The lagging strand is synthesized in the direction _______

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

• 5' to 3'
• 3' to 5'
• Both
• Random
Correct Option: A  [ 5' to 3' ]

Remark: All DNA synthesis occurs 5' to 3', even on the lagging strand (away from fork).

DNA ligase joins DNA fragments by forming a _______ bond.

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

• Hydrogen
• Peptide
• Phosphodiester
• Glycosidic
Correct Option: C  [ Phosphodiester ]

Remark: Ligase forms phosphodiester bonds.

_______ relieves the tension created by unwinding of DNA.

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

• Helicase
• Topoisomerase
• Ligase
• Primase
Correct Option: B  [ Topoisomerase ]

Remark: Topoisomerase (Gyrase) relieves supercoiling tension.

In prokaryotes, there is _______ origin of replication.

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

• One
• Two
• Multiple
• None
Correct Option: A  [ One ]

Remark: Prokaryotes typically have a single origin (ori).

In eukaryotes, there are _______ origins of replication.

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

• One
• Two
• Multiple
• Zero
Correct Option: C  [ Multiple ]

Remark: Eukaryotes have multiple origins to speed up replication.

The DNA dependent RNA polymerase catalyzes polymerization in _______ direction.

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

• 3' to 5'
• 5' to 3'
• Both
• Random
Correct Option: B  [ 5' to 3' ]

Remark: RNA synthesis is also 5' to 3'.

The template strand has _______ polarity.

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

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

Remark: The template is read 3' to 5'.

A gene is a segment of DNA that codes for _______

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

• RNA
• Protein
• Both
• None
Correct Option: C  [ Both ]

Remark: A gene codes for functional RNA (tRNA, rRNA) or protein (via mRNA).

In eukaryotes, the genes are _______ (interrupted).

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

• Continuous
• Split
• Polycistronic
• Circular
Correct Option: B  [ Split ]

Remark: Eukaryotic genes are split by introns.

The RNA polymerase I transcribes _______ RNA.

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

• m
• t
• r
• sn
Correct Option: C  [ r ]

Remark: Pol I makes rRNA.