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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.
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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.
A low level of expression of lac operon occurs at all the time. Justify the statement.
______ refers to the phenomenon by which a set of genes are switched on when there is necessity to metabolise a new substrate.
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.
Which of the following factors regulate gene expression?
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.
Which of the following are the post-transcriptional events in an eukaryotic cell?
- Transport of pre-mRNA to cytoplasm prior to splicing.
- Removal of introns and joining of exons.
- Addition of methyl group at 5' end of hnRNA.
- Addition of adenine residues at 3' end of hnRNA.
- Base pairing of two complementary RNAs.
Choose the correct answer from the options given below:
