True or False: The theory of evolution by natural selection is supported by a large body of scientific evidence.

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.

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above