Pathogenicity is best defined as:

• A. the ability of a microorganism to survive outside a host
• B. the degree of damage caused by a microorganism
• C. the ability of a microorganism to cause disease in a host
• D. the process by which microorganisms reproduce

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the term 'pathogenicity' in microbiology. It refers to the capacity of a microorganism to cause disease in a host organism.
2. Step 2: Differentiate 'pathogenicity' from related concepts such as 'virulence' (which is the degree of damage caused) and 'survival' (which relates to the microorganism's ability to live outside a host).
3. Step 3: Recognize that 'pathogenicity' specifically focuses on the ability to cause disease, not just survival or reproduction.
4. Step 4: Review the given options and identify that the correct definition aligns with 'the ability of a microorganism to cause disease in a host.'
5. Step 5: Confirm that other options like survival outside a host, degree of damage, or reproduction describe different microbiological concepts and are not definitions of pathogenicity.