Blood Type Inheritance

What are Blood Types?

Blood types are determined by the presence or absence of specific antigens on the surface of red blood cells. The main blood type systems are the ABO system and the Rh factor.

ABO Blood Types

• Type A: Has A antigens and B antibodies.
• Type B: Has B antigens and A antibodies.
• Type AB: Has both A and B antigens, no antibodies (universal recipient).
• Type O: Has no antigens, both A and B antibodies (universal donor).

Rh Factor

The Rh factor can be either positive (+) or negative (-). Rh-positive means the Rh antigen is present, while Rh-negative means it is absent. The combination of ABO type and Rh factor determines a person's complete blood type.

Blood Type Inheritance

Blood type inheritance follows Mendelian genetics. Here are some common genotype combinations and their possible offspring blood types:

• Type A (IAIA or IAi) x Type B (IBIB or IBi) can produce: A, B, AB, O
• Type A (IAi) x Type O (ii) can produce: A, O
• Type AB (IAIB) x Type O (ii) can produce: A, B
• Type O (ii) x Type O (ii) can only produce: O