Question

Consider these following sentences and choose the correct ones.
I. Each gene contains a specific promoter region and a leader sequence for guiding the beginning of transcription.
II. Only one strand for DNA, called template strand is copied by RNA polymerase this strand runs in $3^{\prime }\to 5^{\prime }$ direction.
III. RNA polymerase adds complementary nucleotides forming single strand mRNA in $3^{\prime }\to 5^{\prime }$ direction.
IV. Section of DNA that has been transcribed is rewound into its original configuration.

• A. II, III and IV
• B. II and IV
• C. I, II and IV
• D. I, II, III and IV

Answer 1

The correct option is D I, II, III and IV

A promoter is a DNA region that initiates the process of gene transcription. The leader sequence is the introductory region of the mRNA and is also involved in transcription initiation. The template strand runs in the 3' $\to$ 5' region. It is involved in transcription and is copied by RNA polymerase that adds complementary nucleotides forming single strand mRNA in the 3' $\to$ 5' direction. The polymerase continues transcription till it reaches the termination site and the transcribed section of DNA is rewound into its original configuration.

Thus the correct answer is option D.