Which sequence describes the order of structures through which air travels in the bird respiratory system? trachea, lung, anterior air sacs, bronchus, posterior air sacs, trachea trachea, bronchus, anterior air sacs, lung, posterior air sacs, trachea trachea, posterior air sacs, anterior air sacs, bronchus, lung, trachea trachea, bronchus, posterior air sacs, lung, anterior air sacs, trachea?

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.

45 points how are people today being protected from tsunamis? earthquake data is analyzed to detemrine if a tsunami is likely, and if so, warnings are sent out. areas in tsunami risk zones are no longer heavily populated. radar is used to measure wave heights regularly. meteorologists study the winds to determine if wave heights will be large.

What substance acts to prevent sudden ph changes in bodily fluids?