now you’ll examine an operon that undergoes negative and positive control. the ara operon in e. coli codes for enzymes that metabolize the sugar arabinose, which e. coli can use for energy. as you can see in the diagram, the regulatory protein arac can act as both an activator and a repressor of the ara operon.

the bullets go in this order.

4, 1, 3, 5, 2

answertheory;

the correct answer is:

they show how organic molecules could be made from earth's early atmosphere.  

explanation:

the miller–urey experiment lasted a chemical experiment that mimicked the forms created at the time to be present on the early earth and tested the chemical element of life under those circumstances. the experiment confirmed alexander oparin's and j. b. s.