Which of the following best explains how subsoil becomes rich in minerals? A.
Volcanic activity heats the rock fragments in the subsoil and releases minerals.
B.
Minerals from the topsoil leach down into the subsoil.
C.
Groundwater flows through the subsoil and deposits minerals.
D.
The bedrock below the subsoil is broken down into smaller particles.

Select all the true statements about the cosmic microwave background radiation

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?

Creating new things to solve problems and improve life depends on the close interaction of which two fields?