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प्रश्न
The image below shows the result of plating bacteria in a chromogenic medium after incorporating the gene of interest in the plasmid. Some plates had blue colonies; some plates had white colonies. A single bacterium extracted from Plate I, II, and III is shown below:
On the basis of your observations:
- Identify the plate(s) which is/are white. Give a reason.
- Identify the plate(s) which is/are blue. Give a reason.
उत्तर
- Plate I, the b-galactosidase enzyme is responsible for the blue colour. Gene is inserted in the b-galactosidase site of the plasmid, thereby causing insertional inactivation of the enzyme, so no blue colour is made.
- Plate II - Gene of interest not inserted in the plasmid.
Plate III - No plasmid
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संबंधित प्रश्न
When lactose is present in the culture medium:
In E.coli, three enzymes β- galactosidase, permease and transacetylase are produced in the presence of lactose. Explain why the enzymes are not synthesized in the absence of lactose.
Distinguish between structural gene, regulatory gene and operator gene.
A low level of expression of lac operon occurs at all the time. Justify the statement.
Identify the process described in the following paragraph.
Repressible regulation of gene is seen when the end product of a biosyntbetic pathway like amino acid, is provided in the medium. At this time, internal biosynthesis of amino acid stops. It is negative control so the metabolite (amino acid) turns off a set of genes involved in producing that metabolite.
Genes that are involved in turning on or off the transcription of a set of structural genes are called ______.
Which of the following statements is correct about the role of regulatory proteins in transcription in prokaryotes?
Sometimes cattle or even human beings give birth to their young ones that are having extremely different sets of organs like limbs/position of eye(s) etc. Comment.
The gene which codes for enzyme β-galactosidase ______.
List the changes that the primary transcript undergoes to become functional mRNA.