A human plus all of its resident microbiota is referred to as a(n):

• A. pathogen
• B. holobiont
• C. symbiont
• D. commensal

Answer: (B)

Verified step by step guidance

1. Understand the term 'resident microbiota': these are the microorganisms that live on and inside the human body without causing disease under normal conditions.
2. Recognize that the question asks for a term that describes a human together with all its resident microbiota as a single entity.
3. Recall that 'pathogen' refers to a microorganism that causes disease, so it does not fit the description of the entire human-microbiota system.
4. Know that 'symbiont' refers to an organism involved in a symbiotic relationship, but it does not describe the combined human and microbiota as a whole.
5. Identify that 'holobiont' is the correct term used in microbiology to describe a host organism plus all of its associated microorganisms functioning as a single ecological unit.