What are the two main classification of ecosystems? a. biotic abiotic b. terrestrial and aquatic c. closed and open d. inputs and outputs

Darrel conducted an experiment with the following procedure: fill two cups with ice water. place an uninflated balloon snuggly onto your left index finger. blow a little air into an identical balloon, and place it onto your right index finger. place both fingers into the cups of ice water. darrel noticed that his right finger felt warmer in the ice water than did his left finger. which of the following does the experiment show? a. air is a good radiator of heat. b. air is a good insulator of heat. c. air is a good conductor of heat. d. air is a good convector of heat.

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?

How much time has elapsed from the very beginning of "the memior of the conquistador bernal diaz del castillo" to the end? a. castillo's whole life b. a quarter of an hour c. a few weeks d. a decade