In operon concept, regulator gene functions as: from Biology Mol

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 Multiple Choice QuestionsMultiple Choice Questions

331.

The direction of DNA replication is from :

  • amino acid end

  • 3' end towards 5' end

  • 5' end towards 3' end

  • amino terminus to carboxy terminus


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332.

In operon concept, regulator gene functions as:

  • repressor

  • regulator

  • inhibitor

  • initiator


A.

repressor

Operon is defined as a set of genes transcribed under the control of an operator gene. It is a segment of DNA containing adjacent genes including structural genes, an operator gene, and a regulatory gene. An operon is thus a functional unit of transcription and genetic regulation. In operon model, regulator gene directs the synthesis of proteins. It may be an active repressor or an inactive repressor.


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333.

In the lactose operon of Escherichia coli what is the function of promoter

  • Binding of Gyrase enzyme

  • Binding of RNA polymerase

  • Codes for RNA polymerase

  • Processing of messenger RNA


334.

Sex factor in bacteria is

  • F-replicon

  • chromosomal replicon

  • RNA

  • sex pillies


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335.

Most simple amino acid is

  • lysine

  • glycine

  • aspartic acid 

  • nucleic acid


336.

Which of the following be named for DNA produced from RNA?

  • A- DNA

  • B- DNA

  • C- DNA

  • Z- DNA


337.

The length of DNA having 23 base pair is

  • 78 Ao 

  • 78.4 Ao.

  • 74.8 Ao 

  • 78.2Ao


338.

Number of nitrogenous bases in a codon is

  • 2

  • 5


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339.

Chromosomes can be stained with one of the following chemicals

  • acetocarmine 

  • safranine

  • light green

  • eosin


340.

In a DNA molecule, distance between two bases is

  • 2 nm/ 20 Å

  • 0.2 nm/ 2 Å

  • 3.4 nm/ 34 Å

  • 0.34 nm/ 3.4 Å


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