Amembrane that allows only some materials to pass through shows selective permeability.

Dominant over the mutant vermilion (bright red) allele. a homozygous wild-type female fly is mated with a vermilion male fly. predict the eye colors of f1 and f2 generations. (assume that the f1 flies are allowed to interbreed to produce the f2 generation.)

Body systems are not completely independent they integrate and work together describe one example of the integration between body systems

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?