The eyes of insects and the eyes of vertebrates were, until the early 1990s, considered to be a standard example of "analogous" structures. They perform the same function but have utterly different internal structures, suggesting that they evolved independently from a common ancestor that lacked eyes. Then the laboratory of Walter Gehring in Switzerland began to research genes that are [...]
Antibodies secreted by plasma cells may have several different effects - (1) They may interact with free (i.e., soluble) antigens causing precipitation; (2) They may interact with surface antigens of the pathogen (i.e., particulate antigens) causing agglutination; or (3) They may promote complement fixation. 1. Precipitation of Soluble Antigens: Antigens may have one or more antigenic determinants. If antigens contain [...]
Are you looking for an essay on ‘Lymphocytes and the Immune Response’ ? Find paragraphs, long and short essays on ‘Lymphocytes and the Immune Response’ especially written for school and college students. 1. Precipitation of Soluble Antigens: Antigens may have one or more antigenic determinants. If antigens contain one determinant, they are called monodeterminants; if they contain two determinants, they [...]