ABO blood group system is given by

Options

A. (a) Landsteiner
B. (b) Wallace
C. (c) Hugo de Vries
D. (d) Lamarck

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the scientist associated with the discovery of the ABO blood group system.

2. **Reviewing the Options**: We have four options to consider:
- A) Landsteiner
- B) Wallace
- C) Hugo de Vries
- D) Lamarck

3. **Analyzing Option A (Landsteiner)**:
- Karl Landsteiner is known for discovering human blood groups in 1900.
- He identified the presence of different antigens on blood cells, which led to the classification of blood into different groups (A, B, AB, and O).
- His work laid the foundation for blood transfusion techniques based on blood compatibility.

4. **Analyzing Option B (Wallace)**:
- Alfred Wallace is known for his contributions to the theory of evolution, particularly in natural selection, but he did not contribute to the ABO blood group system.

5. **Analyzing Option C (Hugo de Vries)**:
- Hugo de Vries is recognized for his theory of mutation in the context of evolution, which is unrelated to blood groups.

6. **Analyzing Option D (Lamarck)**:
- Lamarck is known for his theory of inheritance of acquired traits, which also does not pertain to blood group classification.

7. **Conclusion**: After analyzing all the options, it is clear that the correct answer is **A) Landsteiner**, as he is the scientist who discovered the ABO blood group system.

**Final Answer**: The ABO blood group system is given by **A) Landsteiner**.

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