The cell membrane regulates which materials are allowed to enter and exit a cell by allowing some materials into the cell, but not everything, making it

a. fully permeable
b. semi permeable
c. not permeable

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?

Clues to ecological principles are given in numerous passages of the bible. a bible study of ecology actually opens the doors to better understanding of god's love and concern for the earth. use a concordance to locate bible passages associated with words concerning our stewardship of the earth. you may use a dictionary to find synonyms for these words: dominion replenish subdue judgment stewardship find each of the passages using these words related to principles of ecology. list all passages by quote, book, chapter, and verse under each word. use your own interpretation to rewrite what you think each verse is saying. after your discussion of each of these words, ask one other person to explain his understanding of the word and a related verse without any hints. summarize what he tells you. a concluding paragraph for each of the words should be written noting similarities and differences between your interpretation and that of each person consulted.

When the cell concentrates potassium within, against the natural tendency of matter, it is performing a.passive diffusion b.facilitated diffusion c.active transport d.pinocytosis