13a. An embryo begins as a single cell. If each cell divides each day, then the number of cells will double each day. Every 10 days, the number of cells will be multiplied by 1000 = 10^3 every 10 days, approximately how many cells will there be after 20 days of cell division? 13.b Approximately how many cells will there be after 40 days of cel division?

Please explain how you got the answer.

What is a traditional chinese touch therapy involving finger pressure applied to specific areas of the body to restore the flow of qi.

What did hunter gathers do to alter the 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?