10. Given below are four sentences with blanks (labeled X, Y, Z and L).
A. RNA Pol I transcribes X.
B. miRNA genes are transcribed by Y.
C. The RNA polymerase found only in plants is Z.
D. tasiRNAs are synthesized by L.
Which one of the following options would present the combination of all terms (in the order X, Y, Z and L) to complete the above sentences correctly
(1) X-mRNAs; Y-RNA Pol II; Z-RNA pol IV; L-RNA Pol III
(2) X-tRNAs; Y-RNA Pol III; Z-RNA pol V; L-RNA Pol I
(3) X-45S rRNA; Y-RNA Pol II; Z-RNA pol V; L-RNA Pol II
(4) X-18S rRNA; Y-RNA Pol V; Z-RNA pol IV; L-RNA Pol I

RNA Polymerases and Their Functions: CSIR NET Life Science PYQ Explained

Correct Answer

(3) X-45S rRNA; Y-RNA Pol II; Z-RNA pol V; L-RNA Pol II

Detailed Explanation

Let’s fill in each blank step by step:

A. RNA Pol I transcribes X.

• RNA Polymerase I is responsible for transcribing the large rRNA precursor, known as 45S rRNA in eukaryotes. This precursor is later processed into 18S, 5.8S, and 28S rRNAs.

  • X = 45S rRNA

B. miRNA genes are transcribed by Y.

• miRNA genes are transcribed by RNA Polymerase II in eukaryotes.

  • Y = RNA Pol II

C. The RNA polymerase found only in plants is Z.

• Plants have two additional RNA polymerases: RNA Pol IV and RNA Pol V, which are not found in animals or fungi. Among the options, RNA Pol V is the correct answer for a plant-specific polymerase in this context.

  • Z = RNA Pol V

D. tasiRNAs are synthesized by L.

• tasiRNAs (trans-acting small interfering RNAs) are a class of small RNAs in plants. Their precursors are transcribed by RNA Polymerase II.

  • L = RNA Pol II

So, the correct combination is:
X-45S rRNA; Y-RNA Pol II; Z-RNA pol V; L-RNA Pol II
(Option 3)

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Summary:
The correct answer is Option 3: X-45S rRNA; Y-RNA Pol II; Z-RNA pol V; L-RNA Pol II. For more free resources, expert video solutions, and the best study materials, trust Let’s Talk Academy for your CSIR NET Life Science journey!