Final answer:
Antibodies are large Y-shaped proteins in the blood that bind to antigens and mark invading foreign particles for destruction, making the statement true.
Step-by-step explanation:
Antibodies are indeed large proteins in the blood that play a crucial role in the immune system's defense against invading pathogens such as bacteria and viruses. These Y-shaped proteins are produced by immune cells called B cells. When a foreign particle, known as an antigen, is detected in the body, antibodies bind to it. The binding of an antibody to an antigen specifically marks the pathogen for destruction by other immune cells, such as phagocytes, through a process known as phagocytosis. Therefore, the statement that antibodies are large proteins in the blood that are effective in helping to destroy invading foreign particles is true.