21. When composite transposons are formed

A. a small deletion occurs in the transposase gene of an IS element
B. a small deletion occurs in the transposase gene of an IS element and plasmid is integrated
C. an IS element integrates with another IS element with the help of a plasmid
D. two IS elements integrate into a chromosome with only a small distance separating them

22. Which of the following plasmids do not possess information for self-transfer to another cell?

A. Cryptic plasmids
B. Conjugative plasmids
C. Non-conjugative plasmids
D. None of these

23. The term used for acquisition of naked DNA from its environment and its incorporation in their genome by a bacterium is

A. transformation
B. lysogenic conversion
C. conjugation
D. transduction

24. What is the term used for a bacterial cell that is able to take up naked DNA?

A. Complementary
B. Liable
C. Competent
D. Infected

25. Penicillin resistance in staphylococci is acquired due to

A. conjugation
B. mutation
C. transformation
D. transduction