You have a bacterial strain with a mutation that removes the transcription termination signal from the Abd operon. Which of the following statements describes the most likely effect of this mutation on Abd transcription?
(a) The Abd RNA will not be produced in the mutant strain.
(b) The Abd RNA from the mutant strain will be longer than normal.
(c) Sigma factor will not dissociate from RNA polymerase when the Abd operon is being transcribed in the mutant strain.
(d) RNA polymerase will move in a backward fashion at the Abd operon in the mutant strain.
(b) Without the termination signal, the polymerase will not halt and release from the DNA template at the normal location when transcribing the Abd operon. Most probably, the polymerase will continue to transcribe RNA until it reaches a sequence in the DNA that can serve as a termination sequence, either from the next downstream operon or in the intervening sequence between the Abd operon and the next operon. Dissociation of sigma factor occurs once an approximately 10-nucleotide length of RNA has been synthesized by RNA polymerase and should not be affected by the lack of a termination signal [choice (c)].
You might also like to view...
In many areas of the world, humans are destroying habitats at an alarming rate. Why is habitat destruction so dangerous?
What will be an ideal response?
Which hormone stimulates insect growth and molting?
a. ecdysiotropin b. juvenile hormone c. histamine d. pheromone e. ecdysone
Nucleic acids are assembled in the ________ direction
Fill in the blank(s) with the appropriate word(s).
Dandelions, Taraxacum officinale, are plants that asexually produce fruitlike propagules. Sexual reproduction is very rare in this organism. Which species concept would be LEAST useful in defining dandelions as a species?
A. Ecological species concept. B. Biological species concept. C. Both the evolutionary and ecological species concepts. D. Evolutionary species concept. E. Phylogenetic species concept.