Gene Expression Test 1

Total Questions:25 Total Time: 45 Min



Questions 1 of 25

Question:Which one of the following is the correct sequence of genes within an operon?

Answers Choices:

Regulator, promoter, operator, structural

Regulator, operator, promoter, structural

Structural, operator, regulator, promoter

Promoter, operator, structural, regulator

Questions 2 of 25

Question:The segment of a DNA molecule determining the amino acid sequence of a protein is known as:

Answers Choices:

Operator gene

Regulator gene

Structural gene

Modifier gene

Questions 3 of 25

Question:The gene that codes for a repressor protein is called:

Answers Choices:




Structural gene

Questions 4 of 25

Question:In the 'Operon concept' the regulator gene regulates chemical reactions in the cell by:

Answers Choices:

inhibiting substrate in the reaction

inhibiting migration of mRNA into cytoplasm

inhibiting transcription of mRNA

 inactivating enzymes in the reaction

Questions 5 of 25

Question:A short sequence of DNA where the repressor binds, preventing RNA polymerase from attaching to the promoter is called:

Answers Choices:





Questions 6 of 25

Question:In operon concept, the operator gene combines with:

Answers Choices:

regulator gene to switch off structural gene transcription

inducer to switch off structural gene transcription

regulator protein to switch on structural gene transcription

regulator protein to switch off structural gene transcription

Questions 7 of 25

Question:In operon model, RNA polymerase binds to:

Answers Choices:

structural gene

regulator gene

operator gene

promoter gene

Questions 8 of 25

Question:Lac operon is related with:

Answers Choices:

synthesis of enzyme of lactose catabolism

synthesis of enzyme of lactose anabolism

synthesis of lac by lac insect

degradation of lac in the body of lac insect

Questions 9 of 25

Question:A gene which synthesises a repressor protein is:

Answers Choices:

Operator gene

Promoter gene

Structural gene

Regulator gene

Questions 10 of 25

Question:When tryptophan is present:

Answers Choices:

transcription of structural genes occurs

the repressor is able to bind to the operator

the repressor is unable to bind to the operator

both (B) and (C) are correct

Questions 11 of 25

Question:Repressor is the product of:

Answers Choices:

Operator gene

Structural gene

Promoter gene

Regulator gene

Questions 12 of 25

Question:During genetic induction, repressor is synthesised from:

Answers Choices:

regulator gene

structural gene

operator site

promoter site

Questions 13 of 25

Question:In operon model, regulator gene:

Answers Choices:

stops the formation of r-RNA

stops the transcription

prevents the movement of RNA

inactivates the substrate

Questions 14 of 25

Question:Gene-Battery model of gene expression in eukaryotes is proposed by:

Answers Choices:

Jacob and Monod

Britten and Davidson

Beadle and Tatum

Kornberg and Ochoa

Questions 15 of 25

Question:In split genes, the coding sequences are called:

Answers Choices:





Questions 16 of 25

Question:RNA processing is:

Answers Choices:

the same as transcription

an event that occurs after RNA is transcribed

the rejection of old, worn-out RNA

both (2) and (3) are correct

Questions 17 of 25

Question:The concept of split gene is that the:

Answers Choices:

DNA in a gene can be split by deoxyribonuc lease

secondary constrictions on the chromo­somes give a split appearance to genes

adjacent genes are separated from each other by spacers

coding sequences in many eukaryotic genes are often separated by non-coding sequences

Questions 18 of 25

Question:This is not produced by E. coli in the lactose medium

Answers Choices:


Lactose permease

Lactose dehydrogenase

Thiogalactoside transacetylase

Questions 19 of 25

Question:At the time of organogenesis, genes regulate the process at different levels and at different time due to

Answers Choices:





Questions 20 of 25

Question:Jacob and Monad studied lactose metabolism in E. coli and proposed operon concept which is applicable for:

Answers Choices:

All prokaryotes

All prokaryotes and all eukaryotes

All prokaryotes and some eukaryotes

All prokaryotes and some protozoans

Questions 21 of 25

Question:Which of the following reunites the exon segments after RNA splicing ?

Answers Choices:

RNA primase

RNA ligase

RNA protease

RNA polymerase

Questions 22 of 25

Question:In E. coli during lactose metabolism, repressor binds to :

Answers Choices:

Operator gene

Promoter gene

Regulator gene

Structural gene

Questions 23 of 25

Question:Exon part of mRNA codes for

Answers Choices:





Questions 24 of 25

Question:RNA polymerase which is on the promoter, moves to the structural genes to transcribe them. However it happens when

Answers Choices:

Regulator gene induces promoter

Inducer binds to structural genes

There is repressor on the operator

There is no repressor on the operator

Questions 25 of 25

Question:Some genes are constantly expressed in the bacterial cells. These genes are called.

Answers Choices:

Active genes

Link genes

Jumping genes

Constitutive genes