An abnormal rise in RBC count can be found during exercise and at high altitude to cope with the oxygen demand is known as

Options

A. Polycythemia
B. Thrombosis
C. Leukemia
D. Angina pectoris

Answer

To answer the question about the abnormal rise in RBC (red blood cell) count during exercise and at high altitudes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question is asking about a condition where there is an abnormal increase in the number of red blood cells (RBCs) in the body. This increase is observed in specific situations such as during exercise and at high altitudes.

2. **Identify the Function of RBCs**: RBCs are responsible for carrying oxygen throughout the body. An increase in RBC count can help meet the higher oxygen demands of the body during physical exertion (exercise) or in environments with lower oxygen levels (high altitude).

3. **Define the Condition**: The term used to describe an abnormal increase in RBC count is "polycythemia." Polycythemia can occur as a physiological response to increased oxygen demand, such as during intense exercise or when living at high altitudes.

4. **Evaluate the Options**: The options provided in the question are:
- A) Polycythemia
- B) Thrombosis
- C) Leukemia
- D) Angina pectoris

- **Polycythemia**: This is the correct answer as it directly relates to an increase in RBC count.
- **Thrombosis**: This refers to blood clotting and is related to platelets, not RBCs.
- **Leukemia**: This is a type of cancer that affects white blood cells (WBCs), not RBCs.
- **Angina pectoris**: This is chest pain due to insufficient oxygen to the heart muscle, not related to RBC count.

5. **Conclusion**: Based on the definitions and the context provided, the correct answer to the question is **polycythemia**.

### Final Answer:
The abnormal rise in RBC count during exercise and at high altitude to cope with oxygen demand is known as **polycythemia**.

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