Final answer:
Antibodies, such as IgM and IgG, can bind to large parasites and play a crucial role in defense against them.
Step-by-step explanation:
Antibodies are large, Y-shaped proteins produced by B cells that recognize and bind to nonself antigens. In the context of parasitic infections, antibodies play a crucial role in defense. When it comes to large parasites, the antibodies that can bind to them are usually IgM and IgG. IgM antibodies have a pentameric structure and provide ten Fab binding sites per molecule, making them the most efficient antibody for agglutination. IgG antibodies have two Fab antigen-binding sites, which can bind to two separate pathogen cells, clumping them together and forming large aggregates that are easier for the immune system to eliminate.