The astronomer Johannes Kepler was the first scientist to explain that the eye works by focusing an image of the outside world onto the retina. However, we can see floaters just in front of the retina and white blood cells moving in the capillaries on the retina because of the shadows they cast and the light they let through. No focusing of an image is involved. Can you think of any other things and ways we might see that also do not rely on the focusing of an image on the retina?

Is their a picture that goes along with it? ?

They include lobsters and crabs

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.