Which term refers to the substance ejected through the mouth that can be used for diagnostic purposes in microbiology?

• A. Bile
• B. Serum
• C. Urine
• D. Sputum

Answer: (D)

Verified step by step guidance

1. Understand the question is asking for the term that describes a substance expelled through the mouth and used for diagnostic purposes in microbiology.
2. Review the options: Bile, Serum, Urine, and Sputum, and consider their definitions and sources in the body.
3. Recall that bile is a digestive fluid produced by the liver and stored in the gallbladder, not expelled through the mouth.
4. Serum is the clear fluid part of blood after clotting, not something ejected through the mouth.
5. Urine is expelled through the urinary tract, not the mouth.
6. Sputum is mucus and other matter coughed up from the respiratory tract through the mouth, often collected for microbiological analysis to diagnose infections.