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26
MCQ (Single Correct Answer)

The amino acid attaches to the $t$ RNA at its

A

5'-end

B

3'-end

C

Anti codon site

D

DHU loop

27
MCQ (Single Correct Answer)

To initiate translation, the $m$ RNA first binds to

A

the smaller ribosomal sub-unit

B

the larger ribosomal sub-unit

C

the whole ribosome

D

No such specificity exists

28
MCQ (Single Correct Answer)

In E. coli, the lac operon gets switched on when

A

lactose is present and it binds to the repressor

B

repressor binds to operator

C

RNA polymerase binds to the operator

D

lactose is present and it binds to RNA polymerase

29

What is the function of histones in DNA packaging?

Explanation

Functions of histones in DNA packaging are

(i) Histones as units of octamer participate in primary packaging of DNA.

(ii) Basic histone proteins neutralise the acidic DNA molecule.

30

Distinguish between heterochromatin and euchromatin. Which of the two is transcriptionally active?

Explanation

Densely packed and dark stained chromatin regions are called hetorochromation, while, loosely packed light stained regions are called euchromatin.

Euchromation is transcriptionally active and is transcribed into mRNA. Due to very tight coiling heterochromatin can not be transcribed and is inert/inactive form.