ABO blood groups are dependent on _______ present on plamsa membrane of the red blood cells and protrude from its surface

Options

A. sugar polymers
B. starch
C. special lipids
D. phenols

Answer

**Step-by-Step Solution:**

1. **Understanding ABO Blood Groups**: The ABO blood group system is determined by the presence of specific antigens on the surface of red blood cells (RBCs). These antigens are genetically controlled.

2. **Identifying the Gene**: The ABO blood group is controlled by a gene known as the I gene (or ABO gene). This gene has three main alleles: IA, IB, and i (small i).

3. **Alleles and Their Dominance**: The alleles IA and IB are both dominant over the i allele. When an individual has either IA or IB, they will express the corresponding blood type (A or B). If an individual has both IA and IB, they express type AB blood, demonstrating co-dominance.

4. **Role of Sugar Polymers**: The antigens that define the ABO blood groups are actually sugar polymers (glycoproteins or glycolipids) that protrude from the plasma membrane of the RBCs. The specific type of sugar polymer produced is determined by the alleles present.

5. **Conclusion**: Since the question asks what the ABO blood groups depend on, the correct answer is "sugar polymers" that are present on the plasma membrane of the red blood cells.

**Final Answer**: ABO blood groups are dependent on **sugar polymers** present on the plasma membrane of the red blood cells and protrude from its surface.

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