Which of these best describes the tiny leg bones that some whales have, which do not aid in their movement or serve any other function? O structures that grow and improve in function as they are used
O structures that function at certain times of the year or under certain conditions
O structures that will become adaptations when the environment changes
O structures that have lost all or most of their function over evolutionary time

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?

Penelope studies how the structure and function of the nervous system is related to behavior. she is a psychologist

Scientific evidence is most likely to be consistent if it is based on data from