Nitrogen-fixing bacteria live in in protective nodules (bumps) on the roots of some plants. a. mutualism. b. predation. c. commensalism. d. parasitism.

What is the function of nucleic acids

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.

Abiology teacher asks students to give examples of genetic variations that support the idea that changes in a population’s environment affect genetic variation. which is the least supportive example? a.changes in genetics in human populationsb.antibiotic resistance in bacteria populationsc.pesticide resistance in garden insectsd.changes in the color of the peppered moth population in england