PLEASE HELP!!! Biology encompasses all levels of biological organization, but scientists can specialize in studying a certain level. Which specific level(s) might a scientist might focus on if investigating genetic links to certain types of cancer?

This is one of the five kingdoms in the older biological succession. organisms in this kingdom are prokaryotic

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.

When a person is exercising the body needs to deliver increased amounts of oxygen to the muscles which component of blood ensures that the muscles will receive it