The z gene codes for _______

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

• Permease
• Transacetylase
• Beta-galactosidase
• Repressor
Correct Option: C  [ Beta-galactosidase ]

Remark: The z gene codes for beta-galactosidase.

The y gene codes for _______

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

• Beta-galactosidase
• Permease
• Transacetylase
• Inducer
Correct Option: B  [ Permease ]

Remark: The y gene codes for permease.

The a gene codes for _______

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

• Beta-galactosidase
• Permease
• Transacetylase
• Repressor
Correct Option: C  [ Transacetylase ]

Remark: The a gene codes for transacetylase.

Lactose is the substrate for the enzyme beta-galactosidase and it regulates switching on and off of the operon. Hence, it is termed as _______

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

• Repressor
• Inducer
• Inhibitor
• Promoter
Correct Option: B  [ Inducer ]

Remark: Lactose acts as the inducer.

The repressor of the operon is synthesized from the _______ gene.

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

• z
• y
• a
• i
Correct Option: D  [ i ]

Remark: The i gene produces the repressor.

The repressor binds to the _______ region of the operon and prevents RNA polymerase from transcribing.

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

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

Remark: The repressor binds to the operator region.

Regulation of lac operon by repressor is referred to as _______ regulation.

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

• Positive
• Negative
• Neutral
• Feedback
Correct Option: B  [ Negative ]

Remark: It is negative regulation because the repressor turns it off.

The Human Genome Project was a 13-year project coordinated by the U.S. Department of _______ and the National Institutes of Health.

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

• Agriculture
• Energy
• Defense
• Education
Correct Option: B  [ Energy ]

Remark: US Dept of Energy and NIH coordinated the HGP.

The method of identifying all genes that are expressed as RNA is referred to as _______

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

• Sequence Annotation
• Expressed Sequence Tags
• DNA fingerprinting
• Gene mapping
Correct Option: B  [ Expressed Sequence Tags ]

Remark: ESTs focus on expressed genes.

The blind approach of simply sequencing the whole set of genome is called _______

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

• ESTs
• Sequence Annotation
• Cloning
• PCR
Correct Option: B  [ Sequence Annotation ]

Remark: Sequencing the whole genome is Sequence Annotation.