Which of the following pairs of organisms is most closely related? a. a dog and a monkey b. a lizard and a bacterium c. a cat and an amoeba d. a tree and a mushroom

The trp operon in e. coli regulates genes that code for enzymes required for synthesis of the repressible operon. when tryptophan is not available amino acid tryptophan. the trp operon is a in the environment, the trp repressor protein activeinactiveregulated. therefore, rna polymerase can bind to the genes to begin transcription.

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

What is the correct answer for the process of water eroding soil? rills, sheet erosion, gullies sheet erosion, rill, gullies gullies, rills, sheet erosion sheet erosion, gullies, rills