The region of chromatin which is loosely packed and transcriptionally active is _______

[Molecular-Basis-of-Inheritance] [class-xii ]

• Heterochromatin
• Euchromatin
• Prochromatin
• None
Correct Option: B  [ Euchromatin ]

Remark: Euchromatin is active.

The strand of DNA which is transcribed is called the _______ strand.

[Molecular-Basis-of-Inheritance] [class-xii ]

• Coding
• Template
• Sense
• Non-template
Correct Option: B  [ Template ]

Remark: The template strand is transcribed.

The coding strand has _______ polarity.

[Molecular-Basis-of-Inheritance] [class-xii ]

• 3' to 5'
• 5' to 3'
• Both
• None
Correct Option: B  [ 5' to 3' ]

Remark: The coding strand runs 5' to 3'.

In prokaryotes, the ribosome binding site on mRNA is called _______ sequence.

[Molecular-Basis-of-Inheritance] [class-xii ]

• TATA
• Shine-Dalgarno
• Pribnow
• Enhancer
Correct Option: B  [ Shine-Dalgarno ]

Remark: The Shine-Dalgarno sequence is the ribosome binding site in prokaryotes.

In the presence of lactose, the repressor is inactivated by the _______

[Molecular-Basis-of-Inheritance] [class-xii ]

• Promoter
• Inducer
• Operator
• Regulator
Correct Option: B  [ Inducer ]

Remark: Lactose (inducer) inactivates the repressor.

The enzyme that catalyzes peptide bond formation is _______

[Molecular-Basis-of-Inheritance] [class-xii ]

• Peptidyl transferase
• DNA polymerase
• RNA polymerase
• Ligase
Correct Option: A  [ Peptidyl transferase ]

Remark: The ribosome (23S rRNA) acts as peptidyl transferase.

In eukaryotes, the primary transcript is called _______

[Molecular-Basis-of-Inheritance] [class-xii ]

• mRNA
• tRNA
• rRNA
• hnRNA
Correct Option: D  [ hnRNA ]

Remark: The primary transcript is hnRNA.

The cap added to the 5' end of hnRNA helps in binding of _______

[Molecular-Basis-of-Inheritance] [class-xii ]

• DNA
• Ribosome
• tRNA
• Repressor
Correct Option: B  [ Ribosome ]

Remark: The cap recruits the ribosome.

During translation, the _______ site on the ribosome accepts the incoming aminoacyl-tRNA.

[Molecular-Basis-of-Inheritance] [class-xii ]

• P
• E
• A
• S
Correct Option: C  [ A ]

Remark: The A (Aminoacyl) site accepts new tRNAs.

The peptidyl-tRNA is present at the _______ site of the ribosome.

[Molecular-Basis-of-Inheritance] [class-xii ]

• A
• P
• E
• S
Correct Option: B  [ P ]

Remark: The P (Peptidyl) site holds the growing chain.