Final answer:
Researchers found that antibodies are produced by B-cells after activation by other immune cells. Antibodies specifically target and neutralize pathogens, making the immune system more efficient.
Step-by-step explanation:
Researchers investigating the immune system found that antibodies are produced by B-cells after they are activated by signals from other immune cells.
Activated B-cells undergo rapid growth and produce a clone of cells that all produce one specific type of antibody molecule.
The antibodies produced by plasma cells have the same antigen-binding site and specificity as their B-cell precursors.
They are secreted form of B-cell receptors and function as proteins that can bind to and neutralize specific pathogens.
Each antibody molecule specifically targets a particular pathogen to destroy it, making the immune system more efficient.
The immune system does not need to have its own gene for each antibody, as there are many different antibody molecules that can be made.