Question

which of the following is produced by the immune system to identify foreign cells? antibodies antigens bacteria colored dye

Explanation:

To solve this, we analyze each option:

• Antibodies: Produced by the immune system (B - cells) to recognize and neutralize foreign cells (antigens).
• Antigens: Foreign substances that trigger an immune response, not produced by the immune system to identify others.
• Bacteria: Microorganisms, some pathogenic, not produced by the immune system for identification.
• Colored dye: Not related to the immune system's function.

So antibodies are produced by the immune system to identify foreign cells.

Answer:

A. antibodies