The first phase of translation involves the _______ of amino acids.

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

• Polymerization
• Activation
• Degradation
• Transport
Correct Option: B  [ Activation ]

Remark: Amino acids are activated using ATP.

The activated amino acids are linked to their specific tRNA, a process called _______

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

• Transcription
• Charging
• Splicing
• Capping
Correct Option: B  [ Charging ]

Remark: This is charging or aminoacylation of tRNA.

The cellular factory responsible for synthesizing proteins is the _______

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

• Nucleus
• Ribosome
• Mitochondria
• Golgi
Correct Option: B  [ Ribosome ]

Remark: Ribosomes are the site of protein synthesis.

The ribosome consists of structural RNAs and about _______ different proteins.

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

• 40
• 60
• 80
• 100
Correct Option: C  [ 80 ]

Remark: Ribosomes contain rRNAs and about 80 different proteins.

A translational unit in mRNA is the sequence of RNA that is flanked by the start codon and the _______ codon.

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

• Stop
• Promoter
• Terminator
• Operator
Correct Option: A  [ Stop ]

Remark: The coding region is between start and stop codons.

The untranslated regions (UTRs) are present at both 5' end (before start codon) and _______ end (after stop codon).

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

• 3'
• 2'
• 1'
• 4'
Correct Option: A  [ 3' ]

Remark: UTRs are at both ends of the mRNA.

In prokaryotes, control of the rate of _______ initiation is the predominant site for control of gene expression.

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

• Replication
• Transcriptional
• Translational
• Post-translational
Correct Option: B  [ Transcriptional ]

Remark: Transcription initiation is the main control point.

The Lac operon was elucidated by _______ and Monod.

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

• Watson
• Crick
• Jacob
• Hershey
Correct Option: C  [ Jacob ]

Remark: Jacob and Monod described the Lac operon.

The Lac operon consists of one regulatory gene (the i gene) and _______ structural genes.

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

• One
• Two
• Three
• Four
Correct Option: C  [ Three ]

Remark: There are three structural genes: z, y, and a.

In the Lac operon, the i gene codes for the _______ of the operon.

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

• Inducer
• Promoter
• Repressor
• Operator
Correct Option: C  [ Repressor ]

Remark: The i gene codes for the repressor protein.