Given below are two statements. Statement I: Restriction enzyme BamHI has its recognition site in tetR region of pBR322. Statement II: E.coli having pBR322 with a desired DNA if inserted at BamHI site can grow in medium containing tetracycline. In the light of the above statements, choose the correct answer from the options given below.
Statement I is true, but Statement II is false
pBR322 is an E. coli cloning vector carrying an origin of replication (ori), the rop gene and two antibiotic-resistance genes, ampR for ampicillin and tetR for tetracycline. The recognition sites of restriction enzymes such as BamHI and SalI lie within the tetR gene, while those of PstI and PvuI lie within ampR.
Statement I is true: the BamHI recognition site of pBR322 lies in the tetR region.
Statement II is false: a desired DNA ligated at the BamHI site interrupts the tetR gene (insertional inactivation). The recombinant plasmid therefore loses tetracycline resistance, and E. coli carrying it cannot grow on a medium containing tetracycline, although it still grows on ampicillin; this difference is used to select recombinants.
Since one statement is true and the other false, the combinations calling both true, both false, or only Statement II true are ruled out.
Statement I is true, but Statement II is false option is correct.
Similar Questions
Given below are two statements
Statement I: Adenosine deaminase is crucial for the immune system to function.
Statement II: Adenosine deaminase deficiency can be cured only by bone marrow transplantation.
In the light of the above statements, choose the correct answer from the options given below.
Given below are the sequence of events in the production of human insulin by Eli Lilly.
a) Preparation of two DNA sequences corresponding to chain A and B of human insulin.
b) Production of chain A and B separately.
c) Introduction of chains in plasmids of E.coli.
d) Extraction of chain A and B combining them by creating disulphide bonds.
Choose the correct sequence of events.
The human protein obtained from transgenic animals used to treat emphysema is
Match List I with List II
List I List II a) Visualization of DNA in gel electrophoresis i) Chitinase b) Precipitation of DNA ii) Lysozyme c) Breaking of cell wall of bacteria iii) Chilled ethanol d) Breaking of cell wall of fungus iv) Ethidium bromide Codes:
Technique to alter the chemistry of genetic materials, DNA and RNA, to introduce these into host organism and change the phenotype of the host is
Important Questions from Biotechnology
- Insertion of a foreign DNA at BamHI site in an E. coli cloning vector pBR322 results in the loss of antibiotic resistance towards :
- Which of the following statements are not true regarding restriction endonucleases ?
A. They are called molecular scissors.
B. These are the enzymes responsible for restricting the growth of bacteriophages in E. coli.
C. They cut the DNA only at the centre of the palindromic sites.
D. They remove nucleotides only from the ends of DNA fragments.
E. They recognise specific palindromic base-pair sequences.
Choose the correct answer from the options given below : - Which of the following statements are correct with respect to DNA separation, isolation and visualization ?
A. The cutting of DNA is done by molecular scissors.
B. The DNA fragments separate according to their size in an agarose gel, upon electrophoresis.
C. The separated DNA fragments can be seen without staining when exposed to UV light.
D. The separated DNA fragments, when stained with ethidium bromide, can be seen in visible light.
Choose the correct answer from the options given below : - Match List I with List II :
List I List II A. Genetically modified organism I. Agrobacterium tumefaciens B. Thermostable DNA polymerase II. Bt cotton C. Ti plasmid III. Thermus aquaticus D. pBR322 IV. Escherichia coli
Choose the correct answer from the options given below : - Identify the correct sequence of steps in each cycle of Polymerase Chain Reaction :
