While touring a Costa Rican rain forest on vacation, Dana learns that rain forests have the highest biodiversity of any ecosystem on the planet. The guide defines the term biodiversity for the group. Which definition does she give

Which of the following is something every person can do plz asap apex

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 of the following is the earliest era of earth's geologic time scale? cenozoic mesozoic precambrian paleozoic