# DBT JRF 2020 — Question 25

Exam: DBT JRF 2020 · Section: B · Topic: Molecular Biology · Difficulty: Hard

## Question

Which of the following are NOT transcribed by RNA polymerase II?

## Options

- **A.** miRNA and some snRNA
- **B.** tRNA and 5S rRNA
- **C.** mRNA and snoRNA
- **D.** miRNA and snoRNA

## Answer

Option B

## Explanation

For a linear molecule with 4 atoms A-B-C-D and rotation possible around bond B-C: the dihedral (torsion) angle is defined as the angle between the two planes that share the B-C bond: Plane 1 = the plane containing atoms A, B, C; Plane 2 = the plane containing atoms B, C, D. The dihedral angle is the angle between plane ABC and plane BCD, measured by looking along the B-C axis. In protein biochemistry, backbone dihedral angles $\phi$ (N-Cα bond, defined by C-N-Cα-C plane) and $\psi$ (Cα-C bond, defined by N-Cα-C-N plane) define secondary structure. Note: the correct answer states 'plane ABD and plane ACD' which is an alternative (equivalent) formulation in some conventions.

Source: https://mypyqbuddy.com/questions/which-of-the-following-are-not-transcribed-by-6a05a8a02adafec470293231