Sydney drew a flow chart to illustrate the nitrogen cycle. Flow chart of the nitrigen cycle. Box 1: uppercase X. Box 2: Bacteria fix nitrogen from the air. Box 3: uppercase Y. Box 4: Consumers eat other organisms. Box 5: Decomposers break down dead organisms. Which labels best complete the flow chart? X: Producers undergo photosynthesis. Y: Nitrogen compounds are released into the air. X: Nitrogen compounds are released into the air. Y: Producers undergo photosynthesis. X: Free nitrogen is in the atmosphere. Y: Producers absorb nitrogen compounds through their roots. X: Producers absorb nitrogen compounds through their roots. Y: Free nitrogen is in the atmosphere.

Which statement about dna replication is true? a. eukaryotes only have one circular chromosome that unwinds at multiple locations. b. eukaryotes can only replicate one segment of a chromosome at a time. c. prokaryotes can only replicate their single circular chromosome in the nucleus. d. prokaryotes only have one origin of replication to initiate replication.

What macromolecule is produced during translation? a. carbohydrate b. rna c. dna d. protein

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?