Question 1
Which of the following genotypes and conditions will have the
lowest level of
trp operon expression?
◦
trp+ / tryptophan present
◦
trpR- / tryptophan present
◦
trpL- / tryptophan present
◦
trp+ / tryptophan absent
◦
trpP- / tryptophan absent
Question 2
Which of the following is FALSE regarding how bacteria regulate the transcription of stress response genes?
◦ Under extreme growth conditions, such as heat stress and starvation, bacteria can induce transcription of alternative sigma factors.
◦ The
rpoH gene encodes a sigma factor known as σ
32 that is active at high temperatures.
◦ High heat can cause a change in the chaperone proteins.
◦ Transcription is activated by antitermination, which allows transcription to extend into heat shock genes.
◦ Holoenzymes containing an alternative sigma subunit are able to recognize the promoters of genes not transcribed by the common bacterial RNA polymerase.
Stress and Healing of Wounds
Symptoms of Stress
Pseudomonas aeruginosa bacteria showing rod and spore (SEM)
pRB Transcription Factor
Binary fission, the reproductive mode of bacteria and archaea
Cross-regulatory interactions among gap genes