Which statement is true regarding mechanical and electromagnetic waves?Both types of waves require a medium. Neither type of wave requires a medium. A mechanical wave requires a medium, but an electromagnetic wave does not. The speed of an electromagnetic wave can be affected by a medium, but the speed of a mechanical wave cannot.

Which animal group is the largest and contains more species from all the other living groups combined? is it mammals or

Which of the following systems in absorbing oxygen and releases carbon dioxide

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.