12. Grassland biomes have all of the following EXCEPT A. grass for grazing animals
B. wet season
C. slight temperature range D. wheat fields

13. Deserts have all of the following EXCEPT
A. little rainfall
B. little wind
C. soil with little organic matter D. few large animals

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.

For a comparative or experimental investigation, scientists often make a testable about a scientific question, and then they test it in the investigation. a.control b.hypothesis c.procedure d.system

What is the difference between how ionic and covalent bonds form