Stratum corneum contains 

Options

A. Chitin
B. Keratin
C. Cellulose
D. Mucus

Answer

### Step-by-Step Solution:

1. **Understand the Question**: The question asks what the stratum corneum contains.

2. **Define Stratum Corneum**: The stratum corneum is the outermost layer of the epidermis, which is the outer layer of skin in animals.

3. **Identify the Composition**: The stratum corneum is primarily made up of dead or decaying cells. These cells are known as keratinocytes.

4. **Function of Keratinocytes**: Keratinocytes produce keratin, which is a type of protein that forms a protective layer in the epidermis.

5. **Evaluate the Options**:
- **Chitin**: This is a polysaccharide found in the exoskeletons of arthropods, not in the stratum corneum.
- **Keratin**: This is the correct answer, as it is the protein produced by keratinocytes in the stratum corneum.
- **Cellulose**: This is a carbohydrate found in plants, not in animals, making it an incorrect option.
- **Mucus**: This is secreted by goblet cells and is not a component of the stratum corneum.

6. **Conclusion**: The correct answer is **keratin**, as it is the primary component of the stratum corneum.

### Final Answer:
Stratum corneum contains **keratin**.

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