how can oil spills affect the ability of sea birds to acccess resources such as food and shelter? how will other animals that depend on birds for food be affected

Differences between compact bone and cartilage

When explaining dominant and recessive traits to a younger family member, they respond, "well chances are i can probably taste ptc, since dominant traits are more common." how might you address this misconception?

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?