Having evolved to survive in the pitch black darkness and crushing pre

Hi rachnag,

No, they are not. I have highlighted the difference between the two below.
(A) the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enable easy locomotion
(B) the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enables easy locomotion

(B) is the correct choice here as "inverted swimming behaviour" is a noun phrase and thus takes "singular verb enables". (Pronoun that before enables refers to the noun phrase inverted swimming behaviour).

(C)/(D)/(E) can be eliminated for the lack of subject for the opening "participle phrase (Having evolved to survive in the pitch black darkness and crushing pressure found at the bottom of the ocean)".

Hope it helps.

(A) the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enable easy locomotion..behavior singular that enable wrong

(B) the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enables easy locomotion..correct

(C) developing a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior were developed by the various species of anglerfish to enable easy locomotion--modifier error

(D) developing a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior enabled easy locomotion for the various species of anglerfish--modifier error

(E) an easy locomotion enabling relationship with bioluminescent bacteria and unusual inverted swimming behaviors have been developed by the various species of anglerfish--modifier error

Having evolved to survive in the pitch black darkness and crushing pressure found at the bottom of the ocean, the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enable easy locomotion in their harsh environment.

(A) the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enable easy locomotion

(B) the various species of anglerfish have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enables easy locomotion

C, D, E wrong due to subject coma rule. A vs B - Sentence says with A&B ---> 2 things therefore pural--> enable ans is A

Expert's Global Official Explanation:

Modifiers + Subject-Verb Agreement + Meaning

Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that because the various species of anglerfish have evolved to survive in the pitch black darkness and crushing pressure found at the bottom of the ocean, they have developed a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior that enable easy locomotion.

• In a “phrase + comma + noun” construction, the phrase must correctly modify the noun; this is one of the most frequently tested concepts on GMAT sentence correction.
• Two singular nouns joined by “and” function as one plural noun.

A. Correct. This answer choice correctly uses the plural verb “enable” to refer to the plural noun phrase “symbiotic relationship…and inverted swimming behavior”. Further, Option A correctly uses “Having evolved to survive…” to modify “the various species of anglerfish”, conveying the intended meaning- that the various species of anglerfish have evolved to survive in the pitch black darkness and crushing pressure found at the bottom of the ocean.

B. Trap. This answer choice incorrectly uses the singular verb “enables” to refer to the plural noun phrase “symbiotic relationship…and inverted swimming behavior”; please remember, two singular nouns joined by “and” function as one plural noun.

C. This answer choice incorrectly uses “Having evolved to survive…” to modify “developing a symbiotic relationship with bioluminescent bacteria and…”, illogically implying that the action of developing a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior evolved to survive at the bottom of the ocean; the intended meaning is that various specious of anglerfish have evolved to survive at the bottom of the ocean; please remember, in a “phrase + comma + noun” construction, the phrase must correctly modify the noun.

D. This answer choice incorrectly uses “Having evolved to survive…” to modify “developing a symbiotic relationship with bioluminescent bacteria and…”, illogically implying that the action of developing a symbiotic relationship with bioluminescent bacteria and an unusual inverted swimming behavior evolved to survive at the bottom of the ocean; the intended meaning is that various specious of anglerfish have evolved to survive at the bottom of the ocean; please remember, in a “phrase + comma + noun” construction, the phrase must correctly modify the noun.

E. This answer choice incorrectly uses “Having evolved to survive…” to modify “an easy locomotion enabling relationship…”, illogically implying that anglerfishes’ relationships with the bacteria and their inverted swimming behaviors have evolved to survive at the bottom of the ocean; the intended meaning is that various specious of anglerfish have evolved to survive at the bottom of the ocean; please remember, in a “phrase + comma + noun” construction, the phrase must correctly modify the noun.

A is the best answer choice.

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