16. Which of these mechanisms for thymine dimers repair lead to mutations?

A. Excision repair
B. Photoreactivation
C. SOS repair
D. Never leads to mutation

17. Frame shift mutation may occur as a result of

A. formation of a thymine-dimer
B. deamination of cytosine to uracil
C. conversion of guanine to xanthine
D. none of the above

18. Thymine dimers are directly repaired with the help of visible light by process known as

A. phosphorylation
B. excision repair
C. photosynthesis
D. photoreactivation

19. The promoter on an expression vector used to overproduce proteins in bacteria is

A. a bacterial promoter
B. expressed both in bacteria and mammalian cells
C. not a regulated promoter
D. the natural promoter of the gene being cloned

20. Differentiation of four different bases in automated sequencing systems is that each base has

A. different radioactive tag
B. cytosine at start
C. unique antibody bound to it
D. distinctive fluorescent tag