AEMCA Practice Exam

Which condition would indicate a type O blood type with respect to antibodies?

1. A and B antibodies present

2. No antibodies present

3. Only A antibodies present

4. Only B antibodies present

The correct answer is: A and B antibodies present

The presence of both A and B antibodies in the plasma is characteristic of individuals with type O blood. Type O blood is defined by the absence of A and B antigens on the surface of red blood cells, which is coupled with the presence of antibodies against both A and B antigens in the plasma. This means that if a person with type O blood encounters A or B type blood, their immune system can recognize those foreign antigens and mount a response against them. In contrast, having no antibodies present would be indicative of type AB blood, as individuals with AB blood possess both A and B antigens on their red blood cells and do not produce antibodies against those antigens. Only A or only B antibodies present would indicate type A or type B blood types, respectively, which also possess the corresponding antigens. Thus, type O blood, characterized by the presence of both A and B antibodies without having either antigen, is correctly represented by the first option.