Lice attach to human hair and enjoy the warmth given off by the human. They eat
tiny amounts of human blood, causing the human to have little red bumps that
are quite itchy. They may also transmit diseases to a human.

A mutualism
B commensalism
C competition
D parasitism

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?

Paint and solvents pose no potential hazard to human health. select the best answer from the choices provided t f

Babies with very low or very high birth weight are less likely to survive. observe a graph of the data.