Excretory product of spider is

Options

A. Ammonia
B. Uric acid
C. Guanine
D. All the above

Answer

### Step-by-Step Solution:

1. **Identify the Organism**: The question asks about the excretory product of a spider. Spiders are classified as arachnids, which belong to the phylum Arthropoda.

2. **Understand the Excretory System**: In spiders, the excretory organs are known as Malpighian tubules. These structures play a crucial role in the excretion of waste products.

3. **Determine the Excretory Product**: The primary excretory product of spiders is guanine. This is a nitrogenous waste product that results from the metabolism of nucleotides.

4. **Compare with Other Options**:
- Ammonia is typically excreted by aquatic animals and is highly soluble in water.
- Uric acid is less soluble than ammonia but is not the primary excretory product in spiders.
- Guanine, being less soluble than uric acid, does not require water for its elimination, making it suitable for the terrestrial lifestyle of spiders.

5. **Conclude the Answer**: Based on the information gathered, the correct answer to the question "Excretory product of spider is" is guanine.

### Final Answer:
The excretory product of a spider is guanine.

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