Why were Craigie and Mizuuchi able to discover the strand transfer intermediate generated by transposition in Mu?
What will be an ideal response?
RecA is not the only protein that can promote branch migration. One example is called RuvAB. RuvAB:
A. can promote branch migration but the process is very slow.
B. contains two donut-shaped RuvA hexamers, related in structure to DnaB helicase, that have nuclease activity.
C. cleaves the Holliday intermediate by replacing one RuvA with RuvC.
D. can reload DnaB helicase to reprime DNA replication after repair.
E. does not require ATP hydrolysis.
In the presence of DNA-binding protein Sp1, transcription is:
A. increased if H1 is at low levels.
B. decreased if H1 is at low levels.
C. increased if H1 is at high levels.
D. not affected by H1.
In regions of a chromosome that encode highly structured RNA molecules, what sequence characteristics would you expect to find?
A. an abundance of pyrimidines, which play an important role in three-dimensional folding of RNA
B. an abundance of uracil, which plays an important role in three-dimensional folding of RNA.
C. multiple short segments capable of base pairing with adjacent or distant regions of the sequence.
D. heavy methylation of these gene sequences, preventing their expression
E. very little in the way of sequences that can form double-stranded helices
Which of the following does not reflect the action of an effector molecule on the transcription of a gene?
A. An effector binds to a repressor to decrease the level of transcription.
B. An effector binds to a repressor to increase the level of transcription.
C. An effector binds to an activator to increase the level of transcription.
D. An effector binds to a polymerase to increase the level of transcription.
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