SC (embryo development)

[Vignesh.4384]

Biologists believe that they have found one of the substances that tell individual genes both when to become active and when to remain quiescent in the earliest phases of an embryo’s development.
(A) tell individual genes both when to become active and when to remain
(B) tell individual genes both at which time they should become active or should remain
(C) tells individual genes both when to become active or remain
(D) tells individual genes both when to become active or when to remain
(E) will tell an individual gene both about when it should become active and remain

Hi,
For the above question i chose option C but the correct options is A.
Can any one pls tell me why it is A ?

[varunrajwade]

A is correct..

The reason is the construction "one of the" is followed by a plural noun (genes) and hence will take a plural verb form i.e. tell... Hence remove all options except A and B... B is an awkward sentenece, so A...

Following is from Sahil's SC notes:-

pattern to remember is ‘one of the NOUN (this noun will always be plural) + that/who + PLURAL VERB

Varun

[Vignesh.4384]

Thank You

[rey.fernandez]

A notable difference between A and C is the use of idiom "both X and Y" in A (correct) and the use of "both X or Y" in C (incorrect). Also, in A, the X and Y in "both X and Y" are parallel, a requirement for these idiomatic forms.