Which of the following best describes a portal of exit in microbiology?

• A. The location where a microorganism first enters the host body
• B. A chemical substance produced by microbes to inhibit competitors
• C. The site through which a microorganism leaves the host to spread to another host
• D. A structure on the surface of bacteria used for attachment

Answer: (C)

Verified step by step guidance

1. Understand the term 'portal of exit' in microbiology, which refers to the route or site through which a microorganism leaves the host organism.
2. Recall that microorganisms need to exit the host to spread infection to new hosts, making the portal of exit crucial in the transmission cycle of infectious diseases.
3. Identify common portals of exit such as respiratory secretions, blood, feces, urine, or skin lesions, which facilitate the spread of pathogens.
4. Compare the given options to see which one aligns with this definition: the location where a microorganism leaves the host to spread to another host.
5. Conclude that the correct description of a portal of exit is 'The site through which a microorganism leaves the host to spread to another host,' as it directly relates to the transmission of infection.