What are the function performed by nephrons?

Explanation

### Step-by-Step Solution:

1. **Introduction to Nephrons**:
- Nephrons are the functional units of the kidneys. Each kidney contains approximately one million nephrons, which are responsible for filtering blood and producing urine.

2. **Filtration**:
- The first function of nephrons is filtration. Blood enters the nephron through the glomerulus, where it is filtered. This process removes waste products, excess substances, and toxins from the blood, forming a filtrate that will eventually become urine.

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