The endosymbiosis hypothesis proposes that a. a small cell lived inside a larger cell to the benefit of both cells. b. two cells merged into one cell, improving the enzyme function of the new cell. c. two separate cells worked cooperatively and one benefited from the other. d. a large cell engulfed and digested a smaller cell, exposing its enzymes for use by the larger cell. r

Describe how alleles and genes are related

Deer cave cannot support photosynthesis is as not enough sunlight is present. in spite of this, it still has a complex food chain. what is the energy foundation of this food chain?

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?