● The Preamble of the Indian constitution is amended only once by the 42^nd Amendment Act 1976. This Amendment amended Preamble and also changed the description of India from a ‘Sovereign, Democratic Republic’ to a ‘Sovereign, Socialist, Secular and Democratic Republic’, as well as it also changed the words ‘unity of the nation’ to ‘unity and integrity of the Nation’.

● Adaptive radiation (divergent evolution) is the evolution of different species in a given geographical area, starting from a point and literally radiating to other areas of geography (habitats).

● Adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic interactions, or opens new environmental niches.

Conclusions:

I. Some pencil are pen. (it is a definite case, hence true)

II. All sharpener are pen (it is not a definite case hence false.)

So, Only conclusions I follows.

Hence, option B is the correct answer.

 The pattern is: take the sum of the place value of the respective letters and then multiply the number with the total number of the letters.

RUBY - (18 + 21 + 2 + 25) × 4 = 264

PAY - (16 + 1 + 25) × 3 = 126

Similarly,

RUPAY - (18 + 21 + 16 + 1 + 25) × 5 = 405

Hence, the correct response is option C.

● Swami Vivekananda - Ramakrishna Mission is the correctly matched pair of the founder and the social/socio-religious organization founded.

● He founded the Ramakrishna Math.

● He is regarded as a patriotic saint.

● The birthday of Swami Vivekananda is celebrated as National Youth Day.

Here A : B = 5 : 2

Let A = 5x and B = 2x

If 4 is added to each number then ratio becomes 9 : 4.

So the numbers are:

A = 5(10) = 50 and B = 2 (10) = 20

Hence if:

If 5 is subtracted from each of the original numbers.

The ratio is 3 : 1

Here it is given that

Then

Hence PR = 24 cm

The given sentence is of present perfect tense and it is in the active form.

The structures for active/passive voices are :-
Active Voice :- Subject + has/have + verb (IIIrd form) + object...
Passive Voice :- Object + has/have + been + verb (IIIrd form) + by + subject...
So, the passive voice of the given sentence would be:- A new version of Shakespeare's 'Macbeth' has been performed by the students.
Hence, option C is the correct answer.

The underlined segment is erroneous.

The given sentence implies that the subject's quality of work will be determined if he would get the promotion.

The phrase 'depend upon' means 'to be determined or decided by (something)'. For example, the stamp's value depends on how rare it is.

Also, the subject, promotion, in the sentence is singular. Therefore, the verb must be singular to maintain the subject verb agreement.

Hence, the underlined segment should be replaced with 'depends upon' to make the sentence grammatically correct.