In an experiment, viruses were marked with radioactive DNA labeled with phosphorus-32, as shown on the left, or radioactive protein, which was labeled with sulfur-35, shown on the right. After the viruses infected bacteria, radiation was found inside only the bacteria that had been infected by the virus that had radioactive DNA.

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.

What type of organism is a one-celled organism that functions as a single unit? a. bi-celled b. single-celled c. pre-celled d. multi-celled

Which of the following are the functions of the integumentary system? yadda-yadda, the 1st answer is the brainliest. : )