Which of the following is / are characteristic of saliva?
A. It contains `Na^(+) , k^(+) , Cl^(-) , HCO_(3)^(-) `. `B^-` Its pH is 7.2 nervous system. C. Characterised by salivary amylase and lingual lipase. D. About 60% starch is hydrolysed in buccal cavity by a-salivary amylase.

Options

A. A and B are correct
B. B and C are correct
C. B and D are correct
D. A and C are correct

Answer

To determine which of the following statements are characteristics of saliva, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Analyzing Option A:**
- **Statement:** "It contains Na^(+), K^(+), Cl^(-), HCO3^(-)."
- **Explanation:** Saliva does indeed contain various ions including sodium (Na^+), potassium (K^+), chloride (Cl^-), and bicarbonate (HCO3^-). Therefore, this statement is **correct**.

2. **Analyzing Option B:**
- **Statement:** "Its pH is 7.2."
- **Explanation:** The pH of saliva is typically around 6.8, which is slightly acidic. Since 7.2 is not the correct pH for saliva, this statement is **incorrect**.

3. **Analyzing Option C:**
- **Statement:** "Characterised by salivary amylase and lingual lipase."
- **Explanation:** Saliva contains salivary amylase, which initiates the digestion of carbohydrates, and lingual lipase, which begins the digestion of lipids. Thus, this statement is **correct**.

4. **Analyzing Option D:**
- **Statement:** "About 60% starch is hydrolysed in buccal cavity by salivary amylase."
- **Explanation:** It is known that salivary amylase hydrolyzes carbohydrates, but it is estimated that only about 30% of starch is hydrolyzed in the buccal cavity, not 60%. Therefore, this statement is **incorrect**.

### Conclusion:
Based on the analysis:
- Option A is correct.
- Option B is incorrect.
- Option C is correct.
- Option D is incorrect.

Thus, the correct answer is **A and C**.

### Final Answer:
The correct characteristics of saliva are **A and C**.

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