To answer the question "What does saliva contain?", we can break down the components of saliva step by step.
### Step-by-Step Solution:
1. **Identify the Composition of Saliva**: Saliva is primarily composed of water, making up about 98% of its content.
2. **List the Key Components**:
- **Electrolytes**: Saliva contains various electrolytes such as sodium, potassium, calcium, bicarbonate, and phosphate.
- **Mucus**: Mucus is present in saliva, which helps in lubricating food for easier swallowing.
- **Enzymes**: Saliva contains enzymes such as salivary amylase (which begins the digestion of carbohydrates) and lysozyme (which has antibacterial properties).
- **Other Components**: Saliva may also contain other substances like immunoglobulins and antimicrobial agents.
3. **Evaluate the Options**: Based on the components identified, we can evaluate the options provided in the question:
- **Option 1**: No mucus - Incorrect, as mucus is present in saliva.
- **Option 2**: Amylase, phthalene, lysozyme - Partially correct, but it misses other components.
- **Option 3**: Electrolytes, phthalene, lysozyme, and mucus - This option includes all the correct components.
- **Option 4**: Only salivary amylase - Incorrect, as it does not account for the other components.
4. **Conclusion**: The best option that accurately describes the composition of saliva is **Option 3**, which includes electrolytes, phthalene, lysozyme, and mucus.
### Final Answer:
Saliva contains electrolytes, mucus, lysozyme, and phthalene.
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