The filtering unit in the human excretory system is called:

Options

A. nephron
B. neuron
C. nephridia
D. kidneyon

Answer

**Step-by-Step Solution:**

1. **Understanding the Excretory System**: The human excretory system is responsible for removing waste products from the body. It consists of various organs, including the kidneys, ureters, bladder, and urethra.

2. **Identifying the Filtering Unit**: The key function of the kidneys is to filter blood and produce urine. Within the kidneys, there are specific structures that perform the filtration process.

3. **Recognizing the Nephron**: The nephron is the basic structural and functional unit of the kidney. Each kidney contains about a million nephrons, which are responsible for filtering blood, reabsorbing necessary substances, and secreting waste products.

4. **Functions of the Nephron**: The nephron performs three main functions:
- **Filtration**: It filters waste products from the blood.
- **Reabsorption**: It reabsorbs essential nutrients and water back into the bloodstream.
- **Secretion**: It secretes additional waste products into the urine.

5. **Conclusion**: Since the nephron is the specific unit that filters waste in the human excretory system, the correct answer to the question is "nephron."

**Final Answer**: The filtering unit in the human excretory system is called the nephron.

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