NEETZoologyMolecular Basis of Inheritance
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The promoter in a transcription unit is said to be located towards the 5'-end (upstream) of the structural gene. Reason (R): The reference for defining the upstream and downstream ends is made with respect to the polarity of the coding strand. In the light of the above statements, choose the most a
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is incorrect
- D(A) is incorrect but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Assertion (A) is correct as the promoter is located towards the 5'-end (upstream) of the structural gene. Reason (R) is also correct and explains the Assertion. By convention, all reference points in a transcription unit are made with respect to the coding strand. Since the coding strand has a 5' to 3' polarity, its 5'-end is considered the upstream end where the promoter is located. Therefore, both (A) and (R) are correct and (R) is the correct explanation of (A). Answer: Both (A) and (R) are correct and (R) is th