2. A high tide occurred at 6:00 a. m. at a beach on Long Island. The next high tide at
this same beach would occur at
approximately
(1) 12:15 p. m. on the same day
(2) 6:30 p. m. on the same day
(3) 12:45 p. m. on the following day
(4) 7:00 a. m. on the following day

The image shows embryos of three vertebrate classes

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?

Anurse is caring for a 42-year-old client who is scheduled for an amniocentesis during the fifteenth week of gestation because of concerns regarding down syndrome. what other fetal problem does an examination of the amniotic fluid reveal at this time?