Food chains show energy transfer between organisms. the size of a food chain can vary, yet there is a limit to the number of levels that a food chain can reach. why is there a limit to the number of levels that a food chain can reach?

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?

Ascientist is examinin the cell is disrupted when she damages one specific type of macromolecule g the function of macromolecules in a cell she notices that movenent of large molecules into and out of

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above