Question

1) Which one of the following would NOT be necessary for an expression vector?

A) Transcription start site

B) Selectable marker

C) Cloning site

D) Chromosome independent replication

E) Antibody binding site

2)A virus that infects a prokaryotic cell is called a bacteriophage or phage. Which of the following mechanisms for introducing DNA into prokaryotic cells involves the use of phage as the vector?

A) Conjugation

B) Transduction

C) Transformation

D) Abrogation

E) Importation

3)The use of epitopes like GST in a fusion protein construct to aid in the eventual purification of the fusion protein by chromatography is most like:

A) Size exclusion chromatography

B) Ion exchange chromatography

C) Agarose gel electrophoresis

D) Southern blot

E) Affinity chromatography

Answer 1

Ans-1- following are the components of expression vectors-

- Multiple Cloning sites

- Origin of replication

- promoter

- operator

- Selection marker

- Ribosomes binding site

- termination codon

there is no need for antibody binding sites, hence this is not the part of the expression vector.

Ans-2- Transduction is the process of lateral or horizontal gene transfer in which the bacterial DNA is moved from one bacteria to another with the help of bacteriophage.

option B (transduction) is the correct answer.

Ans-3- GST tag is attached to the proteins in order to separate the protein by affinity chromatography. GST has a high binding affinity to t=glutathione and retained in the column when the mixture of protein is passed from the column which has glutathione attached to the matrix.

option E ( affinity chromatography) is correct answer.