The spider webs are built of

Options

A. fat
B. fibroin protein
C. protamines
D. proteoglycans

Answer

**Step-by-Step Solution:**

1. **Understanding the Composition of Spider Webs:**
Spider webs are primarily made from silk, which is produced by spiders. This silk is a crucial material for constructing their webs.

2. **Identifying the Type of Silk:**
The silk produced by spiders contains a protein known as fibroin. Fibroin is a structural protein that contributes to the strength and elasticity of the silk.

3. **Properties of Spider Silk:**
Spider silk, made from fibroin, possesses remarkable properties. It is known for its high tensile strength, meaning it can withstand a lot of tension without breaking. Additionally, it is extensible, allowing it to stretch without snapping.

4. **Function of Spider Webs:**
The primary function of spider webs is to trap prey, such as small insects. The design and strength of the web enable spiders to catch and hold onto their food effectively.

5. **Conclusion:**
Therefore, the correct answer to the question about what spider webs are built of is "fibroin," which is a type of protein.

**Final Answer:**
Spider webs are built of fibroin, a protein that provides strength and elasticity.

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