Name the most abundant protein in animal world.

Explanation

**Step-by-Step Solution:**

1. **Understanding Proteins**: Begin by defining what proteins are. Proteins are macronutrients essential for building muscles and maintaining body tissues. They are composed of smaller units called amino acids.

2. **Identifying the Most Abundant Protein**: The question specifically asks for the most abundant protein in the animal world. After considering various proteins, it is identified that collagen is the most abundant.

3. **Role of Collagen**: Collagen serves as the main structural protein in the extracellular matrix, which is crucial for various body parts. It is primarily found in connective tissues.

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