17 public questions tagged with this topic.
Plasmid vectors are used in genetic engineering to transfer foreign genes into host cells, where they_x000D_ replicate independently.
Ref: NCERT Class 12 Biology Chapter 10: Biotechnology and its Applications Biosafety and Overview of Applications
Cloning is the process of producing identical genetic copies of organisms or cells.
Ref: NCERT Class 12 Biology Chapter 10: Biotechnology and its Applications Medical Applications - Molecular Diagnosis - PCR ELISA
Somaclones are genetically identical plants produced through micropropagation.
Ref: NCERT Class 12 Biology Chapter 10: Biotechnology and its Applications Agricultural Applications - Nutritional Enhancement - Golden Rice and GM Crops
Polymerase Chain Reaction (PCR) is used to amplify specific DNA sequences, producing multiple copies of a gene.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Polymerase Chain Reaction - PCR and Applications
PCR is a rapid method for amplifying DNA sequences within hours, unlike traditional cloning, which takes days or weeks.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Polymerase Chain Reaction - PCR and Applications
DNA polymerase is used to synthesize new DNA strands by adding nucleotides to a growing DNA chain, making it essential for DNA replication and PCR.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Polymerase Chain Reaction - PCR and Applications
Escherichia coli is commonly used as a host for cloning due to its well-studied genetics and rapid growth.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Competent Host and Gene Transfer Methods
Selectable markers, such as antibiotic resistance genes, allow for the identification of recombinant bacterial cells.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Cloning Vectors - Plasmids Phages Cosmids Selectable Markers Ori
Vectors are DNA molecules that carry foreign genes into host cells for replication and expression.
Ref: NCERT Class 12 Biology Chapter 9: Biotechnology: Principles and Processes Cloning Vectors - Plasmids Phages Cosmids Selectable Markers Ori
In cloning design, compatibility of cohesive termini determines insert-vector joining. Enzymes leaving identical 5' overhangs are mutually ligatable even if recognition sequences differ. SalI-hindII context implies need for compatible pair. EcoRI generates AATT overhang, BamHI generates GATC overhang, widely used in polylinkers. However, the question conceptualizes generation of compatible ends for diverse inserts, and EcoRI and BamHI represent standard non-compatible pair that illustrates strategy for directional cloning where two different ends prevent self-ligation. Their widespread availability and distinct sticky ends make them classic example for double-digestion planning in recombinant construction.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
Plasmid propagation depends on origin of replication, a cis-acting DNA element recognized by host replication machinery. Ori contains AT-rich duplex unwinding element, DnaA boxes, and binding sites for host initiation factors that recruit helicase, primase, and DNA polymerase III holoenzyme for autonomous bidirectional replication independent of chromosomal replication. Without functional origin, plasmid cannot duplicate and is lost during cell division. LacZ, promoter, and reporter genes control phenotype or expression but do not confer replication ability. Copy number is also regulated by elements within ori region.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
Successful blue-white selection requires three supplements to Luria-Bertani agar besides routine nutrients for bacterial growth. Ampicillin ensures plasmid retention by selecting bla-positive transformants and inhibiting cell wall synthesis in plasmid-free segregants. Isopropyl β-D-1-thiogalactopyranoside, a non-hydrolyzable lactose analog, derepresses lac operon by inactivating LacI repressor, inducing strong expression of plasmid-borne lacZα. X-gal provides chromogenic substrate; cleavage by β-galactosidase yields insoluble blue precipitate. Combined medium permits simultaneous positive selection for plasmid presence and colorimetric screening for insertional inactivation, distinguishing recombinant white colonies from non-recombinant blue colonies.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
