetan2u / sayantanc2k / anairamitch1804,

Can you please tell the function of the prep. phrase "after habitat loss" in this question? Is is acting as a verb modifier or the noun modifier? Thanks!

Hello sdlife,

I will be glad to help you with this one.


Prepositional phrases modify either a noun or an action in a sentence.

In this official sentence, the prepositional phrase after habitat loss modifies the action are. It intends to say that after habitat loss, invasive plants are the next biggest threat.


Hope this helps.
Thanks.
Shraddha

generis - Could you help me on this. Stuck between A and B.

Is threat to native species and for maintaining" not parallel?

Arvind42 , you asked about parallelism.
Before we consider parallelism, we should eliminate (B) because it is not idiomatic.
The correct idiom in this context is X is a threat TO something, not X is a threat FOR something.

• idiom: threat TO not threat for

Two examples of questions that test "threat" are below the spoiler.

(B) is incorrect because threat for is not idiomatic.

• parallelism
I am not sure I understand what you are asking. I think your question might be, "Irrespective of idiom, are the noun phrase native species of plants and animals and the gerund phrase maintaining biologically diverse ecosystems parallel?"

Answer: No.

It's a good question. I see a lot of confusion about gerunds, nouns, and parallelism.
Rather than just say "No, option B is not parallel because XYZ," instead I'll use some examples so that perhaps a little bit of understandable confusion gets cleared up.

Rather than analyze (B) separately, we can compare (A) and (B).
Option A uses two noun phrases:
native species of plants and animals and
the maintenance of biologically diverse ecosystems

Option B, by contrast, uses a noun phrase (native species . . . ) and a gerund phrase (maintaining biologically diverse ecosystems).
-- If a dedicated noun exists, GMAC prefers that noun to an ___ING noun (a gerund, a verbING noun).
-- The dedicated noun is maintenance (in option A). The ___ING noun is maintaining (in B).

On the GMAT, for example, the voters' approval is better than the voters' approving.

In OG 2020 SC # 835, the official explanation mentions the preference. Spoiler alert: 1 answer of 5 revealed.


In SC #842 of the same book, a noun and a gerund are deemed "not parallel" in three answers. Spoiler alert: those three are revealed.


The OE for SC # 895, option (D) explains that a gerund and noun are not parallel. Spoiler alert: 1 answer of 5 revealed.


Finally, see OG VR 2020 #304. In that question, 2 of 5 options were not parallel because a list of four items included three noun phrases and an __ING noun. (The OE writer calls it a participle.) Spoiler alert - 2 answers revealed.


I tracked down these examples because there are occasions in which a complex gerund can be parallel with an action noun, as is the case in

True, species is not an action noun. I am seeing quite a bit of confusion about gerunds and parallelism, though.
I think the best way to understand how SC works is to study official examples. So I found some.

No. Answer B is not parallel.

I hope that helps.

P.S. Arvind42 - At times the only kind of noun that exists for that word is an ING noun. Words such as running, writing, or painting (i.e. a picture that you hang on a wall) ARE the only nouns. In those cases, parallelism is not an issue. Beneath the spoiler is a question in which one noun ending in _ING is parallel to two other nouns that do not end in _ING because the _ING noun does not have any other form. Spoiler alert - clicking on the link gives the answer to a question.

BrightOutlookJenn GMATNinja DmitryFarber VeritasKarishma About (E), there is a lack of parallelism, right? I mean, "...threat to native species of plants and animals as well as to maintaining biologically diverse ecosystems..." tks!

Yes, you should use noun form "maintenance" since "native species" is a noun.

Hi VeritasKarishma! What is the issue in (E) regarding the modifier "after losing their habitat"? Tks!

'Habitat loss' is the first threat and 'invasive plants' the second.

So the sentence should read "...invasive plants are the second most serious threat, after habitat loss,..." to show that the first one is habitat loss. This relation is lost if "after habitat loss" comes later.
Also, it needs to be in noun form "habitat loss" to maintain parallelism.

Question appeared in GMAT Prep

_______________________
Added the tag. Thank you!

According to some botanists, invasive plants are the second most serious threat, after habitat loss, to native species of plants and animals and to the maintenance of biologically diverse ecosystems.

Test Points: Parallelism

A. threat, after habitat loss, to native species of plants and animals and to the maintenance of biologically diverse ecosystems
B. threat, after habitat loss, to native species of plants and animals and for maintaining biologically diverse ecosystems ("to native species of...” is a preposition phrase, but "for maintaining...“ is a verb phrase. Hence, the overall stucture does not comply with parallelism)
C. threat, after losing their habitat, to native species of plants and animals and also to maintenance of biologically diverse ecosystems (”after losing...“ distorts the original meaning)
D. threat to native species of plants and animals and for maintaining biologically diverse ecosystems, after habitat loss ("to native species of...” is a preposition phrase, but "for maintaining...“ is a verb phrase. Hence, the overall stucture does not comply with parallelism.)
E. threat to native species of plants and animals as well as to maintaining biologically diverse ecosystems, after losing their habitat. (same logic as B)

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 meaning of this sentence is that invasive plants are the second most serious threat to native species of plants and animals and are the second most serious threat to the maintenance of biologically diverse ecosystems.

Concepts tested here: Meaning + Comparisons

• Comparisons can only be made between similar things.

A: Correct. This answer choice uses the phrase "to the maintenance of biologically diverse ecosystems", conveying the intended meaning - that invasive plants are the second most serious threat to native species of plants and animals and are also the second most serious threat to the maintenance of biologically diverse ecosystems. Further, Option A correctly compares the noun phrase "invasive" plants with the noun phrase "habitat loss". Additionally, Option A is free of any awkwardness or redundancy.

B: This answer choice alters the meaning of the sentence through the phrase "for maintaining biologically diverse ecosystems"; the construction of this phrase illogically implies that invasive plants are the second most serious threat to native species of plants and animals because they maintain biologically diverse ecosystems; the intended meaning is that invasive plants are the second most serious threat to native species of plants and animals and are also the second most serious threat to the maintenance of biologically diverse ecosystems.

C: This answer choice incorrectly compares the noun phrase "invasive plants" to the verb phrase "losing their habitat"; remember, comparisons can only be made between similar things. Further, Option C uses the needlessly wordy phrase "and also", leading to awkwardness and redundancy.

D: This answer choice alters the meaning of the sentence through the phrase "for maintaining biologically diverse ecosystems"; the construction of this phrase illogically implies that invasive plants are the second most serious threat to native species of plants and animals because they maintain biologically diverse ecosystems; the intended meaning is that invasive plants are the second most serious threat to native species of plants and animals and are also the second most serious threat to the maintenance of biologically diverse ecosystems.

E: This answer choice incorrectly compares the noun phrase "invasive plants" to the verb phrase "losing their habitat"; remember, comparisons can only be made between similar things. Further, Option E uses the needlessly wordy phrase "as well as", leading to awkwardness and redundancy.

Hence, A is the best answer choice.

All the best!
Experts' Global Team