How are antigens recognized by immune system cells?

Plz ! for many generations farmers in north america have been choosing to cross corn plants with large ears of corn each year this results in the new generation of plants also growing large ears of corn. what is the technique called? a. selective breeding. b. natural selection. c. mitosis. d. asexual budding.

Witch theory suggests all living things are made up of cell or cells

What are the proteins in connectivity tissues of your foot examples of?