The cell's endomembrane system is most like which system of the human body?

a. digestive

b. integumentary

c. musculoskeletal

d. circulatory

2. which one of these is not an example of intercellular communication?

a. hypothalamus signals pituitary gland

b. ribosomes make protein

c. endocrine cells send hormones into blood

d. bacteria share information about nutrients

What are the two main phases of a cell cycle

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?

What type of appendages do sponges cnidarians roundworms annelids mollusks arthropods echinoderms and vertebrate have? jointed, not jointed, absent