In a normal-sighted individual, the will focus images perfectly on a small indentation in the back of the eye known as the .

92 sathe best for the question 11. most animals and plants reproduce sexually. this means that dna is passed down to new organisms from two parental organisms. which of the following is a key advantage of sexual reproduction?

Which statement correctly describes a way that mutations increase the likelihood that a species will survive in a changing environment

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?