GATE Biotechnology Practice Quiz

Question 1

Which statement best distinguishes a cosmid from a standard plasmid cloning vector?

Accepted Answer

A cosmid carries cos sites that allow in vitro packaging into lambda phage particles

Question 2

A researcher wants high-level inducible expression of a cloned ORF in E. coli using T7 RNA polymerase. Which vector element is essential immediately upstream of the ORF?

Accepted Answer

T7 promoter

Question 3

In homologous recombination-based gene targeting in mouse embryonic stem cells, why is a thymidine kinase (tk) gene often placed outside the homology arms of the targeting construct?

Accepted Answer

To allow negative selection against random integrants using ganciclovir

Question 4

A plasmid isolated from an E. coli dam+ dcm+ strain is digested separately with MboI, DpnI, and Sau3AI. Which pattern is expected for the sequence 5'-GATC-3' present in the plasmid DNA?

Accepted Answer

Cut by DpnI and Sau3AI, but not by MboI

Question 5

For constructing a physical map of a 1.2 Mb genomic region with stable maintenance of large inserts and low chimerism, which vector is most appropriate?

Accepted Answer

BAC vector based on F-factor replicon

Quizzes