Cloning Vectors and Competent Host

The video tutorial explains the use of cloning vectors like plasmids and bacteriophages in genetic engineering. It covers essential features of cloning vectors, such as the origin of replication, selectable markers, and restriction sites. The tutorial discusses insertional inactivation techniques using antibiotic resistance genes and beta-galactosidase. It also explores methods for transforming plant and animal cells using vectors like Agrobacterium and retroviruses. Finally, it describes chemical and physical methods for making cells competent to take up foreign DNA.

What is the primary function of plasmids in bacterial cells?

• To cause mutations

• To provide energy to the cell

• To replicate independently of the bacterial chromosome

• To produce proteins

Which of the following is NOT a feature of an ideal cloning vector?

• Origin of replication

• Selectable marker

• Protein synthesis site

• Recognition sites

How do selectable markers help in genetic engineering experiments?

• They prevent DNA degradation

• They identify transformed host cells

• They increase the replication rate of plasmids

• They enhance the color of bacterial colonies

What happens when a foreign DNA is inserted into the tetracycline resistance gene of PBR 322?

• The plasmid becomes non-functional

• The tetracycline resistance is inactivated

• The plasmid gains additional resistance

• The plasmid replicates faster

What is the role of the beta-galactosidase gene in identifying recombinant cells?

• It produces a blue color when active

• It prevents DNA degradation

• It enhances cell growth

• It provides antibiotic resistance

Which vector is commonly used to transform plant cells?

• PBR 322

• Agrobacterium tumefaciens

• Retrovirus

• Lambda phage

What is the main challenge in transforming cells with DNA?

• DNA is too large to enter cells

• DNA is hydrophilic and cannot easily pass through cell membranes

• DNA degrades quickly inside cells

• DNA causes cell death

Which method involves using electric currents to create pores in cell membranes?

• Chemical transformation

• Electroporation

• Biolistic technique

• Microinjection

What is the purpose of using calcium ions in the chemical method of transformation?

• To increase DNA replication

• To enhance protein synthesis

• To stabilize the cell membrane

• To create pores in the bacterial membrane

Which technique uses high-velocity micro particles to deliver DNA into cells?

• Biolistic technique

• Chemical transformation

• Electroporation

• Microinjection