The kidneys in human beings are a part of the system for

Options

A. nutrition.
B. excretion.
C. respiration.
D. transportation

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Kidneys**: The kidneys are vital organs in the human body that play a crucial role in maintaining homeostasis. They are primarily involved in filtering blood and removing waste products.

2. **Structure of Kidneys**: The kidneys are composed of millions of tiny structures called nephrons. Nephrons are the functional units of the kidneys, responsible for the filtration of blood and the formation of urine.

3. **Function of Nephrons**: Each nephron filters blood, reabsorbs essential substances, and excretes waste products. This process is essential for regulating the body's fluid balance, electrolytes, and waste removal.

4. **Excretion Process**: The primary function of the kidneys is excretion, which involves the removal of metabolic waste products from the body. This includes substances like urea, creatinine, and excess salts.

5. **Conclusion**: Therefore, the kidneys in human beings are a part of the excretory system, which is responsible for the process of excretion.

**Final Answer**: The kidneys in human beings are a part of the excretory system.

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