Which of the following is nottrue of the regulation of the trp operon?
A. Transcription attenuation relies on the fact that bacteria lack a nucleus.
B. The level of tryptophan in the cell regulates the rate of transcription after transcription begins.
C. The level of tryptophan in the cell regulates the rate of transcription before transcription begins.
D. RNA polymerase is recruited to the promoter when tryptophan levels are high.
Which of the following is directly involved in removing Spo11 that is covalently bound to the 5'-ending strand during meiosis?
A. RPA
B. ExoI
C. Rad50
D. Sgs1
E. Dmc1
The bacterium Deinococcus radiodurans is able to withstand the damage incurred by exposure to very high levels of irradiation. This exposure introduces many double-stranded breaks that are repaired within hours.
Which of the following is a key component of this rapid repair mechanism?
A. RecA
B. extended synthesis-dependent strand annealing (ESDSA)
C. synthesis-dependent strand annealing (SDSA)
D. double-strand break repair (DSBR)
E. XerCD
H1 binding to DNA is different than that of the other four histones because H1 binds to:
A. the major groove of the DNA only.
B the DNA as it comes off both sides of the nucleosome.
C. as a component of the octamer; however, unlike H2A, H3, and H4, H1 lacks the histone tail.
D. one strand of the linker DNA as it comes off the nucleosome and binds a second site in the central region of the DNA supercoil.
E. the DNA as a homotetramer.
Which one of the following statements about the denaturation of nucleic acids is true?
A. Increasing the temperature will allow the DNA to renature.
B. Returning the pH to 7 will allow the DNA to denature.
C. Reducing the temperature will often allow a denatured DNA to renature.
D. Increasing pH allows annealing of RNA strands.
E. Since RNA is only partially double-stranded it is unaffected by changes in pH and temperature.
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