These are fossils of a fish (vagrant pelagic vertebrate; sample a), and a coral (sessile benthic cnidarian; sample b). in general, which would be more useful in paleobathymetry (estimation of past water depth), and why?

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Which statement best describes how the loudness of the sound affects the high-pressure region created by the sound wave? a. a louder sound has no effect on the pressure created. b. a louder sound means a high-pressure region that is higher. c. a louder sound means a high-pressure region that is not as high.

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?