Stanley miller set out to test the hypothesis that the chemicals that harold urey proposed were present in earth's early atmosphere could recombine through chemical reactions to produce organic molecules required for life on this planet. the reactant in stanley miller's experiment would need to form new chemical bonds in order to result in new products being made.

How are organisms in the domain eukarya different from those in the domain archaea? o a. eukaryotes have a cell wall. o b. eukaryotes have mitochondria. o c. eukaryotes have more than one cell. o d. eukaryotes have dna. submit

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?

African penguins, which inhabit the coasts of southern africa, were classified as an endangered species in 2010. two significant threats to their survival are ecosystem damage from oil spills and overfishing by humans. overfishing depletes the food supply of african penguins. the best method to reduce the threat of overfishing would be to . the risk of oil spills could be reduced by increasing the use of , which should oil consumption. if an oil spill does occur, could be used to remove the oil so the ecosystem may more quickly recover.