Which antigens does a person with blood type A− have on the surface of his or her erythrocytes?
a. A antigens
b. B antigens
c. Rh antigens
d. Both a and c are correct.
e. All of the above

Verified step by step guidance

1. Step 1: Understand the concept of blood type antigens. Blood type is determined by the presence or absence of specific antigens on the surface of erythrocytes (red blood cells). The two main antigens are A and B, and the Rh antigen determines whether the blood type is positive (+) or negative (−).
2. Step 2: Analyze the blood type given in the problem. A− blood type means the person has A antigens on their erythrocytes but does not have Rh antigens (negative Rh factor).
3. Step 3: Eliminate options that are inconsistent with the characteristics of A− blood type. For example, B antigens are not present in A− blood type, so option b can be excluded.
4. Step 4: Consider whether both A antigens and Rh antigens are present. Since the Rh antigen is absent in A− blood type, option d (both a and c) can also be excluded.
5. Step 5: Conclude that the correct answer must align with the presence of A antigens only, as this is the defining characteristic of A− blood type.

Key Concepts

Blood Type Antigens

Blood type antigens are specific molecules found on the surface of red blood cells (erythrocytes) that determine an individual's blood group. The main types are A and B antigens, which classify blood into types A, B, AB, and O. The presence or absence of these antigens is crucial for blood transfusions and compatibility.

Rh Factor

The Rh factor is another important antigen that can be present on the surface of red blood cells. It is denoted as positive (+) if the Rh antigen is present and negative (−) if it is absent. The Rh factor is significant in pregnancy and blood transfusions, as incompatibility can lead to serious health issues.

Blood Type A−

A person with blood type A− has A antigens on their erythrocytes and lacks B antigens. Additionally, the negative sign indicates the absence of the Rh factor. This means that their blood can safely receive type A or O blood, but not type B or AB, and they can only receive Rh− blood to avoid complications.