MCQ Detailed View

Saliva is a watery liquid secreted in the mouth by the salivary glands. It helps in digestion, lubricating food, and protecting teeth from bacterial attack.

The pH of healthy human saliva is slightly alkaline, usually around 7.0 to 7.5. This mild alkalinity helps neutralize acids produced by bacteria in the mouth and protects tooth enamel from decay.

Saliva also contains important substances:

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  Enzymes like amylase that help in the digestion of starch

  
  


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  Mucus to lubricate food for easier swallowing

  
  


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  Antibacterial substances that help prevent infections

  
  

Other options are incorrect:

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  Slightly acidic – saliva is not acidic in a healthy person.

  
  


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  Slightly saline – while saliva contains salts, its defining feature is slightly alkaline pH, not salinity.

  
  


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  Neutral – true neutral pH is 7, but healthy saliva is slightly above 7.

  
  

In short, saliva of a healthy human is slightly alkaline, which helps maintain oral health, aids digestion, and protects teeth from acids. This concept is important in Biology, especially in human physiology and digestion.