What accounts for the fact that regions near the equator tend to be warmer than other regions on Earth?
O A. The sun's rays transfer less heat per square kilometer near the
equator.
O B. The sun's rays strike Earth's surface at an angle near the equator.
O C. The sun's rays are concentrated in a smaller area near the equator.
O D. The sun's rays are spread over a larger area near the equator.
SUBMIT

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.