Why are biotechnology companies eager to design genetically modified organisms to express therapeutic proteins, particularly ones that would otherwise have to be isolated from blood products (e. g., human antithrombin) or animal organs (e. g., insulin, originally isolated from pig pancreas)?

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.

Apaleontologist finds a plant fossil that shows that the plant had seeds. what can the paleontologist conclude?

Human genes only differ by less than percent. a. 1 b. 6 c. 11 d. 16