Name the waste product excreted :
by the kidneys.

Answer

**Step-by-Step Solution:**

1. **Understanding Excretion**: Excretion is the biological process through which organisms eliminate metabolic waste products from their bodies. This is crucial for maintaining homeostasis and preventing the accumulation of harmful substances.

2. **Role of Kidneys**: The kidneys are vital organs in the human excretory system. They filter blood to remove waste products and excess substances, playing a key role in the body's waste management.

3. **Types of Nitrogenous Waste**: The primary waste products that the kidneys excrete are nitrogenous wastes. The three main types of nitrogenous wastes produced in the body are:
- Ammonia
- Uric Acid
- Urea

4. **Main Nitrogenous Waste in Humans**: Among these nitrogenous wastes, the main waste product excreted by the kidneys in humans is **Urea**.

5. **Process of Excretion**: The kidneys filter out urea, along with some salts and excess water, which are then excreted from the body in the form of urine.

6. **Conclusion**: Therefore, the waste product excreted by the kidneys is **Urea**.

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