In the ocean, why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity?

Because the Epipelagic Zone (or Euphotic Zone) receives enough sunlight for photosynthesis to occur. Since those tiny organisms who live there such as cyanobacteria and planktons are photosinthetic ones, they make up the base of the food chain and therefore are called primary producers. If they ceased to exist we would face several problems from loss of breathable air to food shortage.

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.