Angiotensin-converting enzyme is found only in the kidneys and converts angiotensinogen to angiotensin I. True or False

 

In response to inadequate oxygen transport, the kidneys and liver increase the synthesis and secretion of the glycoprotein hormone erythropoietin (EPO). This hormone is released into the systemic circulation to act as a chemical messenger. It serves as the primary stimulus for the acceleration of red blood cell production.

A. No: Red blood cells with no surface antigens are characteristic of blood type O. Because blood type AB is defined by the codominant expression of specific glycoproteins, the absence of antigens would contradict this blood group's classification. Type O individuals lack both A and B antigens on their erythrocyte membranes.

B. anti-A and anti-B: These are antibodies found in the plasma, not antigens on the red blood cell surface. Type AB individuals lack these antibodies in their plasma to prevent autodestruction of their own cells. Anti-A and anti-B antibodies are typical of type O plasma.

C. anti-A: This antibody is found in the plasma of individuals with type B blood. It is not an antigen found on the surface of AB red blood cells. Type AB blood contains the A antigen itself, so the presence of an anti-A antibody would lead to lethal agglutination.

D. anti-B: This antibody is present in the plasma of type A individuals and targets foreign B antigens. A person with type AB blood cannot possess anti-B antibodies because their cells express the B antigen. The presence of this antibody would cause a life-threatening immune reaction against their own erythrocytes.

E. A and B: Type AB blood is characterized by the presence of both A and B antigens on the surface of the red blood cells. Because both antigens are present, these individuals do not produce anti-A or anti-B antibodies in their plasma. This antigen profile makes them universal recipients of red blood cells.