Which is not correct

Options

A. Human saliva is near neutral
B. An adult secretes 1.0 -1.5 l of saliva per day
C. Saliva is secreted by six pairs of glands
D. Ptyalin breaks down cooked starch into maltose

Answer

To determine which statement is not correct regarding human saliva, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Human Saliva's pH**:
- Human saliva is generally considered to be near neutral, with a pH range of about 6.2 to 7.6. This means the statement "human saliva is near neutral" is correct.

2. **Daily Saliva Secretion**:
- An adult human typically secretes about 1.0 to 1.5 liters of saliva per day. This statement is also correct.

3. **Number of Salivary Glands**:
- Humans have three pairs of major salivary glands: the parotid, submandibular, and sublingual glands. Therefore, the statement "saliva is secreted by 6 pairs of glands" is incorrect, as there are only 3 pairs of major salivary glands.

4. **Function of Salivary Amylase**:
- Salivary amylase (also known as ptyalin) is an enzyme in saliva that breaks down starch into maltose. This statement is correct.

### Conclusion:
The statement that is not correct is: **"saliva is secreted by 6 pairs of glands."**