Let's see......
Picture #1:
- Antibody
Definition - Blood proteins created to defend the body against antigens.
Relation to antigens and agglutination - Antibodies are made up of antigens and are a part of agglutination.
Picture #2:
- Agglutination
Definition - Process that creates clumps caused by certain antibodies reacting with antigens.
Relation to antibodies and antigens - Caused by the mixture of antigens with antibodies.
Picture #3:
- Antigens
Definition - Molecule that is responsible for producing antigens in the host.
Relation to antibodies and agglutination - Antigens make up antibodies, are often targeted by antibodies, and mix with antibodies to cause agglutination
I did my best here and I hope this is in any way helpful!
