The table below describes three different regions of an ocean ecosystem. Zone
Description
Zone 1 Air, sun, and water exposure; crashing waves.
Zone 2 Water depth less than 200 meters; lots of
sunlight; relatively warm water.
Zone 3 Very deep water; no light; cold except near the
thermal vents that emit heat and chemicals.
Based on table, which of the following is a valid conclusion?
A. There are no producers in Zone 3 that rely on photosynthesis.
B. Organisms in Zone 1 must be able to withstand very cold water.
C. Organisms in Zone 3 must be able to tolerate occasional air exposure
D. The warm water and abundant sunlight in Zone 2 limits the plankton population

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?

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome

What is a limitation of using a chemical formula, such as c6h1206, to represent a compound? the chemical formula does not show the types of elements that make up the compound. the chemical formula does not show how the atoms are connected to one another the chemical formula does not show the number of atoms of each element in a molecule. the chemical formula does not show the chemical symbols of the elements in the compound