What is the main function of Malpighian tubules?

Answer

### Step-by-Step Solution:

1. **Identify the Organ**: The question asks about the Malpighian tubules. These are specialized structures found in certain organisms.

2. **Locate the Organism**: Malpighian tubules are primarily found in the phylum Arthropoda, which includes insects, arachnids, and crustaceans.

3. **Understand the Function**: The main function of Malpighian tubules is related to excretion. They play a crucial role in removing waste products from the body.

4. **Explain the Process**: In Arthropods, Malpighian tubules collect waste materials from the hemolymph (the equivalent of blood in these organisms) and convert them into a solid form, which is then excreted along with feces.

5. **Summarize the Main Function**: Therefore, the main function of Malpighian tubules is to assist in the excretion of nitrogenous wastes, helping to maintain osmotic balance in the organism.