Identify three ways that elliptical galaxies different than spiral galaxies.

Spiral galaxies have arms spiraling out from the central bulge of the galaxy and contain newer stars and has more gasses to form new stars. 
Elliptical galaxies are normally formed after spiral galaxies merge. The formation is an elliptical mass of stars without any arms. When galaxies merge, the process destroys gasses needed to form new stars.
Elliptical galaxy we would notice more older stars and less stars in the process of forming.

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.