Which of the following is not characteristic of all nonvascular plants? a)they produce seeds. b)they produce spores. c)they have a life cycle that involves alternating generations. d)they require water for sexual reproduction.

Which of the following is an example of an environmental change the affected the evolution of life a. volcanic activity b. changes in climate c. mountain building d. all of the above

Name the two stages involved in protein synthesis and explain what occurs in each of the two stages. be sure to also indicate where each process takes place. plz don't give one sentence answers : d

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?